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/inode.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 1750f790af3b..5f7e2afb3457 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -67,7 +67,7 @@ static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd) return attrs; } -int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr) +static int __kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr) { struct sysfs_inode_attrs *sd_attrs; struct iattr *iattrs; @@ -102,6 +102,23 @@ int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr) return 0; } +/** + * kernfs_setattr - set iattr on a node + * @sd: target node + * @iattr: iattr to set + * + * Returns 0 on success, -errno on failure. + */ +int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr) +{ + int ret; + + mutex_lock(&sysfs_mutex); + ret = __kernfs_setattr(sd, iattr); + mutex_unlock(&sysfs_mutex); + return ret; +} + int sysfs_setattr(struct dentry *dentry, struct iattr *iattr) { struct inode *inode = dentry->d_inode; @@ -116,7 +133,7 @@ int sysfs_setattr(struct dentry *dentry, struct iattr *iattr) if (error) goto out; - error = sysfs_sd_setattr(sd, iattr); + error = __kernfs_setattr(sd, iattr); if (error) goto out; -- 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/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 5f7e2afb3457..81cc8585b32c 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -275,7 +275,7 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_fop = &sysfs_file_operations; break; case SYSFS_KOBJ_BIN_ATTR: - bin_attr = sd->s_attr.bin_attr; + bