From 879f40d193bb3c6c13930e88e3e9d5d7baf84d19 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 23 Nov 2013 17:21:49 -0500 Subject: sysfs, kernfs: introduce kernfs_remove[_by_name[_ns]]() Introduce kernfs removal interfaces - kernfs_remove() and kernfs_remove_by_name[_ns](). These are just renames of sysfs_remove() and sysfs_hash_and_remove(). No functional changes. v2: Dummy kernfs_remove_by_name_ns() for !CONFIG_SYSFS updated to return -ENOSYS instead of 0. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 79b5da2acbe1..5664410136ba 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -952,7 +952,7 @@ void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, { struct sysfs_dirent *dir_sd = kobj->sd; - sysfs_hash_and_remove(dir_sd, attr->name, ns); + kernfs_remove_by_name_ns(dir_sd, attr->name, ns); } EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); @@ -980,7 +980,7 @@ void sysfs_remove_file_from_group(struct kobject *kobj, else dir_sd = sysfs_get(kobj->sd); if (dir_sd) { - sysfs_hash_and_remove(dir_sd, attr->name, NULL); + kernfs_remove_by_name(dir_sd, attr->name); sysfs_put(dir_sd); } } @@ -1008,7 +1008,7 @@ EXPORT_SYMBOL_GPL(sysfs_create_bin_file); void sysfs_remove_bin_file(struct kobject *kobj, const struct bin_attribute *attr) { - sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL); + kernfs_remove_by_name(kobj->sd, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); -- cgit v1.2.3 From 5d60418e54751c856f5aecc308620fde9572e481 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Sat, 23 Nov 2013 17:21:52 -0500 Subject: sysfs, kernfs: introduce kernfs_setattr() Introduce kernfs setattr interface - kernfs_setattr(). sysfs_sd_setattr() is renamed to __kernfs_setattr() and kernfs_setattr() is a simple wrapper around it with sysfs_mutex locking. sysfs_chmod_file() is updated to get an explicit ref on kobj->sd and then invoke kernfs_setattr() so that it doesn't have to use internal interface. This patch doesn't introduce any behavior differences. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 5664410136ba..564abd201afb 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -922,19 +922,16 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, struct iattr newattrs; int rc; - mutex_lock(&sysfs_mutex); - - rc = -ENOENT; - sd = sysfs_find_dirent(kobj->sd, attr->name, NULL); + sd = sysfs_get_dirent(kobj->sd, attr->name); if (!sd) - goto out; + return -ENOENT; newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE; - rc = sysfs_sd_setattr(sd, &newattrs); - out: - mutex_unlock(&sysfs_mutex); + rc = kernfs_setattr(sd, &newattrs); + + sysfs_put(sd); return rc; } EXPORT_SYMBOL_GPL(sysfs_chmod_file); -- cgit v1.2.3 From 7c6e2d362c19f01e6d6c8be59d83a89722032884 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:14 -0500 Subject: sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv A directory sysfs_dirent points to the associated kobj. A regular or bin file points to the associated [bin_]attribute. This patch replaces sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with void * ->priv. This is to prepare for kernfs interface so that sysfs can specify the private data in the same way for directories and files. This lower debuggability but not by much - the whole thing was overlaid in a union anyway. If debuggability becomes an issue, we can later add ->priv accessors which explicitly check for the sysfs_dirent type and performs casting. This patch doesn't introduce any behavior difference. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 0f3f0a252a50..9b58d874c825 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -74,7 +74,7 @@ static struct sysfs_open_file *sysfs_of(struct file *file) */ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) { - struct kobject *kobj = sd->s_parent->s_dir.kobj; + struct kobject *kobj = sd->s_parent->priv; if (!sysfs_ignore_lockdep(sd)) lockdep_assert_held(sd); @@ -89,7 +89,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) static int sysfs_seq_show(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; - struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + struct kobject *kobj = of->sd->s_parent->priv; const struct sysfs_ops *ops; char *buf; ssize_t count; @@ -120,7 +120,7 @@ static int sysfs_seq_show(struct seq_file *sf, void *v) */ ops = sysfs_file_ops(of->sd); if (ops->show) - count = ops->show(kobj, of->sd->s_attr.attr, buf); + count = ops->show(kobj, of->sd->priv, buf); else count = 0; @@ -154,8 +154,8 @@ static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) { struct sysfs_open_file *of = sysfs_of(file); - struct bin_attribute *battr = of->sd->s_attr.bin_attr; - struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + struct bin_attribute *battr = of->sd->priv; + struct kobject *kobj = of->sd->s_parent->priv; loff_t size = file_inode(file)->i_size; int count = min_t(size_t, bytes, PAGE_SIZE); loff_t offs = *off; @@ -221,7 +221,7 @@ static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf, static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, size_t count) { - struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + struct kobject *kobj = of->sd->s_parent->priv; int rc = 0; /* @@ -236,7 +236,7 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, } if (sysfs_is_bin(of->sd)) { - struct bin_attribute *battr = of->sd->s_attr.bin_attr; + struct bin_attribute *battr = of->sd->priv; rc = -EIO; if (battr->write) @@ -245,7 +245,7 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, } else { const struct sysfs_ops *ops = sysfs_file_ops(of->sd); - rc = ops->store(kobj, of->sd->s_attr.attr, buf, count); + rc = ops->store(kobj, of->sd->priv, buf, count); } sysfs_put_active(of->sd); @@ -466,8 +466,8 @@ static const struct vm_operations_struct sysfs_bin_vm_ops = { static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma) { struct sysfs_open_file *of = sysfs_of(file); - struct bin_attribute *battr = of->sd->s_attr.bin_attr; - struct kobject *kobj = of->sd->s_parent->s_dir.kobj; + struct bin_attribute *battr = of->sd->priv; + struct kobject *kobj = of->sd->s_parent->priv; int rc; mutex_lock(&of->mutex); @@ -607,7 +607,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, static int sysfs_open_file(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; + struct kobject *kobj = attr_sd->s_parent->priv; struct sysfs_open_file *of; bool has_read, has_write, has_mmap; int error = -EACCES; @@ -617,7 +617,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) return -ENODEV; if (sysfs_is_bin(attr_sd)) { - struct bin_attribute *battr = attr_sd->s_attr.bin_attr; + struct bin_attribute *battr = attr_sd->priv; has_read = battr->read || battr->mmap; has_write = battr->write || battr->mmap; @@ -848,7 +848,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, return -ENOMEM; sd->s_ns = ns; - sd->s_attr.attr = (void *)attr; + sd->priv = (void *)attr; sysfs_dirent_init_lockdep(sd); sysfs_addrm_start(&acxt); -- cgit v1.2.3 From c2b19daf6760fae9d5db9e9d1683644728888293 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:16 -0500 Subject: sysfs, kernfs: prepare read path for kernfs We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges read path so that the kernfs and sysfs parts are separate. * Regular file read path is refactored such that kernfs_seq_start/next/stop/show() handle all the boilerplate work including locking and updating event count for poll, while sysfs_kf_seq_show() deals with interaction with kobj show method. * Bin file read path is refactored such that kernfs_file_direct_read() handles all the boilerplate work including buffer management and locking, while sysfs_kf_bin_read() deals with interaction with bin_attribute read method. kernfs_file_read() is added. It invokes either the seq_file or direct read path depending on the file type. This will eventually allow using the same file_operations for both file types, which is necessary to separate out kernfs. While this patch changes the order of some operations, it shouldn't change any visible behavior. v2: Dropped unnecessary zeroing of @count from sysfs_kf_seq_show(). Add comments explaining single_open() behavior. Both suggested by Pavel. v3: seq_stop() is called even after seq_start() failed. kernfs_seq_start() updated so that it doesn't unlock sysfs_open_file->mutex on failure so that kernfs_seq_stop() doesn't try to unlock an already unlocked mutex. Reported by Fengguang. Signed-off-by: Tejun Heo Cc: Pavel Machek Cc: Fengguang Wu Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 191 +++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 126 insertions(+), 65 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 9b58d874c825..b695b8b229fc 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -86,13 +86,13 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) * details like buffering and seeking. The following function pipes * sysfs_ops->show() result through seq_file. */ -static int sysfs_seq_show(struct seq_file *sf, void *v) +static int sysfs_kf_seq_show(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; struct kobject *kobj = of->sd->s_parent->priv; - const struct sysfs_ops *ops; - char *buf; + const struct sysfs_ops *ops = sysfs_file_ops(of->sd); ssize_t count; + char *buf; /* acquire buffer and ensure that it's >= PAGE_SIZE */ count = seq_get_buf(sf, &buf); @@ -102,33 +102,14 @@ static int sysfs_seq_show(struct seq_file *sf, void *v) } /* - * Need @of->sd for attr and ops, its parent for kobj. @of->mutex - * nests outside active ref and is just to ensure that the ops - * aren't called concurrently for the same open file. + * Invoke show(). Control may reach here via seq file lseek even + * if @ops->show() isn't implemented. */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) { - mutex_unlock(&of->mutex); - return -ENODEV; - } - - of->event = atomic_read(&of->sd->s_attr.open->event); - - /* - * Lookup @ops and invoke show(). Control may reach here via seq - * file lseek even if @ops->show() isn't implemented. - */ - ops = sysfs_file_ops(of->sd); - if (ops->show) + if (ops->show) { count = ops->show(kobj, of->sd->priv, buf); - else - count = 0; - - sysfs_put_active(of->sd); - mutex_unlock(&of->mutex); - - if (count < 0) - return count; + if (count < 0) + return count; + } /* * The code works fine with PAGE_SIZE return but it's likely to @@ -144,68 +125,146 @@ static int sysfs_seq_show(struct seq_file *sf, void *v) return 0; } -/* - * Read method for bin files. As reading a bin file can have side-effects, - * the exact offset and bytes specified in read(2) call should be passed to - * the read callback making it difficult to use seq_file. Implement - * simplistic custom buffering for bin files. - */ -static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf, - size_t bytes, loff_t *off) +static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, + size_t count, loff_t pos) { - struct sysfs_open_file *of = sysfs_of(file); struct bin_attribute *battr = of->sd->priv; struct kobject *kobj = of->sd->s_parent->priv; - loff_t size = file_inode(file)->i_size; - int count = min_t(size_t, bytes, PAGE_SIZE); - loff_t offs = *off; - char *buf; + loff_t size = file_inode(of->file)->i_size; - if (!bytes) + if (!count) return 0; if (size) { - if (offs > size) + if (pos > size) return 0; - if (offs + count > size) - count = size - offs; + if (pos + count > size) + count = size - pos; } - buf = kmalloc(count, GFP_KERNEL); + if (!battr->read) + return -EIO; + + return battr->read(of->file, kobj, battr, buf, pos, count); +} + +static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) +{ + struct sysfs_open_file *of = sf->private; + + /* + * @of->mutex nests outside active ref and is just to ensure that + * the ops aren't called concurrently for the same open file. + */ + mutex_lock(&of->mutex); + if (!sysfs_get_active(of->sd)) + return ERR_PTR(-ENODEV); + + /* + * The same behavior and code as single_open(). Returns !NULL if + * pos is at the beginning; otherwise, NULL. + */ + return NULL + !*ppos; +} + +static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) +{ + /* + * The same behavior and code as single_open(), always terminate + * after the initial read. + */ + ++*ppos; + return NULL; +} + +static void kernfs_seq_stop(struct seq_file *sf, void *v) +{ + struct sysfs_open_file *of = sf->private; + + sysfs_put_active(of->sd); + mutex_unlock(&of->mutex); +} + +static int kernfs_seq_show(struct seq_file *sf, void *v) +{ + struct sysfs_open_file *of = sf->private; + + of->event = atomic_read(&of->sd->s_attr.open->event); + + return sysfs_kf_seq_show(sf, v); +} + +static const struct seq_operations kernfs_seq_ops = { + .start = kernfs_seq_start, + .next = kernfs_seq_next, + .stop = kernfs_seq_stop, + .show = kernfs_seq_show, +}; + +/* + * As reading a bin file can have side-effects, the exact offset and bytes + * specified in read(2) call should be passed to the read callback making + * it difficult to use seq_file. Implement simplistic custom buffering for + * bin files. + */ +static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, + char __user *user_buf, size_t count, + loff_t *ppos) +{ + ssize_t len = min_t(size_t, count, PAGE_SIZE); + char *buf; + + buf = kmalloc(len, GFP_KERNEL); if (!buf) return -ENOMEM; - /* need of->sd for battr, its parent for kobj */ + /* + * @of->mutex nests outside active ref and is just to ensure that + * the ops aren't called concurrently for the same open file. + */ mutex_lock(&of->mutex); if (!sysfs_get_active(of->sd)) { - count = -ENODEV; + len = -ENODEV; mutex_unlock(&of->mutex); goto out_free; } - if (battr->read) - count = battr->read(file, kobj, battr, buf, offs, count); - else - count = -EIO; + len = sysfs_kf_bin_read(of, buf, len, *ppos); sysfs_put_active(of->sd); mutex_unlock(&of->mutex); - if (count < 0) + if (len < 0) goto out_free; - if (copy_to_user(userbuf, buf, count)) { - count = -EFAULT; + if (copy_to_user(user_buf, buf, len)) { + len = -EFAULT; goto out_free; } - pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); - - *off = offs + count; + *ppos += len; out_free: kfree(buf); - return count; + return len; +} + +/** + * kernfs_file_read - kernfs vfs read callback + * @file: file pointer + * @user_buf: data to write + * @count: number of bytes + * @ppos: starting offset + */ +static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct sysfs_open_file *of = sysfs_of(file); + + if (sysfs_is_bin(of->sd)) + return kernfs_file_direct_read(of, user_buf, count, ppos); + else + return seq_read(file, user_buf, count, ppos); } /** @@ -677,12 +736,14 @@ static int sysfs_open_file(struct inode *inode, struct file *file) * and readable regular files are the vast majority anyway. */ if (sysfs_is_bin(attr_sd)) - error = single_open(file, NULL, of); + error = seq_open(file, NULL); else - error = single_open(file, sysfs_seq_show, of); + error = seq_open(file, &kernfs_seq_ops); if (error) goto err_free; + ((struct seq_file *)file->private_data)->private = of; + /* seq_file clears PWRITE unconditionally, restore it if WRITE */ if (file->f_mode & FMODE_WRITE) file->f_mode |= FMODE_PWRITE; @@ -697,7 +758,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file) return 0; err_close: - single_release(inode, file); + seq_release(inode, file); err_free: kfree(of); err_out: @@ -711,7 +772,7 @@ static int sysfs_release(struct inode *inode, struct file *filp) struct sysfs_open_file *of = sysfs_of(filp); sysfs_put_open_dirent(sd, of); - single_release(inode, filp); + seq_release(inode, filp); kfree(of); return 0; @@ -816,7 +877,7 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) EXPORT_SYMBOL_GPL(sysfs_notify); const struct file_operations sysfs_file_operations = { - .read = seq_read, + .read = kernfs_file_read, .write = sysfs_write_file, .llseek = generic_file_llseek, .open = sysfs_open_file, @@ -825,7 +886,7 @@ const struct file_operations sysfs_file_operations = { }; const struct file_operations sysfs_bin_operations = { - .read = sysfs_bin_read, + .read = kernfs_file_read, .write = sysfs_write_file, .llseek = generic_file_llseek, .mmap = sysfs_bin_mmap, -- cgit v1.2.3 From 50b38ca086e4d9920eede98b871b971e9958d70d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:17 -0500 Subject: sysfs, kernfs: prepare write path for kernfs We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges write path so that the kernfs and sysfs parts are separate. kernfs_file_write() handles all boilerplate work including buffer management and locking and invokes sysfs_kf_write() or sysfs_kf_bin_write() depending on the file type which deals with the interaction with kobj store or bin_attribute write method. While this patch changes the order of some operations, it shouldn't change any visible behavior. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 103 +++++++++++++++++++++++++++----------------------------- 1 file changed, 50 insertions(+), 53 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index b695b8b229fc..2f849e82c0eb 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -267,61 +267,50 @@ static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, return seq_read(file, user_buf, count, ppos); } -/** - * flush_write_buffer - push buffer to kobject - * @of: open file - * @buf: data buffer for file - * @off: file offset to write to - * @count: number of bytes - * - * Get the correct pointers for the kobject and the attribute we're dealing - * with, then call the store() method for it with @buf. - */ -static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, - size_t count) +/* kernfs write callback for regular sysfs files */ +static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, + size_t count, loff_t pos) { + const struct sysfs_ops *ops = sysfs_file_ops(of->sd); struct kobject *kobj = of->sd->s_parent->priv; - int rc = 0; - /* - * Need @of->sd for attr and ops, its parent for kobj. @of->mutex - * nests outside active ref and is just to ensure that the ops - * aren't called concurrently for the same open file. - */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) { - mutex_unlock(&of->mutex); - return -ENODEV; - } + if (!count) + return 0; - if (sysfs_is_bin(of->sd)) { - struct bin_attribute *battr = of->sd->priv; + return ops->store(kobj, of->sd->priv, buf, count); +} - rc = -EIO; - if (battr->write) - rc = battr->write(of->file, kobj, battr, buf, off, - count); - } else { - const struct sysfs_ops *ops = sysfs_file_ops(of->sd); +/* kernfs write callback for bin sysfs files */ +static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, + size_t count, loff_t pos) +{ + struct bin_attribute *battr = of->sd->priv; + struct kobject *kobj = of->sd->s_parent->priv; + loff_t size = file_inode(of->file)->i_size; - rc = ops->store(kobj, of->sd->priv, buf, count); + if (size) { + if (size <= pos) + return 0; + count = min_t(ssize_t, count, size - pos); } + if (!count) + return 0; - sysfs_put_active(of->sd); - mutex_unlock(&of->mutex); + if (!battr->write) + return -EIO; - return rc; + return battr->write(of->file, kobj, battr, buf, pos, count); } /** - * sysfs_write_file - write an attribute + * kernfs_file_write - kernfs vfs write callback * @file: file pointer * @user_buf: data to write * @count: number of bytes * @ppos: starting offset * - * Copy data in from userland and pass it to the matching - * sysfs_ops->store() by invoking flush_write_buffer(). + * Copy data in from userland and pass it to the matching kernfs write + * operation. * * There is no easy way for us to know if userspace is only doing a partial * write, so we don't support them. We expect the entire buffer to come on @@ -329,23 +318,13 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off, * modify only the the value you're changing, then write entire buffer * back. */ -static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf, - size_t count, loff_t *ppos) +static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, + size_t count, loff_t *ppos) { struct sysfs_open_file *of = sysfs_of(file); ssize_t len = min_t(size_t, count, PAGE_SIZE); - loff_t size = file_inode(file)->i_size; char *buf; - if (sysfs_is_bin(of->sd) && size) { - if (size <= *ppos) - return 0; - len = min_t(ssize_t, len, size - *ppos); - } - - if (!len) - return 0; - buf = kmalloc(len + 1, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -356,7 +335,25 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf, } buf[len] = '\0'; /* guarantee string termination */ - len = flush_write_buffer(of, buf, *ppos, len); + /* + * @of->mutex nests outside active ref and is just to ensure that + * the ops aren't called concurrently for the same open file. + */ + mutex_lock(&of->mutex); + if (!sysfs_get_active(of->sd)) { + mutex_unlock(&of->mutex); + len = -ENODEV; + goto out_free; + } + + if (sysfs_is_bin(of->sd)) + len = sysfs_kf_bin_write(of, buf, len, *ppos); + else + len = sysfs_kf_write(of, buf, len, *ppos); + + sysfs_put_active(of->sd); + mutex_unlock(&of->mutex); + if (len > 0) *ppos += len; out_free: @@ -878,7 +875,7 @@ EXPORT_SYMBOL_GPL(sysfs_notify); const struct file_operations sysfs_file_operations = { .read = kernfs_file_read, - .write = sysfs_write_file, + .write = kernfs_file_write, .llseek = generic_file_llseek, .open = sysfs_open_file, .release = sysfs_release, @@ -887,7 +884,7 @@ const struct file_operations sysfs_file_operations = { const struct file_operations sysfs_bin_operations = { .read = kernfs_file_read, - .write = sysfs_write_file, + .write = kernfs_file_write, .llseek = generic_file_llseek, .mmap = sysfs_bin_mmap, .open = sysfs_open_file, -- cgit v1.2.3 From fdbffaa478fc77e999cbe2ac0dcfbf609103e675 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:18 -0500 Subject: sysfs, kernfs: prepare mmap path for kernfs We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch rearranges mmap path so that the kernfs and sysfs parts are separate. sysfs_kf_bin_mmap() which handles the interaction with bin_attribute mmap method is factored out of sysfs_bin_mmap(), which is renamed to kernfs_file_mmap(). All vma ops are renamed accordingly. sysfs_bin_mmap() is updated such that it can be used for both file types. This will eventually allow using the same file_operations for both file types, which is necessary to separate out kernfs. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 69 ++++++++++++++++++++++++++++++++------------------------- 1 file changed, 39 insertions(+), 30 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 2f849e82c0eb..2e24e89bd92b 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -361,7 +361,19 @@ out_free: return len; } -static void sysfs_bin_vma_open(struct vm_area_struct *vma) +static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, + struct vm_area_struct *vma) +{ + struct bin_attribute *battr = of->sd->priv; + struct kobject *kobj = of->sd->s_parent->priv; + + if (!battr->mmap) + return -ENODEV; + + return battr->mmap(of->file, kobj, battr, vma); +} + +static void kernfs_vma_open(struct vm_area_struct *vma) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -378,7 +390,7 @@ static void sysfs_bin_vma_open(struct vm_area_struct *vma) sysfs_put_active(of->sd); } -static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) +static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -398,8 +410,8 @@ static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf) return ret; } -static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma, - struct vm_fault *vmf) +static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma, + struct vm_fault *vmf) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -421,8 +433,8 @@ static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma, return ret; } -static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr, - void *buf, int len, int write) +static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -443,8 +455,8 @@ static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr, } #ifdef CONFIG_NUMA -static int sysfs_bin_set_policy(struct vm_area_struct *vma, - struct mempolicy *new) +static int kernfs_vma_set_policy(struct vm_area_struct *vma, + struct mempolicy *new) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -464,8 +476,8 @@ static int sysfs_bin_set_policy(struct vm_area_struct *vma, return ret; } -static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma, - unsigned long addr) +static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, + unsigned long addr) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -485,8 +497,9 @@ static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma, return pol; } -static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, - const nodemask_t *to, unsigned long flags) +static int kernfs_vma_migrate(struct vm_area_struct *vma, + const nodemask_t *from, const nodemask_t *to, + unsigned long flags) { struct file *file = vma->vm_file; struct sysfs_open_file *of = sysfs_of(file); @@ -507,36 +520,31 @@ static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from, } #endif -static const struct vm_operations_struct sysfs_bin_vm_ops = { - .open = sysfs_bin_vma_open, - .fault = sysfs_bin_fault, - .page_mkwrite = sysfs_bin_page_mkwrite, - .access = sysfs_bin_access, +static const struct vm_operations_struct kernfs_vm_ops = { + .open = kernfs_vma_open, + .fault = kernfs_vma_fault, + .page_mkwrite = kernfs_vma_page_mkwrite, + .access = kernfs_vma_access, #ifdef CONFIG_NUMA - .set_policy = sysfs_bin_set_policy, - .get_policy = sysfs_bin_get_policy, - .migrate = sysfs_bin_migrate, + .set_policy = kernfs_vma_set_policy, + .get_policy = kernfs_vma_get_policy, + .migrate = kernfs_vma_migrate, #endif }; -static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma) +static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) { struct sysfs_open_file *of = sysfs_of(file); - struct bin_attribute *battr = of->sd->priv; - struct kobject *kobj = of->sd->s_parent->priv; int rc; mutex_lock(&of->mutex); - /* need of->sd for battr, its parent for kobj */ rc = -ENODEV; if (!sysfs_get_active(of->sd)) goto out_unlock; - if (!battr->mmap) - goto out_put; - - rc = battr->mmap(file, kobj, battr, vma); + if (sysfs_is_bin(of->sd)) + rc = sysfs_kf_bin_mmap(of, vma); if (rc) goto out_put; @@ -563,7 +571,7 @@ static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma) rc = 0; of->mmapped = 1; of->vm_ops = vma->vm_ops; - vma->vm_ops = &sysfs_bin_vm_ops; + vma->vm_ops = &kernfs_vm_ops; out_put: sysfs_put_active(of->sd); out_unlock: @@ -877,6 +885,7 @@ const struct file_operations sysfs_file_operations = { .read = kernfs_file_read, .write = kernfs_file_write, .llseek = generic_file_llseek, + .mmap = kernfs_file_mmap, .open = sysfs_open_file, .release = sysfs_release, .poll = sysfs_poll, @@ -886,7 +895,7 @@ const struct file_operations sysfs_bin_operations = { .read = kernfs_file_read, .write = kernfs_file_write, .llseek = generic_file_llseek, - .mmap = sysfs_bin_mmap, + .mmap = kernfs_file_mmap, .open = sysfs_open_file, .release = sysfs_release, .poll = sysfs_poll, -- cgit v1.2.3 From c6fb449515f23edea828fb90a460d3622e261dba Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:19 -0500 Subject: sysfs, kernfs: prepare open, release, poll paths for kernfs We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch prepares the rest - open, release and poll. There isn't much to do. Just renaming is enough. As sysfs_file_operations and sysfs_bin_operations are identical now, use the same file_operations for both - kernfs_file_operations. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 2e24e89bd92b..a43df04c81f9 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -668,7 +668,7 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, kfree(od); } -static int sysfs_open_file(struct inode *inode, struct file *file) +static int kernfs_file_open(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; struct kobject *kobj = attr_sd->s_parent->priv; @@ -771,7 +771,7 @@ err_out: return error; } -static int sysfs_release(struct inode *inode, struct file *filp) +static int kernfs_file_release(struct inode *inode, struct file *filp) { struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; struct sysfs_open_file *of = sysfs_of(filp); @@ -822,7 +822,7 @@ void sysfs_unmap_bin_file(struct sysfs_dirent *sd) * to see if it supports poll (Neither 'poll' nor 'select' return * an appropriate error code). When in doubt, set a suitable timeout value. */ -static unsigned int sysfs_poll(struct file *filp, poll_table *wait) +static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) { struct sysfs_open_file *of = sysfs_of(filp); struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; @@ -881,24 +881,14 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) } EXPORT_SYMBOL_GPL(sysfs_notify); -const struct file_operations sysfs_file_operations = { +const struct file_operations kernfs_file_operations = { .read = kernfs_file_read, .write = kernfs_file_write, .llseek = generic_file_llseek, .mmap = kernfs_file_mmap, - .open = sysfs_open_file, - .release = sysfs_release, - .poll = sysfs_poll, -}; - -const struct file_operations sysfs_bin_operations = { - .read = kernfs_file_read, - .write = kernfs_file_write, - .llseek = generic_file_llseek, - .mmap = kernfs_file_mmap, - .open = sysfs_open_file, - .release = sysfs_release, - .poll = sysfs_poll, + .open = kernfs_file_open, + .release = kernfs_file_release, + .poll = kernfs_file_poll, }; int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, -- cgit v1.2.3 From dd8a5b036b6e8d50854e130555f90f062c5eacec Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:20 -0500 Subject: sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h sysfs_open_file will be used as the primary handle for kernfs methods. Move its definition from fs/sysfs/file.c to include/linux/kernfs.h and mark the public and private fields. This is pure relocation. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 11 ----------- 1 file changed, 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a43df04c81f9..acba5835577e 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -47,17 +47,6 @@ struct sysfs_open_dirent { struct list_head files; /* goes through sysfs_open_file.list */ }; -struct sysfs_open_file { - struct sysfs_dirent *sd; - struct file *file; - struct mutex mutex; - int event; - struct list_head list; - - bool mmapped; - const struct vm_operations_struct *vm_ops; -}; - static bool sysfs_is_bin(struct sysfs_dirent *sd) { return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR; -- cgit v1.2.3 From f6acf8bb6a40ba3bfcf542e4c4c9e8968c8cb57a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:21 -0500 Subject: sysfs, kernfs: introduce kernfs_ops We're in the process of separating out core sysfs functionality into kernfs which will deal with sysfs_dirents directly. This patch introduces kernfs_ops which hosts methods kernfs users implement and updates fs/sysfs/file.c such that sysfs_kf_*() functions populate kernfs_ops and kernfs_file_*() functions call the matching entries from kernfs_ops. kernfs_ops contains the following groups of methods. * seq_show() - for kernfs files which use seq_file for reads. * read() - for direct read implementations. Used iff seq_show() is not implemented. * write() - for writes. * mmap() - for mmaps. Notes: * sysfs_elem_attr->ops is added so that kernfs_ops can be accessed from sysfs_dirent. kernfs_ops() helper is added to verify locking and access the field. * SYSFS_FLAG_HAS_(SEQ_SHOW|MMAP) added. sd->s_attr->ops is accessible only while holding active_ref and there are cases where we want to take different actions depending on which ops are implemented. These two flags cache whether the two ops are implemented for those. * kernfs_file_*() no longer test sysfs type but chooses different behaviors depending on which methods in kernfs_ops are implemented. The conversions are trivial except for the open path. As kernfs_file_open() now decides whether to allow read/write accesses depending on the kernfs_ops implemented, the presence of methods in kobjs and attribute_bin should be propagated to kernfs_ops. sysfs_add_file_mode_ns() is updated so that it propagates presence / absence of the callbacks through _empty, _ro, _wo, _rw kernfs_ops. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 146 +++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 112 insertions(+), 34 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index acba5835577e..cbebc335af8c 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -57,6 +57,17 @@ static struct sysfs_open_file *sysfs_of(struct file *file) return ((struct seq_file *)file->private_data)->private; } +/* + * Determine the kernfs_ops for the given sysfs_dirent. This function must + * be called while holding an active reference. + */ +static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) +{ + if (!sysfs_ignore_lockdep(sd)) + lockdep_assert_held(sd); + return sd->s_attr.ops; +} + /* * Determine ktype->sysfs_ops for the given sysfs_dirent. This function * must be called while holding an active reference. @@ -180,7 +191,7 @@ static int kernfs_seq_show(struct seq_file *sf, void *v) of->event = atomic_read(&of->sd->s_attr.open->event); - return sysfs_kf_seq_show(sf, v); + return of->sd->s_attr.ops->seq_show(sf, v); } static const struct seq_operations kernfs_seq_ops = { @@ -201,6 +212,7 @@ static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, loff_t *ppos) { ssize_t len = min_t(size_t, count, PAGE_SIZE); + const struct kernfs_ops *ops; char *buf; buf = kmalloc(len, GFP_KERNEL); @@ -218,7 +230,11 @@ static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, goto out_free; } - len = sysfs_kf_bin_read(of, buf, len, *ppos); + ops = kernfs_ops(of->sd); + if (ops->read) + len = ops->read(of, buf, len, *ppos); + else + len = -EINVAL; sysfs_put_active(of->sd); mutex_unlock(&of->mutex); @@ -250,10 +266,10 @@ static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, { struct sysfs_open_file *of = sysfs_of(file); - if (sysfs_is_bin(of->sd)) - return kernfs_file_direct_read(of, user_buf, count, ppos); - else + if (of->sd->s_flags & SYSFS_FLAG_HAS_SEQ_SHOW) return seq_read(file, user_buf, count, ppos); + else + return kernfs_file_direct_read(of, user_buf, count, ppos); } /* kernfs write callback for regular sysfs files */ @@ -312,6 +328,7 @@ static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, { struct sysfs_open_file *of = sysfs_of(file); ssize_t len = min_t(size_t, count, PAGE_SIZE); + const struct kernfs_ops *ops; char *buf; buf = kmalloc(len + 1, GFP_KERNEL); @@ -335,10 +352,11 @@ static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, goto out_free; } - if (sysfs_is_bin(of->sd)) - len = sysfs_kf_bin_write(of, buf, len, *ppos); + ops = kernfs_ops(of->sd); + if (ops->write) + len = ops->write(of, buf, len, *ppos); else - len = sysfs_kf_write(of, buf, len, *ppos); + len = -EINVAL; sysfs_put_active(of->sd); mutex_unlock(&of->mutex); @@ -524,6 +542,7 @@ static const struct vm_operations_struct kernfs_vm_ops = { static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) { struct sysfs_open_file *of = sysfs_of(file); + const struct kernfs_ops *ops; int rc; mutex_lock(&of->mutex); @@ -532,8 +551,9 @@ static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) if (!sysfs_get_active(of->sd)) goto out_unlock; - if (sysfs_is_bin(of->sd)) - rc = sysfs_kf_bin_mmap(of, vma); + ops = kernfs_ops(of->sd); + if (ops->mmap) + rc = ops->mmap(of, vma); if (rc) goto out_put; @@ -660,34 +680,19 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd, static int kernfs_file_open(struct inode *inode, struct file *file) { struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - struct kobject *kobj = attr_sd->s_parent->priv; + const struct kernfs_ops *ops; struct sysfs_open_file *of; bool has_read, has_write, has_mmap; int error = -EACCES; - /* need attr_sd for attr and ops, its parent for kobj */ if (!sysfs_get_active(attr_sd)) return -ENODEV; - if (sysfs_is_bin(attr_sd)) { - struct bin_attribute *battr = attr_sd->priv; + ops = kernfs_ops(attr_sd); - has_read = battr->read || battr->mmap; - has_write = battr->write || battr->mmap; - has_mmap = battr->mmap; - } else { - const struct sysfs_ops *ops = sysfs_file_ops(attr_sd); - - /* every kobject with an attribute needs a ktype assigned */ - if (WARN(!ops, KERN_ERR - "missing sysfs attribute operations for kobject: %s\n", - kobject_name(kobj))) - goto err_out; - - has_read = ops->show; - has_write = ops->store; - has_mmap = false; - } + has_read = ops->seq_show || ops->read || ops->mmap; + has_write = ops->write || ops->mmap; + has_mmap = ops->mmap; /* check perms and supported operations */ if ((file->f_mode & FMODE_WRITE) && @@ -729,10 +734,10 @@ static int kernfs_file_open(struct inode *inode, struct file *file) * seq_file or is not requested. This unifies private data access * and readable regular files are the vast majority anyway. */ - if (sysfs_is_bin(attr_sd)) - error = seq_open(file, NULL); - else + if (ops->seq_show) error = seq_open(file, &kernfs_seq_ops); + else + error = seq_open(file, NULL); if (error) goto err_free; @@ -777,7 +782,7 @@ void sysfs_unmap_bin_file(struct sysfs_dirent *sd) struct sysfs_open_dirent *od; struct sysfs_open_file *of; - if (!sysfs_is_bin(sd)) + if (!(sd->s_flags & SYSFS_FLAG_HAS_MMAP)) return; spin_lock_irq(&sysfs_open_dirent_lock); @@ -880,23 +885,96 @@ const struct file_operations kernfs_file_operations = { .poll = kernfs_file_poll, }; +static const struct kernfs_ops sysfs_file_kfops_empty = { +}; + +static const struct kernfs_ops sysfs_file_kfops_ro = { + .seq_show = sysfs_kf_seq_show, +}; + +static const struct kernfs_ops sysfs_file_kfops_wo = { + .write = sysfs_kf_write, +}; + +static const struct kernfs_ops sysfs_file_kfops_rw = { + .seq_show = sysfs_kf_seq_show, + .write = sysfs_kf_write, +}; + +static const struct kernfs_ops sysfs_bin_kfops_ro = { + .read = sysfs_kf_bin_read, +}; + +static const struct kernfs_ops sysfs_bin_kfops_wo = { + .write = sysfs_kf_bin_write, +}; + +static const struct kernfs_ops sysfs_bin_kfops_rw = { + .read = sysfs_kf_bin_read, + .write = sysfs_kf_bin_write, + .mmap = sysfs_kf_bin_mmap, +}; + int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, const struct attribute *attr, int type, umode_t amode, const void *ns) { umode_t mode = (amode & S_IALLUGO) | S_IFREG; + const struct kernfs_ops *ops; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; int rc; + if (type == SYSFS_KOBJ_ATTR) { + struct kobject *kobj = dir_sd->priv; + const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; + + /* every kobject with an attribute needs a ktype assigned */ + if (WARN(!sysfs_ops, KERN_ERR + "missing sysfs attribute operations for kobject: %s\n", + kobject_name(kobj))) + return -EINVAL; + + if (sysfs_ops->show && sysfs_ops->store) + ops = &sysfs_file_kfops_rw; + else if (sysfs_ops->show) + ops = &sysfs_file_kfops_ro; + else if (sysfs_ops->store) + ops = &sysfs_file_kfops_wo; + else + ops = &sysfs_file_kfops_empty; + } else { + struct bin_attribute *battr = (void *)attr; + + if ((battr->read && battr->write) || battr->mmap) + ops = &sysfs_bin_kfops_rw; + else if (battr->read) + ops = &sysfs_bin_kfops_ro; + else if (battr->write) + ops = &sysfs_bin_kfops_wo; + else + ops = &sysfs_file_kfops_empty; + } + sd = sysfs_new_dirent(attr->name, mode, type); if (!sd) return -ENOMEM; + sd->s_attr.ops = ops; sd->s_ns = ns; sd->priv = (void *)attr; sysfs_dirent_init_lockdep(sd); + /* + * sd->s_attr.ops is accesible only while holding active ref. We + * need to know whether some ops are implemented outside active + * ref. Cache their existence in flags. + */ + if (ops->seq_show) + sd->s_flags |= SYSFS_FLAG_HAS_SEQ_SHOW; + if (ops->mmap) + sd->s_flags |= SYSFS_FLAG_HAS_MMAP; + sysfs_addrm_start(&acxt); rc = sysfs_add_one(&acxt, sd, dir_sd); sysfs_addrm_finish(&acxt); -- cgit v1.2.3 From 471bd7b78bd56c580e91e00a0f656ca922ab3b3c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:22 -0500 Subject: sysfs, kernfs: add sysfs_dirent->s_attr.size sysfs sets the size of regular files unconditionally at PAGE_SIZE and takes the size of bin files from bin_attribute. The latter is a pretty bad interface which forces bin_attribute users to create a separate copy of bin_attribute for each instance of the file - e.g. pci resource files. Add sysfs_dirent->s_attr.size so that the size can be specified separately. This unifies inode init paths of ATTR and BIN_ATTR identical and allows for generic size handling for kernfs. Unfortunately, this grows the size of sysfs_dirent by sizeof(loff_t). Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index cbebc335af8c..0b0cec8e9d8f 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -923,6 +923,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, const struct kernfs_ops *ops; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; + loff_t size; int rc; if (type == SYSFS_KOBJ_ATTR) { @@ -943,6 +944,8 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, ops = &sysfs_file_kfops_wo; else ops = &sysfs_file_kfops_empty; + + size = PAGE_SIZE; } else { struct bin_attribute *battr = (void *)attr; @@ -954,6 +957,8 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, ops = &sysfs_bin_kfops_wo; else ops = &sysfs_file_kfops_empty; + + size = battr->size; } sd = sysfs_new_dirent(attr->name, mode, type); @@ -961,6 +966,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, return -ENOMEM; sd->s_attr.ops = ops; + sd->s_attr.size = size; sd->s_ns = ns; sd->priv = (void *)attr; sysfs_dirent_init_lockdep(sd); -- cgit v1.2.3 From a7dc66dfb4c6d6c1d7c14d5106ce467f1dbd4eba Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:23 -0500 Subject: sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR After kernfs_ops and sysfs_dirent->s_attr.size addition, the distinction between SYSFS_KOBJ_BIN_ATTR and SYSFS_KOBJ_ATTR is only necessary while creating files to decide which kernfs_ops to use. Afterwards, they behave exactly the same. This patch removes SYSFS_KOBJ_BIN_ATTR along with sysfs_is_bin(). sysfs_add_file[_mode_ns]() are updated to take bool @is_bin instead of @type. This patch doesn't introduce any behavior changes. This completely isolates the distinction between the two sysfs file types in the sysfs layer proper. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 0b0cec8e9d8f..e2ce6743113a 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -47,11 +47,6 @@ struct sysfs_open_dirent { struct list_head files; /* goes through sysfs_open_file.list */ }; -static bool sysfs_is_bin(struct sysfs_dirent *sd) -{ - return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR; -} - static struct sysfs_open_file *sysfs_of(struct file *file) { return ((struct seq_file *)file->private_data)->private; @@ -916,7 +911,7 @@ static const struct kernfs_ops sysfs_bin_kfops_rw = { }; int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, - const struct attribute *attr, int type, + const struct attribute *attr, bool is_bin, umode_t amode, const void *ns) { umode_t mode = (amode & S_IALLUGO) | S_IFREG; @@ -926,7 +921,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, loff_t size; int rc; - if (type == SYSFS_KOBJ_ATTR) { + if (!is_bin) { struct kobject *kobj = dir_sd->priv; const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; @@ -961,7 +956,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, size = battr->size; } - sd = sysfs_new_dirent(attr->name, mode, type); + sd = sysfs_new_dirent(attr->name, mode, SYSFS_KOBJ_ATTR); if (!sd) return -ENOMEM; @@ -991,11 +986,10 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, return rc; } - int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, - int type) + bool is_bin) { - return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL); + return sysfs_add_file_mode_ns(dir_sd, attr, is_bin, attr->mode, NULL); } /** @@ -1009,8 +1003,7 @@ int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr, { BUG_ON(!kobj || !kobj->sd || !attr); - return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR, - attr->mode, ns); + return sysfs_add_file_mode_ns(kobj->sd, attr, false, attr->mode, ns); } EXPORT_SYMBOL_GPL(sysfs_create_file_ns); @@ -1049,7 +1042,7 @@ int sysfs_add_file_to_group(struct kobject *kobj, if (!dir_sd) return -ENOENT; - error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR); + error = sysfs_add_file(dir_sd, attr, false); sysfs_put(dir_sd); return error; @@ -1141,7 +1134,7 @@ int sysfs_create_bin_file(struct kobject *kobj, { BUG_ON(!kobj || !kobj->sd || !attr); - return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR); + return sysfs_add_file(kobj->sd, &attr->attr, true); } EXPORT_SYMBOL_GPL(sysfs_create_bin_file); -- cgit v1.2.3 From 496f73944a4a974f89d48920bf368aec8841b195 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:24 -0500 Subject: sysfs, kernfs: introduce kernfs_create_file[_ns]() Introduce kernfs interface to create a file which takes and returns sysfs_dirents. The actual file creation part is separated out from sysfs_add_file_mode_ns() into kernfs_create_file_ns(). The former now only decides the kernfs_ops to use and the file's size and invokes the latter. This patch doesn't introduce behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 53 ++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 42 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index e2ce6743113a..69cca0f4ccf3 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -912,14 +912,11 @@ static const struct kernfs_ops sysfs_bin_kfops_rw = { int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, const struct attribute *attr, bool is_bin, - umode_t amode, const void *ns) + umode_t mode, const void *ns) { - umode_t mode = (amode & S_IALLUGO) | S_IFREG; const struct kernfs_ops *ops; - struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; loff_t size; - int rc; if (!is_bin) { struct kobject *kobj = dir_sd->priv; @@ -956,14 +953,47 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, size = battr->size; } - sd = sysfs_new_dirent(attr->name, mode, SYSFS_KOBJ_ATTR); + sd = kernfs_create_file_ns(dir_sd, attr->name, mode, size, + ops, (void *)attr, ns); + if (IS_ERR(sd)) { + if (PTR_ERR(sd) == -EEXIST) + sysfs_warn_dup(dir_sd, attr->name); + return PTR_ERR(sd); + } + return 0; +} + +/** + * kernfs_create_file_ns - create a file + * @parent: directory to create the file in + * @name: name of the file + * @mode: mode of the file + * @size: size of the file + * @ops: kernfs operations for the file + * @priv: private data for the file + * @ns: optional namespace tag of the file + * + * Returns the created node on success, ERR_PTR() value on error. + */ +struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, + const char *name, + umode_t mode, loff_t size, + const struct kernfs_ops *ops, + void *priv, const void *ns) +{ + struct sysfs_addrm_cxt acxt; + struct sysfs_dirent *sd; + int rc; + + sd = sysfs_new_dirent(name, (mode & S_IALLUGO) | S_IFREG, + SYSFS_KOBJ_ATTR); if (!sd) - return -ENOMEM; + return ERR_PTR(-ENOMEM); sd->s_attr.ops = ops; sd->s_attr.size = size; sd->s_ns = ns; - sd->priv = (void *)attr; + sd->priv = priv; sysfs_dirent_init_lockdep(sd); /* @@ -977,13 +1007,14 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, sd->s_flags |= SYSFS_FLAG_HAS_MMAP; sysfs_addrm_start(&acxt); - rc = sysfs_add_one(&acxt, sd, dir_sd); + rc = __sysfs_add_one(&acxt, sd, parent); sysfs_addrm_finish(&acxt); - if (rc) + if (rc) { sysfs_put(sd); - - return rc; + return ERR_PTR(rc); + } + return sd; } int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, -- cgit v1.2.3 From 2d0cfbec2a95c16818960fda1dfa815fd1a62070 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:25 -0500 Subject: sysfs, kernfs: remove sysfs_add_one() sysfs_add_one() is a wrapper around __sysfs_add_one() which prints out duplicate name warning if __sysfs_add_one() fails with -EEXIST. The previous kernfs conversions moved all dup warnings to sysfs interface functions and sysfs_add_one() doesn't have any user left. Remove sysfs_add_one() and update __sysfs_add_one() to take its name. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 69cca0f4ccf3..9852450867cf 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -1007,7 +1007,7 @@ struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, sd->s_flags |= SYSFS_FLAG_HAS_MMAP; sysfs_addrm_start(&acxt); - rc = __sysfs_add_one(&acxt, sd, parent); + rc = sysfs_add_one(&acxt, sd, parent); sysfs_addrm_finish(&acxt); if (rc) { -- cgit v1.2.3 From d19b9846df64d8845be682b6318bd1aee246cf60 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:26 -0500 Subject: sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() kernfs_ops currently only supports single_open() behavior which is pretty restrictive. Add optional callbacks ->seq_{start|next|stop}() which, when implemented, are invoked for seq_file traversal. This allows full seq_file functionality for kernfs users. This currently doesn't have any user and doesn't change any behavior. v2: Refreshed on top of the updated "sysfs, kernfs: prepare read path for kernfs". Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 39 ++++++++++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 9852450867cf..74e3478d9cb4 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -146,6 +146,7 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) { struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops; /* * @of->mutex nests outside active ref and is just to ensure that @@ -155,26 +156,42 @@ static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) if (!sysfs_get_active(of->sd)) return ERR_PTR(-ENODEV); - /* - * The same behavior and code as single_open(). Returns !NULL if - * pos is at the beginning; otherwise, NULL. - */ - return NULL + !*ppos; + ops = kernfs_ops(of->sd); + if (ops->seq_start) { + return ops->seq_start(sf, ppos); + } else { + /* + * The same behavior and code as single_open(). Returns + * !NULL if pos is at the beginning; otherwise, NULL. + */ + return NULL + !*ppos; + } } static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) { - /* - * The same behavior and code as single_open(), always terminate - * after the initial read. - */ - ++*ppos; - return NULL; + struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops = kernfs_ops(of->sd); + + if (ops->seq_next) { + return ops->seq_next(sf, v, ppos); + } else { + /* + * The same behavior and code as single_open(), always + * terminate after the initial read. + */ + ++*ppos; + return NULL; + } } static void kernfs_seq_stop(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; + const struct kernfs_ops *ops = kernfs_ops(of->sd); + + if (ops->seq_stop) + ops->seq_stop(sf, v); sysfs_put_active(of->sd); mutex_unlock(&of->mutex); -- cgit v1.2.3 From 024f647117d697165aaadf3f1af1343b7000149a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:27 -0500 Subject: sysfs, kernfs: introduce kernfs_notify() Introduce kernfs interface to wake up poll(2) which takes and returns sysfs_dirents. sysfs_notify_dirent() is renamed to kernfs_notify() and sysfs_notify() is updated so that it doesn't directly grab sysfs_mutex but acquires the target sysfs_dirents using sysfs_get_dirent(). sysfs_notify_dirent() is reimplemented as a dumb inline wrapper around kernfs_notify(). This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 33 ++++++++++++++++++++++----------- 1 file changed, 22 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 74e3478d9cb4..a68cbef3a674 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -851,7 +851,13 @@ static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) return DEFAULT_POLLMASK|POLLERR|POLLPRI; } -void sysfs_notify_dirent(struct sysfs_dirent *sd) +/** + * kernfs_notify - notify a kernfs file + * @sd: file to notify + * + * Notify @sd such that poll(2) on @sd wakes up. + */ +void kernfs_notify(struct sysfs_dirent *sd) { struct sysfs_open_dirent *od; unsigned long flags; @@ -868,22 +874,27 @@ void sysfs_notify_dirent(struct sysfs_dirent *sd) spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); } -EXPORT_SYMBOL_GPL(sysfs_notify_dirent); +EXPORT_SYMBOL_GPL(kernfs_notify); void sysfs_notify(struct kobject *k, const char *dir, const char *attr) { - struct sysfs_dirent *sd = k->sd; - - mutex_lock(&sysfs_mutex); + struct sysfs_dirent *sd = k->sd, *tmp; if (sd && dir) - sd = sysfs_find_dirent(sd, dir, NULL); - if (sd && attr) - sd = sysfs_find_dirent(sd, attr, NULL); - if (sd) - sysfs_notify_dirent(sd); + sd = sysfs_get_dirent(sd, dir); + else + sysfs_get(sd); - mutex_unlock(&sysfs_mutex); + if (sd && attr) { + tmp = sysfs_get_dirent(sd, attr); + sysfs_put(sd); + sd = tmp; + } + + if (sd) { + kernfs_notify(sd); + sysfs_put(sd); + } } EXPORT_SYMBOL_GPL(sysfs_notify); -- cgit v1.2.3 From 517e64f57883bd63c5a4ab8b3d0d3ed68c55d0cf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:29 -0500 Subject: sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Currently, sysfs_dirent active_ref lockdep annotation uses attribute->[s]key as the lockdep key, which forces kernfs_create_file_ns() to assume that sysfs_dirent->priv is pointing to a struct attribute which may not be true for non-sysfs users. This patch restructures the lockdep annotation such that * kernfs_ops contains lockdep_key which is used by default for files created kernfs_create_file_ns(). * kernfs_create_file_ns_key() is introduced which takes an extra @key argument. The created file will use the specified key for active_ref lockdep annotation. If NULL is specified, lockdep for the file is disabled. * sysfs_add_file_mode_ns() is updated to use kernfs_create_file_ns_key() with the appropriate key from the attribute or NULL if ignore_lockdep is set. This makes the lockdep annotation properly contained in kernfs while allowing sysfs to cleanly keep its current behavior. This patch doesn't introduce any behavior differences. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a68cbef3a674..e4eca285b390 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -58,7 +58,7 @@ static struct sysfs_open_file *sysfs_of(struct file *file) */ static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) { - if (!sysfs_ignore_lockdep(sd)) + if (sd->s_flags & SYSFS_FLAG_LOCKDEP) lockdep_assert_held(sd); return sd->s_attr.ops; } @@ -71,7 +71,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) { struct kobject *kobj = sd->s_parent->priv; - if (!sysfs_ignore_lockdep(sd)) + if (sd->s_flags & SYSFS_FLAG_LOCKDEP) lockdep_assert_held(sd); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } @@ -942,6 +942,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, const struct attribute *attr, bool is_bin, umode_t mode, const void *ns) { + struct lock_class_key *key = NULL; const struct kernfs_ops *ops; struct sysfs_dirent *sd; loff_t size; @@ -981,8 +982,12 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, size = battr->size; } - sd = kernfs_create_file_ns(dir_sd, attr->name, mode, size, - ops, (void *)attr, ns); +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (!attr->ignore_lockdep) + key = attr->key ?: (struct lock_class_key *)&attr->skey; +#endif + sd = kernfs_create_file_ns_key(dir_sd, attr->name, mode, size, + ops, (void *)attr, ns, key); if (IS_ERR(sd)) { if (PTR_ERR(sd) == -EEXIST) sysfs_warn_dup(dir_sd, attr->name); @@ -992,7 +997,7 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, } /** - * kernfs_create_file_ns - create a file + * kernfs_create_file_ns_key - create a file * @parent: directory to create the file in * @name: name of the file * @mode: mode of the file @@ -1000,14 +1005,16 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, * @ops: kernfs operations for the file * @priv: private data for the file * @ns: optional namespace tag of the file + * @key: lockdep key for the file's active_ref, %NULL to disable lockdep * * Returns the created node on success, ERR_PTR() value on error. */ -struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, - const char *name, - umode_t mode, loff_t size, - const struct kernfs_ops *ops, - void *priv, const void *ns) +struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, + const char *name, + umode_t mode, loff_t size, + const struct kernfs_ops *ops, + void *priv, const void *ns, + struct lock_class_key *key) { struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; @@ -1022,7 +1029,13 @@ struct sysfs_dirent *kernfs_create_file_ns(struct sysfs_dirent *parent, sd->s_attr.size = size; sd->s_ns = ns; sd->priv = priv; - sysfs_dirent_init_lockdep(sd); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + if (key) { + lockdep_init_map(&sd->dep_map, "s_active", key, 0); + sd->s_flags |= SYSFS_FLAG_LOCKDEP; + } +#endif /* * sd->s_attr.ops is accesible only while holding active ref. We -- cgit v1.2.3 From ccf73cf336dc55bc52748205dee998d2fd4a8808 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:30 -0500 Subject: sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() Introduce kernfs interface for finding, getting and putting sysfs_dirents. * sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep assertion for sysfs_mutex is added. * sysfs_get_dirent_ns() is renamed to kernfs_find_and_get(). * Macro inline dancing around __sysfs_get/put() are removed and kernfs_get/put() are made proper functions implemented in fs/sysfs/dir.c. While the conversions are mostly equivalent, there's one difference - kernfs_get() doesn't return the input param as its return value. This change is intentional. While passing through the input increases writability in some areas, it is unnecessary and has been shown to cause confusion regarding how the last ref is handled. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 41 +++++++++++++++++++++++------------------ 1 file changed, 23 insertions(+), 18 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index e4eca285b390..7f0a79fa2ed8 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -881,19 +881,19 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) struct sysfs_dirent *sd = k->sd, *tmp; if (sd && dir) - sd = sysfs_get_dirent(sd, dir); + sd = kernfs_find_and_get(sd, dir); else - sysfs_get(sd); + kernfs_get(sd); if (sd && attr) { - tmp = sysfs_get_dirent(sd, attr); - sysfs_put(sd); + tmp = kernfs_find_and_get(sd, attr); + kernfs_put(sd); sd = tmp; } if (sd) { kernfs_notify(sd); - sysfs_put(sd); + kernfs_put(sd); } } EXPORT_SYMBOL_GPL(sysfs_notify); @@ -1052,7 +1052,7 @@ struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, sysfs_addrm_finish(&acxt); if (rc) { - sysfs_put(sd); + kernfs_put(sd); return ERR_PTR(rc); } return sd; @@ -1106,16 +1106,18 @@ int sysfs_add_file_to_group(struct kobject *kobj, struct sysfs_dirent *dir_sd; int error; - if (group) - dir_sd = sysfs_get_dirent(kobj->sd, group); - else - dir_sd = sysfs_get(kobj->sd); + if (group) { + dir_sd = kernfs_find_and_get(kobj->sd, group); + } else { + dir_sd = kobj->sd; + kernfs_get(dir_sd); + } if (!dir_sd) return -ENOENT; error = sysfs_add_file(dir_sd, attr, false); - sysfs_put(dir_sd); + kernfs_put(dir_sd); return error; } @@ -1135,7 +1137,7 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, struct iattr newattrs; int rc; - sd = sysfs_get_dirent(kobj->sd, attr->name); + sd = kernfs_find_and_get(kobj->sd, attr->name); if (!sd) return -ENOENT; @@ -1144,7 +1146,7 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, rc = kernfs_setattr(sd, &newattrs); - sysfs_put(sd); + kernfs_put(sd); return rc; } EXPORT_SYMBOL_GPL(sysfs_chmod_file); @@ -1185,13 +1187,16 @@ void sysfs_remove_file_from_group(struct kobject *kobj, { struct sysfs_dirent *dir_sd; - if (group) - dir_sd = sysfs_get_dirent(kobj->sd, group); - else - dir_sd = sysfs_get(kobj->sd); + if (group) { + dir_sd = kernfs_find_and_get(kobj->sd, group); + } else { + dir_sd = kobj->sd; + kernfs_get(dir_sd); + } + if (dir_sd) { kernfs_remove_by_name(dir_sd, attr->name); - sysfs_put(dir_sd); + kernfs_put(dir_sd); } } EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); -- cgit v1.2.3 From 414985ae23c031efbd6d16d484dea8b5de28b8f7 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:34 -0500 Subject: sysfs, kernfs: move file core code to fs/kernfs/file.c Move core file code to fs/kernfs/file.c. fs/sysfs/file.c now contains sysfs kernfs_ops callbacks, sysfs wrappers around kernfs interfaces, and sysfs_schedule_callback(). The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. v2: Refreshed on top of the v2 of "sysfs, kernfs: prepare read path for kernfs". v3: Refreshed on top of the v3 of "sysfs, kernfs: prepare read path for kernfs". Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 802 +------------------------------------------------------- 1 file changed, 1 insertion(+), 801 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 7f0a79fa2ed8..ac77d2be3c31 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -14,54 +14,12 @@ #include #include #include -#include -#include -#include #include #include -#include -#include #include -#include #include "sysfs.h" - -/* - * There's one sysfs_open_file for each open file and one sysfs_open_dirent - * for each sysfs_dirent with one or more open files. - * - * sysfs_dirent->s_attr.open points to sysfs_open_dirent. s_attr.open is - * protected by sysfs_open_dirent_lock. - * - * filp->private_data points to seq_file whose ->private points to - * sysfs_open_file. sysfs_open_files are chained at - * sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex. - */ -static DEFINE_SPINLOCK(sysfs_open_dirent_lock); -static DEFINE_MUTEX(sysfs_open_file_mutex); - -struct sysfs_open_dirent { - atomic_t refcnt; - atomic_t event; - wait_queue_head_t poll; - struct list_head files; /* goes through sysfs_open_file.list */ -}; - -static struct sysfs_open_file *sysfs_of(struct file *file) -{ - return ((struct seq_file *)file->private_data)->private; -} - -/* - * Determine the kernfs_ops for the given sysfs_dirent. This function must - * be called while holding an active reference. - */ -static const struct kernfs_ops *kernfs_ops(struct sysfs_dirent *sd) -{ - if (sd->s_flags & SYSFS_FLAG_LOCKDEP) - lockdep_assert_held(sd); - return sd->s_attr.ops; -} +#include "../kernfs/kernfs-internal.h" /* * Determine ktype->sysfs_ops for the given sysfs_dirent. This function @@ -143,147 +101,6 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, return battr->read(of->file, kobj, battr, buf, pos, count); } -static void *kernfs_seq_start(struct seq_file *sf, loff_t *ppos) -{ - struct sysfs_open_file *of = sf->private; - const struct kernfs_ops *ops; - - /* - * @of->mutex nests outside active ref and is just to ensure that - * the ops aren't called concurrently for the same open file. - */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) - return ERR_PTR(-ENODEV); - - ops = kernfs_ops(of->sd); - if (ops->seq_start) { - return ops->seq_start(sf, ppos); - } else { - /* - * The same behavior and code as single_open(). Returns - * !NULL if pos is at the beginning; otherwise, NULL. - */ - return NULL + !*ppos; - } -} - -static void *kernfs_seq_next(struct seq_file *sf, void *v, loff_t *ppos) -{ - struct sysfs_open_file *of = sf->private; - const struct kernfs_ops *ops = kernfs_ops(of->sd); - - if (ops->seq_next) { - return ops->seq_next(sf, v, ppos); - } else { - /* - * The same behavior and code as single_open(), always - * terminate after the initial read. - */ - ++*ppos; - return NULL; - } -} - -static void kernfs_seq_stop(struct seq_file *sf, void *v) -{ - struct sysfs_open_file *of = sf->private; - const struct kernfs_ops *ops = kernfs_ops(of->sd); - - if (ops->seq_stop) - ops->seq_stop(sf, v); - - sysfs_put_active(of->sd); - mutex_unlock(&of->mutex); -} - -static int kernfs_seq_show(struct seq_file *sf, void *v) -{ - struct sysfs_open_file *of = sf->private; - - of->event = atomic_read(&of->sd->s_attr.open->event); - - return of->sd->s_attr.ops->seq_show(sf, v); -} - -static const struct seq_operations kernfs_seq_ops = { - .start = kernfs_seq_start, - .next = kernfs_seq_next, - .stop = kernfs_seq_stop, - .show = kernfs_seq_show, -}; - -/* - * As reading a bin file can have side-effects, the exact offset and bytes - * specified in read(2) call should be passed to the read callback making - * it difficult to use seq_file. Implement simplistic custom buffering for - * bin files. - */ -static ssize_t kernfs_file_direct_read(struct sysfs_open_file *of, - char __user *user_buf, size_t count, - loff_t *ppos) -{ - ssize_t len = min_t(size_t, count, PAGE_SIZE); - const struct kernfs_ops *ops; - char *buf; - - buf = kmalloc(len, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - /* - * @of->mutex nests outside active ref and is just to ensure that - * the ops aren't called concurrently for the same open file. - */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) { - len = -ENODEV; - mutex_unlock(&of->mutex); - goto out_free; - } - - ops = kernfs_ops(of->sd); - if (ops->read) - len = ops->read(of, buf, len, *ppos); - else - len = -EINVAL; - - sysfs_put_active(of->sd); - mutex_unlock(&of->mutex); - - if (len < 0) - goto out_free; - - if (copy_to_user(user_buf, buf, len)) { - len = -EFAULT; - goto out_free; - } - - *ppos += len; - - out_free: - kfree(buf); - return len; -} - -/** - * kernfs_file_read - kernfs vfs read callback - * @file: file pointer - * @user_buf: data to write - * @count: number of bytes - * @ppos: starting offset - */ -static ssize_t kernfs_file_read(struct file *file, char __user *user_buf, - size_t count, loff_t *ppos) -{ - struct sysfs_open_file *of = sysfs_of(file); - - if (of->sd->s_flags & SYSFS_FLAG_HAS_SEQ_SHOW) - return seq_read(file, user_buf, count, ppos); - else - return kernfs_file_direct_read(of, user_buf, count, ppos); -} - /* kernfs write callback for regular sysfs files */ static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) @@ -319,67 +136,6 @@ static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, return battr->write(of->file, kobj, battr, buf, pos, count); } -/** - * kernfs_file_write - kernfs vfs write callback - * @file: file pointer - * @user_buf: data to write - * @count: number of bytes - * @ppos: starting offset - * - * Copy data in from userland and pass it to the matching kernfs write - * operation. - * - * There is no easy way for us to know if userspace is only doing a partial - * write, so we don't support them. We expect the entire buffer to come on - * the first write. Hint: if you're writing a value, first read the file, - * modify only the the value you're changing, then write entire buffer - * back. - */ -static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf, - size_t count, loff_t *ppos) -{ - struct sysfs_open_file *of = sysfs_of(file); - ssize_t len = min_t(size_t, count, PAGE_SIZE); - const struct kernfs_ops *ops; - char *buf; - - buf = kmalloc(len + 1, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - if (copy_from_user(buf, user_buf, len)) { - len = -EFAULT; - goto out_free; - } - buf[len] = '\0'; /* guarantee string termination */ - - /* - * @of->mutex nests outside active ref and is just to ensure that - * the ops aren't called concurrently for the same open file. - */ - mutex_lock(&of->mutex); - if (!sysfs_get_active(of->sd)) { - mutex_unlock(&of->mutex); - len = -ENODEV; - goto out_free; - } - - ops = kernfs_ops(of->sd); - if (ops->write) - len = ops->write(of, buf, len, *ppos); - else - len = -EINVAL; - - sysfs_put_active(of->sd); - mutex_unlock(&of->mutex); - - if (len > 0) - *ppos += len; -out_free: - kfree(buf); - return len; -} - static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, struct vm_area_struct *vma) { @@ -392,490 +148,6 @@ static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, return battr->mmap(of->file, kobj, battr, vma); } -static void kernfs_vma_open(struct vm_area_struct *vma) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - - if (!of->vm_ops) - return; - - if (!sysfs_get_active(of->sd)) - return; - - if (of->vm_ops->open) - of->vm_ops->open(vma); - - sysfs_put_active(of->sd); -} - -static int kernfs_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return VM_FAULT_SIGBUS; - - if (!sysfs_get_active(of->sd)) - return VM_FAULT_SIGBUS; - - ret = VM_FAULT_SIGBUS; - if (of->vm_ops->fault) - ret = of->vm_ops->fault(vma, vmf); - - sysfs_put_active(of->sd); - return ret; -} - -static int kernfs_vma_page_mkwrite(struct vm_area_struct *vma, - struct vm_fault *vmf) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return VM_FAULT_SIGBUS; - - if (!sysfs_get_active(of->sd)) - return VM_FAULT_SIGBUS; - - ret = 0; - if (of->vm_ops->page_mkwrite) - ret = of->vm_ops->page_mkwrite(vma, vmf); - else - file_update_time(file); - - sysfs_put_active(of->sd); - return ret; -} - -static int kernfs_vma_access(struct vm_area_struct *vma, unsigned long addr, - void *buf, int len, int write) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return -EINVAL; - - if (!sysfs_get_active(of->sd)) - return -EINVAL; - - ret = -EINVAL; - if (of->vm_ops->access) - ret = of->vm_ops->access(vma, addr, buf, len, write); - - sysfs_put_active(of->sd); - return ret; -} - -#ifdef CONFIG_NUMA -static int kernfs_vma_set_policy(struct vm_area_struct *vma, - struct mempolicy *new) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return 0; - - if (!sysfs_get_active(of->sd)) - return -EINVAL; - - ret = 0; - if (of->vm_ops->set_policy) - ret = of->vm_ops->set_policy(vma, new); - - sysfs_put_active(of->sd); - return ret; -} - -static struct mempolicy *kernfs_vma_get_policy(struct vm_area_struct *vma, - unsigned long addr) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - struct mempolicy *pol; - - if (!of->vm_ops) - return vma->vm_policy; - - if (!sysfs_get_active(of->sd)) - return vma->vm_policy; - - pol = vma->vm_policy; - if (of->vm_ops->get_policy) - pol = of->vm_ops->get_policy(vma, addr); - - sysfs_put_active(of->sd); - return pol; -} - -static int kernfs_vma_migrate(struct vm_area_struct *vma, - const nodemask_t *from, const nodemask_t *to, - unsigned long flags) -{ - struct file *file = vma->vm_file; - struct sysfs_open_file *of = sysfs_of(file); - int ret; - - if (!of->vm_ops) - return 0; - - if (!sysfs_get_active(of->sd)) - return 0; - - ret = 0; - if (of->vm_ops->migrate) - ret = of->vm_ops->migrate(vma, from, to, flags); - - sysfs_put_active(of->sd); - return ret; -} -#endif - -static const struct vm_operations_struct kernfs_vm_ops = { - .open = kernfs_vma_open, - .fault = kernfs_vma_fault, - .page_mkwrite = kernfs_vma_page_mkwrite, - .access = kernfs_vma_access, -#ifdef CONFIG_NUMA - .set_policy = kernfs_vma_set_policy, - .get_policy = kernfs_vma_get_policy, - .migrate = kernfs_vma_migrate, -#endif -}; - -static int kernfs_file_mmap(struct file *file, struct vm_area_struct *vma) -{ - struct sysfs_open_file *of = sysfs_of(file); - const struct kernfs_ops *ops; - int rc; - - mutex_lock(&of->mutex); - - rc = -ENODEV; - if (!sysfs_get_active(of->sd)) - goto out_unlock; - - ops = kernfs_ops(of->sd); - if (ops->mmap) - rc = ops->mmap(of, vma); - if (rc) - goto out_put; - - /* - * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup() - * to satisfy versions of X which crash if the mmap fails: that - * substitutes a new vm_file, and we don't then want bin_vm_ops. - */ - if (vma->vm_file != file) - goto out_put; - - rc = -EINVAL; - if (of->mmapped && of->vm_ops != vma->vm_ops) - goto out_put; - - /* - * It is not possible to successfully wrap close. - * So error if someone is trying to use close. - */ - rc = -EINVAL; - if (vma->vm_ops && vma->vm_ops->close) - goto out_put; - - rc = 0; - of->mmapped = 1; - of->vm_ops = vma->vm_ops; - vma->vm_ops = &kernfs_vm_ops; -out_put: - sysfs_put_active(of->sd); -out_unlock: - mutex_unlock(&of->mutex); - - return rc; -} - -/** - * sysfs_get_open_dirent - get or create sysfs_open_dirent - * @sd: target sysfs_dirent - * @of: sysfs_open_file for this instance of open - * - * If @sd->s_attr.open exists, increment its reference count; - * otherwise, create one. @of is chained to the files list. - * - * LOCKING: - * Kernel thread context (may sleep). - * - * RETURNS: - * 0 on success, -errno on failure. - */ -static int sysfs_get_open_dirent(struct sysfs_dirent *sd, - struct sysfs_open_file *of) -{ - struct sysfs_open_dirent *od, *new_od = NULL; - - retry: - mutex_lock(&sysfs_open_file_mutex); - spin_lock_irq(&sysfs_open_dirent_lock); - - if (!sd->s_attr.open && new_od) { - sd->s_attr.open = new_od; - new_od = NULL; - } - - od = sd->s_attr.open; - if (od) { - atomic_inc(&od->refcnt); - list_add_tail(&of->list, &od->files); - } - - spin_unlock_irq(&sysfs_open_dirent_lock); - mutex_unlock(&sysfs_open_file_mutex); - - if (od) { - kfree(new_od); - return 0; - } - - /* not there, initialize a new one and retry */ - new_od = kmalloc(sizeof(*new_od), GFP_KERNEL); - if (!new_od) - return -ENOMEM; - - atomic_set(&new_od->refcnt, 0); - atomic_set(&new_od->event, 1); - init_waitqueue_head(&new_od->poll); - INIT_LIST_HEAD(&new_od->files); - goto retry; -} - -/** - * sysfs_put_open_dirent - put sysfs_open_dirent - * @sd: target sysfs_dirent - * @of: associated sysfs_open_file - * - * Put @sd->s_attr.open and unlink @of from the files list. If - * reference count reaches zero, disassociate and free it. - * - * LOCKING: - * None. - */ -static void sysfs_put_open_dirent(struct sysfs_dirent *sd, - struct sysfs_open_file *of) -{ - struct sysfs_open_dirent *od = sd->s_attr.open; - unsigned long flags; - - mutex_lock(&sysfs_open_file_mutex); - spin_lock_irqsave(&sysfs_open_dirent_lock, flags); - - if (of) - list_del(&of->list); - - if (atomic_dec_and_test(&od->refcnt)) - sd->s_attr.open = NULL; - else - od = NULL; - - spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); - mutex_unlock(&sysfs_open_file_mutex); - - kfree(od); -} - -static int kernfs_file_open(struct inode *inode, struct file *file) -{ - struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; - const struct kernfs_ops *ops; - struct sysfs_open_file *of; - bool has_read, has_write, has_mmap; - int error = -EACCES; - - if (!sysfs_get_active(attr_sd)) - return -ENODEV; - - ops = kernfs_ops(attr_sd); - - has_read = ops->seq_show || ops->read || ops->mmap; - has_write = ops->write || ops->mmap; - has_mmap = ops->mmap; - - /* check perms and supported operations */ - if ((file->f_mode & FMODE_WRITE) && - (!(inode->i_mode & S_IWUGO) || !has_write)) - goto err_out; - - if ((file->f_mode & FMODE_READ) && - (!(inode->i_mode & S_IRUGO) || !has_read)) - goto err_out; - - /* allocate a sysfs_open_file for the file */ - error = -ENOMEM; - of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL); - if (!of) - goto err_out; - - /* - * The following is done to give a different lockdep key to - * @of->mutex for files which implement mmap. This is a rather - * crude way to avoid false positive lockdep warning around - * mm->mmap_sem - mmap nests @of->mutex under mm->mmap_sem and - * reading /sys/block/sda/trace/act_mask grabs sr_mutex, under - * which mm->mmap_sem nests, while holding @of->mutex. As each - * open file has a separate mutex, it's okay as long as those don't - * happen on the same file. At this point, we can't easily give - * each file a separate locking class. Let's differentiate on - * whether the file has mmap or not for now. - */ - if (has_mmap) - mutex_init(&of->mutex); - else - mutex_init(&of->mutex); - - of->sd = attr_sd; - of->file = file; - - /* - * Always instantiate seq_file even if read access doesn't use - * seq_file or is not requested. This unifies private data access - * and readable regular files are the vast majority anyway. - */ - if (ops->seq_show) - error = seq_open(file, &kernfs_seq_ops); - else - error = seq_open(file, NULL); - if (error) - goto err_free; - - ((struct seq_file *)file->private_data)->private = of; - - /* seq_file clears PWRITE unconditionally, restore it if WRITE */ - if (file->f_mode & FMODE_WRITE) - file->f_mode |= FMODE_PWRITE; - - /* make sure we have open dirent struct */ - error = sysfs_get_open_dirent(attr_sd, of); - if (error) - goto err_close; - - /* open succeeded, put active references */ - sysfs_put_active(attr_sd); - return 0; - -err_close: - seq_release(inode, file); -err_free: - kfree(of); -err_out: - sysfs_put_active(attr_sd); - return error; -} - -static int kernfs_file_release(struct inode *inode, struct file *filp) -{ - struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata; - struct sysfs_open_file *of = sysfs_of(filp); - - sysfs_put_open_dirent(sd, of); - seq_release(inode, filp); - kfree(of); - - return 0; -} - -void sysfs_unmap_bin_file(struct sysfs_dirent *sd) -{ - struct sysfs_open_dirent *od; - struct sysfs_open_file *of; - - if (!(sd->s_flags & SYSFS_FLAG_HAS_MMAP)) - return; - - spin_lock_irq(&sysfs_open_dirent_lock); - od = sd->s_attr.open; - if (od) - atomic_inc(&od->refcnt); - spin_unlock_irq(&sysfs_open_dirent_lock); - if (!od) - return; - - mutex_lock(&sysfs_open_file_mutex); - list_for_each_entry(of, &od->files, list) { - struct inode *inode = file_inode(of->file); - unmap_mapping_range(inode->i_mapping, 0, 0, 1); - } - mutex_unlock(&sysfs_open_file_mutex); - - sysfs_put_open_dirent(sd, NULL); -} - -/* Sysfs attribute files are pollable. The idea is that you read - * the content and then you use 'poll' or 'select' to wait for - * the content to change. When the content changes (assuming the - * manager for the kobject supports notification), poll will - * return POLLERR|POLLPRI, and select will return the fd whether - * it is waiting for read, write, or exceptions. - * Once poll/select indicates that the value has changed, you - * need to close and re-open the file, or seek to 0 and read again. - * Reminder: this only works for attributes which actively support - * it, and it is not possible to test an attribute from userspace - * to see if it supports poll (Neither 'poll' nor 'select' return - * an appropriate error code). When in doubt, set a suitable timeout value. - */ -static unsigned int kernfs_file_poll(struct file *filp, poll_table *wait) -{ - struct sysfs_open_file *of = sysfs_of(filp); - struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata; - struct sysfs_open_dirent *od = attr_sd->s_attr.open; - - /* need parent for the kobj, grab both */ - if (!sysfs_get_active(attr_sd)) - goto trigger; - - poll_wait(filp, &od->poll, wait); - - sysfs_put_active(attr_sd); - - if (of->event != atomic_read(&od->event)) - goto trigger; - - return DEFAULT_POLLMASK; - - trigger: - return DEFAULT_POLLMASK|POLLERR|POLLPRI; -} - -/** - * kernfs_notify - notify a kernfs file - * @sd: file to notify - * - * Notify @sd such that poll(2) on @sd wakes up. - */ -void kernfs_notify(struct sysfs_dirent *sd) -{ - struct sysfs_open_dirent *od; - unsigned long flags; - - spin_lock_irqsave(&sysfs_open_dirent_lock, flags); - - if (!WARN_ON(sysfs_type(sd) != SYSFS_KOBJ_ATTR)) { - od = sd->s_attr.open; - if (od) { - atomic_inc(&od->event); - wake_up_interruptible(&od->poll); - } - } - - spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags); -} -EXPORT_SYMBOL_GPL(kernfs_notify); - void sysfs_notify(struct kobject *k, const char *dir, const char *attr) { struct sysfs_dirent *sd = k->sd, *tmp; @@ -898,16 +170,6 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) } EXPORT_SYMBOL_GPL(sysfs_notify); -const struct file_operations kernfs_file_operations = { - .read = kernfs_file_read, - .write = kernfs_file_write, - .llseek = generic_file_llseek, - .mmap = kernfs_file_mmap, - .open = kernfs_file_open, - .release = kernfs_file_release, - .poll = kernfs_file_poll, -}; - static const struct kernfs_ops sysfs_file_kfops_empty = { }; @@ -996,68 +258,6 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, return 0; } -/** - * kernfs_create_file_ns_key - create a file - * @parent: directory to create the file in - * @name: name of the file - * @mode: mode of the file - * @size: size of the file - * @ops: kernfs operations for the file - * @priv: private data for the file - * @ns: optional namespace tag of the file - * @key: lockdep key for the file's active_ref, %NULL to disable lockdep - * - * Returns the created node on success, ERR_PTR() value on error. - */ -struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, - const char *name, - umode_t mode, loff_t size, - const struct kernfs_ops *ops, - void *priv, const void *ns, - struct lock_class_key *key) -{ - struct sysfs_addrm_cxt acxt; - struct sysfs_dirent *sd; - int rc; - - sd = sysfs_new_dirent(name, (mode & S_IALLUGO) | S_IFREG, - SYSFS_KOBJ_ATTR); - if (!sd) - return ERR_PTR(-ENOMEM); - - sd->s_attr.ops = ops; - sd->s_attr.size = size; - sd->s_ns = ns; - sd->priv = priv; - -#ifdef CONFIG_DEBUG_LOCK_ALLOC - if (key) { - lockdep_init_map(&sd->dep_map, "s_active", key, 0); - sd->s_flags |= SYSFS_FLAG_LOCKDEP; - } -#endif - - /* - * sd->s_attr.ops is accesible only while holding active ref. We - * need to know whether some ops are implemented outside active - * ref. Cache their existence in flags. - */ - if (ops->seq_show) - sd->s_flags |= SYSFS_FLAG_HAS_SEQ_SHOW; - if (ops->mmap) - sd->s_flags |= SYSFS_FLAG_HAS_MMAP; - - sysfs_addrm_start(&acxt); - rc = sysfs_add_one(&acxt, sd, parent); - sysfs_addrm_finish(&acxt); - - if (rc) { - kernfs_put(sd); - return ERR_PTR(rc); - } - return sd; -} - int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, bool is_bin) { -- cgit v1.2.3 From 9b2db6e1894577d48f4e290381bac6e573593838 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 10 Dec 2013 09:29:17 -0500 Subject: sysfs: bail early from kernfs_file_mmap() to avoid spurious lockdep warning This is v3.14 fix for the same issue that a8b14744429f ("sysfs: give different locking key to regular and bin files") addresses for v3.13. Due to the extensive kernfs reorganization in v3.14 branch, the same fix couldn't be ported as-is. The v3.13 fix was ignored while merging it into v3.14 branch. 027a485d12e0 ("sysfs: use a separate locking class for open files depending on mmap") assigned different lockdep key to sysfs_open_file->mutex depending on whether the file implements mmap or not in an attempt to avoid spurious lockdep warning caused by merging of regular and bin file paths. While this restored some of the original behavior of using different locks (at least lockdep is concerned) for the different clases of files. The restoration wasn't full because now the lockdep key assignment depends on whether the file has mmap or not instead of whether it's a regular file or not. This means that bin files which don't implement mmap will get assigned the same lockdep class as regular files. This is problematic because file_operations for bin files still implements the mmap file operation and checking whether the sysfs file actually implements mmap happens in the file operation after grabbing @sysfs_open_file->mutex. We still end up adding locking dependency from mmap locking to sysfs_open_file->mutex to the regular file mutex which triggers spurious circular locking warning. For v3.13, a8b14744429f ("sysfs: give different locking key to regular and bin files") fixed it by giving sysfs_open_file->mutex different lockdep keys depending on whether the file is regular or bin instead of whether mmap exists or not; however, due to the way sysfs is now layered behind kernfs, this approach is no longer viable. kernfs can tell whether a sysfs node has mmap implemented or not but can't tell whether a bin file from a regular one. This patch updates kernfs such that kernfs_file_mmap() checks SYSFS_FLAG_HAS_MMAP and bail before grabbing sysfs_open_file->mutex so that it doesn't add spurious locking dependency from mmap to sysfs_open_file->mutex and changes sysfs so that it specifies kernfs_ops->mmap iff the sysfs file implements mmap. Combined, this ensures that sysfs_open_file->mutex is grabbed under mmap path iff the sysfs file actually implements mmap. As sysfs_open_file->mutex is already given a different lockdep key if mmap is implemented, this removes the spurious locking dependency. Signed-off-by: Tejun Heo Reported-by: Dave Jones Link: http://lkml.kernel.org/g/20131203184324.GA11320@redhat.com Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index ac77d2be3c31..a67d1c682fed 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -142,9 +142,6 @@ static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, struct bin_attribute *battr = of->sd->priv; struct kobject *kobj = of->sd->s_parent->priv; - if (!battr->mmap) - return -ENODEV; - return battr->mmap(of->file, kobj, battr, vma); } @@ -197,6 +194,11 @@ static const struct kernfs_ops sysfs_bin_kfops_wo = { static const struct kernfs_ops sysfs_bin_kfops_rw = { .read = sysfs_kf_bin_read, .write = sysfs_kf_bin_write, +}; + +static const struct kernfs_ops sysfs_bin_kfops_mmap = { + .read = sysfs_kf_bin_read, + .write = sysfs_kf_bin_write, .mmap = sysfs_kf_bin_mmap, }; @@ -232,7 +234,9 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, } else { struct bin_attribute *battr = (void *)attr; - if ((battr->read && battr->write) || battr->mmap) + if (battr->mmap) + ops = &sysfs_bin_kfops_mmap; + else if (battr->read && battr->write) ops = &sysfs_bin_kfops_rw; else if (battr->read) ops = &sysfs_bin_kfops_ro; -- cgit v1.2.3 From 324a56e16e44baecac3ca799fd216154145c14bf Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Dec 2013 14:11:53 -0500 Subject: kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordingly kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo Cc: Neil Brown Cc: Linus Walleij Cc: Ashutosh Dixit Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 122 ++++++++++++++++++++++++++++---------------------------- 1 file changed, 61 insertions(+), 61 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index a67d1c682fed..be1cc39035bd 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -22,15 +22,15 @@ #include "../kernfs/kernfs-internal.h" /* - * Determine ktype->sysfs_ops for the given sysfs_dirent. This function + * Determine ktype->sysfs_ops for the given kernfs_node. This function * must be called while holding an active reference. */ -static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) +static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) { - struct kobject *kobj = sd->s_parent->priv; + struct kobject *kobj = kn->s_parent->priv; - if (sd->s_flags & SYSFS_FLAG_LOCKDEP) - lockdep_assert_held(sd); + if (kn->s_flags & SYSFS_FLAG_LOCKDEP) + lockdep_assert_held(kn); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } @@ -42,8 +42,8 @@ static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd) static int sysfs_kf_seq_show(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; - struct kobject *kobj = of->sd->s_parent->priv; - const struct sysfs_ops *ops = sysfs_file_ops(of->sd); + struct kobject *kobj = of->kn->s_parent->priv; + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); ssize_t count; char *buf; @@ -59,7 +59,7 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) * if @ops->show() isn't implemented. */ if (ops->show) { - count = ops->show(kobj, of->sd->priv, buf); + count = ops->show(kobj, of->kn->priv, buf); if (count < 0) return count; } @@ -81,8 +81,8 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { - struct bin_attribute *battr = of->sd->priv; - struct kobject *kobj = of->sd->s_parent->priv; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->s_parent->priv; loff_t size = file_inode(of->file)->i_size; if (!count) @@ -105,21 +105,21 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { - const struct sysfs_ops *ops = sysfs_file_ops(of->sd); - struct kobject *kobj = of->sd->s_parent->priv; + const struct sysfs_ops *ops = sysfs_file_ops(of->kn); + struct kobject *kobj = of->kn->s_parent->priv; if (!count) return 0; - return ops->store(kobj, of->sd->priv, buf, count); + return ops->store(kobj, of->kn->priv, buf, count); } /* kernfs write callback for bin sysfs files */ static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { - struct bin_attribute *battr = of->sd->priv; - struct kobject *kobj = of->sd->s_parent->priv; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->s_parent->priv; loff_t size = file_inode(of->file)->i_size; if (size) { @@ -139,30 +139,30 @@ static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, struct vm_area_struct *vma) { - struct bin_attribute *battr = of->sd->priv; - struct kobject *kobj = of->sd->s_parent->priv; + struct bin_attribute *battr = of->kn->priv; + struct kobject *kobj = of->kn->s_parent->priv; return battr->mmap(of->file, kobj, battr, vma); } -void sysfs_notify(struct kobject *k, const char *dir, const char *attr) +void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr) { - struct sysfs_dirent *sd = k->sd, *tmp; + struct kernfs_node *kn = kobj->sd, *tmp; - if (sd && dir) - sd = kernfs_find_and_get(sd, dir); + if (kn && dir) + kn = kernfs_find_and_get(kn, dir); else - kernfs_get(sd); + kernfs_get(kn); - if (sd && attr) { - tmp = kernfs_find_and_get(sd, attr); - kernfs_put(sd); - sd = tmp; + if (kn && attr) { + tmp = kernfs_find_and_get(kn, attr); + kernfs_put(kn); + kn = tmp; } - if (sd) { - kernfs_notify(sd); - kernfs_put(sd); + if (kn) { + kernfs_notify(kn); + kernfs_put(kn); } } EXPORT_SYMBOL_GPL(sysfs_notify); @@ -202,17 +202,17 @@ static const struct kernfs_ops sysfs_bin_kfops_mmap = { .mmap = sysfs_kf_bin_mmap, }; -int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, +int sysfs_add_file_mode_ns(struct kernfs_node *parent, const struct attribute *attr, bool is_bin, umode_t mode, const void *ns) { struct lock_class_key *key = NULL; const struct kernfs_ops *ops; - struct sysfs_dirent *sd; + struct kernfs_node *kn; loff_t size; if (!is_bin) { - struct kobject *kobj = dir_sd->priv; + struct kobject *kobj = parent->priv; const struct sysfs_ops *sysfs_ops = kobj->ktype->sysfs_ops; /* every kobject with an attribute needs a ktype assigned */ @@ -252,20 +252,20 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, if (!attr->ignore_lockdep) key = attr->key ?: (struct lock_class_key *)&attr->skey; #endif - sd = kernfs_create_file_ns_key(dir_sd, attr->name, mode, size, + kn = kernfs_create_file_ns_key(parent, attr->name, mode, size, ops, (void *)attr, ns, key); - if (IS_ERR(sd)) { - if (PTR_ERR(sd) == -EEXIST) - sysfs_warn_dup(dir_sd, attr->name); - return PTR_ERR(sd); + if (IS_ERR(kn)) { + if (PTR_ERR(kn) == -EEXIST) + sysfs_warn_dup(parent, attr->name); + return PTR_ERR(kn); } return 0; } -int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, +int sysfs_add_file(struct kernfs_node *parent, const struct attribute *attr, bool is_bin) { - return sysfs_add_file_mode_ns(dir_sd, attr, is_bin, attr->mode, NULL); + return sysfs_add_file_mode_ns(parent, attr, is_bin, attr->mode, NULL); } /** @@ -307,21 +307,21 @@ EXPORT_SYMBOL_GPL(sysfs_create_files); int sysfs_add_file_to_group(struct kobject *kobj, const struct attribute *attr, const char *group) { - struct sysfs_dirent *dir_sd; + struct kernfs_node *parent; int error; if (group) { - dir_sd = kernfs_find_and_get(kobj->sd, group); + parent = kernfs_find_and_get(kobj->sd, group); } else { - dir_sd = kobj->sd; - kernfs_get(dir_sd); + parent = kobj->sd; + kernfs_get(parent); } - if (!dir_sd) + if (!parent) return -ENOENT; - error = sysfs_add_file(dir_sd, attr, false); - kernfs_put(dir_sd); + error = sysfs_add_file(parent, attr, false); + kernfs_put(parent); return error; } @@ -337,20 +337,20 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group); int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, umode_t mode) { - struct sysfs_dirent *sd; + struct kernfs_node *kn; struct iattr newattrs; int rc; - sd = kernfs_find_and_get(kobj->sd, attr->name); - if (!sd) + kn = kernfs_find_and_get(kobj->sd, attr->name); + if (!kn) return -ENOENT; - newattrs.ia_mode = (mode & S_IALLUGO) | (sd->s_mode & ~S_IALLUGO); + newattrs.ia_mode = (mode & S_IALLUGO) | (kn->s_mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE; - rc = kernfs_setattr(sd, &newattrs); + rc = kernfs_setattr(kn, &newattrs); - kernfs_put(sd); + kernfs_put(kn); return rc; } EXPORT_SYMBOL_GPL(sysfs_chmod_file); @@ -366,9 +366,9 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file); void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, const void *ns) { - struct sysfs_dirent *dir_sd = kobj->sd; + struct kernfs_node *parent = kobj->sd; - kernfs_remove_by_name_ns(dir_sd, attr->name, ns); + kernfs_remove_by_name_ns(parent, attr->name, ns); } EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); @@ -389,18 +389,18 @@ EXPORT_SYMBOL_GPL(sysfs_remove_files); void sysfs_remove_file_from_group(struct kobject *kobj, const struct attribute *attr, const char *group) { - struct sysfs_dirent *dir_sd; + struct kernfs_node *parent; if (group) { - dir_sd = kernfs_find_and_get(kobj->sd, group); + parent = kernfs_find_and_get(kobj->sd, group); } else { - dir_sd = kobj->sd; - kernfs_get(dir_sd); + parent = kobj->sd; + kernfs_get(parent); } - if (dir_sd) { - kernfs_remove_by_name(dir_sd, attr->name); - kernfs_put(dir_sd); + if (parent) { + kernfs_remove_by_name(parent, attr->name); + kernfs_put(parent); } } EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group); -- cgit v1.2.3 From adc5e8b58f4886d45f79f4ff41a09001a76a6b12 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Dec 2013 14:11:54 -0500 Subject: kernfs: drop s_ prefix from kernfs_node members kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. s_ prefix for kernfs members is used inconsistently and a misnomer now. It's not like kernfs_node is used widely across the kernel making the ability to grep for the members particularly useful. Let's just drop the prefix. This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index be1cc39035bd..887703a79065 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -27,9 +27,9 @@ */ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) { - struct kobject *kobj = kn->s_parent->priv; + struct kobject *kobj = kn->parent->priv; - if (kn->s_flags & SYSFS_FLAG_LOCKDEP) + if (kn->flags & SYSFS_FLAG_LOCKDEP) lockdep_assert_held(kn); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } @@ -42,7 +42,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) static int sysfs_kf_seq_show(struct seq_file *sf, void *v) { struct sysfs_open_file *of = sf->private; - struct kobject *kobj = of->kn->s_parent->priv; + struct kobject *kobj = of->kn->parent->priv; const struct sysfs_ops *ops = sysfs_file_ops(of->kn); ssize_t count; char *buf; @@ -82,7 +82,7 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->s_parent->priv; + struct kobject *kobj = of->kn->parent->priv; loff_t size = file_inode(of->file)->i_size; if (!count) @@ -106,7 +106,7 @@ static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { const struct sysfs_ops *ops = sysfs_file_ops(of->kn); - struct kobject *kobj = of->kn->s_parent->priv; + struct kobject *kobj = of->kn->parent->priv; if (!count) return 0; @@ -119,7 +119,7 @@ static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, size_t count, loff_t pos) { struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->s_parent->priv; + struct kobject *kobj = of->kn->parent->priv; loff_t size = file_inode(of->file)->i_size; if (size) { @@ -140,7 +140,7 @@ static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, struct vm_area_struct *vma) { struct bin_attribute *battr = of->kn->priv; - struct kobject *kobj = of->kn->s_parent->priv; + struct kobject *kobj = of->kn->parent->priv; return battr->mmap(of->file, kobj, battr, vma); } @@ -345,7 +345,7 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr, if (!kn) return -ENOENT; - newattrs.ia_mode = (mode & S_IALLUGO) | (kn->s_mode & ~S_IALLUGO); + newattrs.ia_mode = (mode & S_IALLUGO) | (kn->mode & ~S_IALLUGO); newattrs.ia_valid = ATTR_MODE; rc = kernfs_setattr(kn, &newattrs); -- cgit v1.2.3 From c525aaddc366df23eb095d58a2bdf11cce62a98b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Dec 2013 14:11:55 -0500 Subject: kernfs: s/sysfs/kernfs/ in various data structures kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_open_dirent/kernfs_open_node/ * s/sysfs_open_file/kernfs_open_file/ * s/sysfs_inode_attrs/kernfs_iattrs/ * s/sysfs_addrm_cxt/kernfs_addrm_cxt/ * s/sysfs_super_info/kernfs_super_info/ * s/sysfs_info()/kernfs_info()/ * s/sysfs_open_dirent_lock/kernfs_open_node_lock/ * s/sysfs_open_file_mutex/kernfs_open_file_mutex/ * s/sysfs_of()/kernfs_of()/ This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 887703a79065..fd104b282f81 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -41,7 +41,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) */ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) { - struct sysfs_open_file *of = sf->private; + struct kernfs_open_file *of = sf->private; struct kobject *kobj = of->kn->parent->priv; const struct sysfs_ops *ops = sysfs_file_ops(of->kn); ssize_t count; @@ -78,7 +78,7 @@ static int sysfs_kf_seq_show(struct seq_file *sf, void *v) return 0; } -static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, +static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { struct bin_attribute *battr = of->kn->priv; @@ -102,7 +102,7 @@ static ssize_t sysfs_kf_bin_read(struct sysfs_open_file *of, char *buf, } /* kernfs write callback for regular sysfs files */ -static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, +static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { const struct sysfs_ops *ops = sysfs_file_ops(of->kn); @@ -115,7 +115,7 @@ static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf, } /* kernfs write callback for bin sysfs files */ -static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, +static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf, size_t count, loff_t pos) { struct bin_attribute *battr = of->kn->priv; @@ -136,7 +136,7 @@ static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf, return battr->write(of->file, kobj, battr, buf, pos, count); } -static int sysfs_kf_bin_mmap(struct sysfs_open_file *of, +static int sysfs_kf_bin_mmap(struct kernfs_open_file *of, struct vm_area_struct *vma) { struct bin_attribute *battr = of->kn->priv; -- cgit v1.2.3 From df23fc39bce03bb26e63bea57fc5f5bf6882d74b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Dec 2013 14:11:56 -0500 Subject: kernfs: s/sysfs/kernfs/ in constants kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/SYSFS_DIR/KERNFS_DIR/ * s/SYSFS_KOBJ_ATTR/KERNFS_FILE/ * s/SYSFS_KOBJ_LINK/KERNFS_LINK/ * s/SYSFS_{TYPE_FLAGS}/KERNFS_{TYPE_FLAGS}/ * s/SYSFS_FLAG_{FLAG}/KERNFS_{FLAG}/ * s/sysfs_type()/kernfs_type()/ * s/SD_DEACTIVATED_BIAS/KN_DEACTIVATED_BIAS/ This patch is strictly rename only and doesn't introduce any functional difference. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index fd104b282f81..fe6388fbd154 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -29,7 +29,7 @@ static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn) { struct kobject *kobj = kn->parent->priv; - if (kn->flags & SYSFS_FLAG_LOCKDEP) + if (kn->flags & KERNFS_LOCKDEP) lockdep_assert_held(kn); return kobj->ktype ? kobj->ktype->sysfs_ops : NULL; } -- cgit v1.2.3 From 2063d608f5110d120db60e896ec2c70c95bb7978 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 11 Dec 2013 16:02:57 -0500 Subject: kernfs: mark static names with KERNFS_STATIC_NAME Because sysfs used struct attribute which are supposed to stay constant, sysfs didn't copy names when creating regular files. The specified string for name was supposed to stay constant. Such distinction isn't inherent for kernfs. kernfs_create_file[_ns]() should be able to take the same @name as kernfs_create_dir[_ns]() As there can be huge number of sysfs attributes, we still want to be able to use static names for sysfs attributes. This patch renames kernfs_create_file_ns_key() to __kernfs_create_file() and adds @name_is_static parameter so that the caller can explicitly indicate that @name can be used without copying. kernfs is updated to use KERNFS_STATIC_NAME to distinguish static and copied names. This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index fe6388fbd154..810cf6e613e5 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -252,8 +252,8 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent, if (!attr->ignore_lockdep) key = attr->key ?: (struct lock_class_key *)&attr->skey; #endif - kn = kernfs_create_file_ns_key(parent, attr->name, mode, size, - ops, (void *)attr, ns, key); + kn = __kernfs_create_file(parent, attr->name, mode, size, ops, + (void *)attr, ns, true, key); if (IS_ERR(kn)) { if (PTR_ERR(kn) == -EEXIST) sysfs_warn_dup(parent, attr->name); -- cgit v1.2.3 From 1ae06819c77cff1ea2833c94f8c093fe8a5c79db Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 10 Jan 2014 08:57:27 -0500 Subject: kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers Sometimes it's necessary to implement a node which wants to delete nodes including itself. This isn't straightforward because of kernfs active reference. While a file operation is in progress, an active reference is held and kernfs_remove() waits for all such references to drain before completing. For a self-deleting node, this is a deadlock as kernfs_remove() ends up waiting for an active reference that itself is sitting on top of. This currently is worked around in the sysfs layer using sysfs_schedule_callback() which makes such removals asynchronous. While it works, it's rather cumbersome and inherently breaks synchronicity of the operation - the file operation which triggered the operation may complete before the removal is finished (or even started) and the removal may fail asynchronously. If a removal operation is immmediately followed by another operation which expects the specific name to be available (e.g. removal followed by rename onto the same name), there's no way to make the latter operation reliable. The thing is there's no inherent reason for this to be asynchrnous. All that's necessary to do this synchronous is a dedicated operation which drops its own active ref and deactivates self. This patch implements kernfs_remove_self() and its wrappers in sysfs and driver core. kernfs_remove_self() is to be called from one of the file operations, drops the active ref and deactivates using __kernfs_deactivate_self(), removes the self node, and restores active ref to the dead node using __kernfs_reactivate_self() so that the ref is balanced afterwards. __kernfs_remove() is updated so that it takes an early exit if the target node is already fully removed so that the active ref restored by kernfs_remove_self() after removal doesn't confuse the deactivation path. This makes implementing self-deleting nodes very easy. The normal removal path doesn't even need to be changed to use kernfs_remove_self() for the self-deleting node. The method can invoke kernfs_remove_self() on itself before proceeding the normal removal path. kernfs_remove() invoked on the node by the normal deletion path will simply be ignored. This will replace sysfs_schedule_callback(). A subtle feature of sysfs_schedule_callback() is that it collapses multiple invocations - even if multiple removals are triggered, the removal callback is run only once. An equivalent effect can be achieved by testing the return value of kernfs_remove_self() - only the one which gets %true return value should proceed with actual deletion. All other instances of kernfs_remove_self() will wait till the enclosing kernfs operation which invoked the winning instance of kernfs_remove_self() finishes and then return %false. This trivially makes all users of kernfs_remove_self() automatically show correct synchronous behavior even when there are multiple concurrent operations - all "echo 1 > delete" instances will finish only after the whole operation is completed by one of the instances. v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing and sysfs_remove_file_self() had incorrect return type. Fix it. Reported by kbuild test bot. v3: Updated to use __kernfs_{de|re}activate_self(). Signed-off-by: Tejun Heo Cc: Alan Stern Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 810cf6e613e5..1b8b91b67fdb 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -372,6 +372,29 @@ void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, } EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); +/** + * sysfs_remove_file_self - remove an object attribute from its own method + * @kobj: object we're acting for + * @attr: attribute descriptor + * + * See kernfs_remove_self() for details. + */ +bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr) +{ + struct kernfs_node *parent = kobj->sd; + struct kernfs_node *kn; + bool ret; + + kn = kernfs_find_and_get(parent, attr->name); + if (WARN_ON_ONCE(!kn)) + return false; + + ret = kernfs_remove_self(kn); + + kernfs_put(kn); + return ret; +} + void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr) { int i; -- cgit v1.2.3 From d1ba277e79889085a2faec3b68b91ce89c63f888 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 10 Jan 2014 08:57:31 -0500 Subject: sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner() All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 92 --------------------------------------------------------- 1 file changed, 92 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 1b8b91b67fdb..28cc1acd5439 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -453,95 +453,3 @@ void sysfs_remove_bin_file(struct kobject *kobj, kernfs_remove_by_name(kobj->sd, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); - -struct sysfs_schedule_callback_struct { - struct list_head workq_list; - struct kobject *kobj; - void (*func)(void *); - void *data; - struct module *owner; - struct work_struct work; -}; - -static struct workqueue_struct *sysfs_workqueue; -static DEFINE_MUTEX(sysfs_workq_mutex); -static LIST_HEAD(sysfs_workq); -static void sysfs_schedule_callback_work(struct work_struct *work) -{ - struct sysfs_schedule_callback_struct *ss = container_of(work, - struct sysfs_schedule_callback_struct, work); - - (ss->func)(ss->data); - kobject_put(ss->kobj); - module_put(ss->owner); - mutex_lock(&sysfs_workq_mutex); - list_del(&ss->workq_list); - mutex_unlock(&sysfs_workq_mutex); - kfree(ss); -} - -/** - * sysfs_schedule_callback - helper to schedule a callback for a kobject - * @kobj: object we're acting for. - * @func: callback function to invoke later. - * @data: argument to pass to @func. - * @owner: module owning the callback code - * - * sysfs attribute methods must not unregister themselves or their parent - * kobject (which would amount to the same thing). Attempts to do so will - * deadlock, since unregistration is mutually exclusive with driver - * callbacks. - * - * Instead methods can call this routine, which will attempt to allocate - * and schedule a workqueue request to call back @func with @data as its - * argument in the workqueue's process context. @kobj will be pinned - * until @func returns. - * - * Returns 0 if the request was submitted, -ENOMEM if storage could not - * be allocated, -ENODEV if a reference to @owner isn't available, - * -EAGAIN if a callback has already been scheduled for @kobj. - */ -int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), - void *data, struct module *owner) -{ - struct sysfs_schedule_callback_struct *ss, *tmp; - - if (!try_module_get(owner)) - return -ENODEV; - - mutex_lock(&sysfs_workq_mutex); - list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list) - if (ss->kobj == kobj) { - module_put(owner); - mutex_unlock(&sysfs_workq_mutex); - return -EAGAIN; - } - mutex_unlock(&sysfs_workq_mutex); - - if (sysfs_workqueue == NULL) { - sysfs_workqueue = create_singlethread_workqueue("sysfsd"); - if (sysfs_workqueue == NULL) { - module_put(owner); - return -ENOMEM; - } - } - - ss = kmalloc(sizeof(*ss), GFP_KERNEL); - if (!ss) { - module_put(owner); - return -ENOMEM; - } - kobject_get(kobj); - ss->kobj = kobj; - ss->func = func; - ss->data = data; - ss->owner = owner; - INIT_WORK(&ss->work, sysfs_schedule_callback_work); - INIT_LIST_HEAD(&ss->workq_list); - mutex_lock(&sysfs_workq_mutex); - list_add_tail(&ss->workq_list, &sysfs_workq); - mutex_unlock(&sysfs_workq_mutex); - queue_work(sysfs_workqueue, &ss->work); - return 0; -} -EXPORT_SYMBOL_GPL(sysfs_schedule_callback); -- cgit v1.2.3 From a30f82b7ebc87cdec3ef48303278f02970086118 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 13 Jan 2014 13:51:36 -0800 Subject: Revert "sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()" This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 28cc1acd5439..1b8b91b67fdb 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -453,3 +453,95 @@ void sysfs_remove_bin_file(struct kobject *kobj, kernfs_remove_by_name(kobj->sd, attr->attr.name); } EXPORT_SYMBOL_GPL(sysfs_remove_bin_file); + +struct sysfs_schedule_callback_struct { + struct list_head workq_list; + struct kobject *kobj; + void (*func)(void *); + void *data; + struct module *owner; + struct work_struct work; +}; + +static struct workqueue_struct *sysfs_workqueue; +static DEFINE_MUTEX(sysfs_workq_mutex); +static LIST_HEAD(sysfs_workq); +static void sysfs_schedule_callback_work(struct work_struct *work) +{ + struct sysfs_schedule_callback_struct *ss = container_of(work, + struct sysfs_schedule_callback_struct, work); + + (ss->func)(ss->data); + kobject_put(ss->kobj); + module_put(ss->owner); + mutex_lock(&sysfs_workq_mutex); + list_del(&ss->workq_list); + mutex_unlock(&sysfs_workq_mutex); + kfree(ss); +} + +/** + * sysfs_schedule_callback - helper to schedule a callback for a kobject + * @kobj: object we're acting for. + * @func: callback function to invoke later. + * @data: argument to pass to @func. + * @owner: module owning the callback code + * + * sysfs attribute methods must not unregister themselves or their parent + * kobject (which would amount to the same thing). Attempts to do so will + * deadlock, since unregistration is mutually exclusive with driver + * callbacks. + * + * Instead methods can call this routine, which will attempt to allocate + * and schedule a workqueue request to call back @func with @data as its + * argument in the workqueue's process context. @kobj will be pinned + * until @func returns. + * + * Returns 0 if the request was submitted, -ENOMEM if storage could not + * be allocated, -ENODEV if a reference to @owner isn't available, + * -EAGAIN if a callback has already been scheduled for @kobj. + */ +int sysfs_schedule_callback(struct kobject *kobj, void (*func)(void *), + void *data, struct module *owner) +{ + struct sysfs_schedule_callback_struct *ss, *tmp; + + if (!try_module_get(owner)) + return -ENODEV; + + mutex_lock(&sysfs_workq_mutex); + list_for_each_entry_safe(ss, tmp, &sysfs_workq, workq_list) + if (ss->kobj == kobj) { + module_put(owner); + mutex_unlock(&sysfs_workq_mutex); + return -EAGAIN; + } + mutex_unlock(&sysfs_workq_mutex); + + if (sysfs_workqueue == NULL) { + sysfs_workqueue = create_singlethread_workqueue("sysfsd"); + if (sysfs_workqueue == NULL) { + module_put(owner); + return -ENOMEM; + } + } + + ss = kmalloc(sizeof(*ss), GFP_KERNEL); + if (!ss) { + module_put(owner); + return -ENOMEM; + } + kobject_get(kobj); + ss->kobj = kobj; + ss->func = func; + ss->data = data; + ss->owner = owner; + INIT_WORK(&ss->work, sysfs_schedule_callback_work); + INIT_LIST_HEAD(&ss->workq_list); + mutex_lock(&sysfs_workq_mutex); + list_add_tail(&ss->workq_list, &sysfs_workq); + mutex_unlock(&sysfs_workq_mutex); + queue_work(sysfs_workqueue, &ss->work); + return 0; +} +EXPORT_SYMBOL_GPL(sysfs_schedule_callback); -- cgit v1.2.3 From a9f138b0e537de55933335d580ebd38c2bc53c47 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Mon, 13 Jan 2014 14:05:13 -0800 Subject: Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappers" This reverts commit 1ae06819c77cff1ea2833c94f8c093fe8a5c79db. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo Cc: Alan Stern Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 23 ----------------------- 1 file changed, 23 deletions(-) (limited to 'fs/sysfs/file.c') diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 1b8b91b67fdb..810cf6e613e5 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -372,29 +372,6 @@ void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr, } EXPORT_SYMBOL_GPL(sysfs_remove_file_ns); -/** - * sysfs_remove_file_self - remove an object attribute from its own method - * @kobj: object we're acting for - * @attr: attribute descriptor - * - * See kernfs_remove_self() for details. - */ -bool sysfs_remove_file_self(struct kobject *kobj, const struct attribute *attr) -{ - struct kernfs_node *parent = kobj->sd; - struct kernfs_node *kn; - bool ret; - - kn = kernfs_find_and_get(parent, attr->name); - if (WARN_ON_ONCE(!kn)) - return false; - - ret = kernfs_remove_self(kn); - - kernfs_put(kn); - return ret; -} - void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr) { int i; -- cgit v1.2.3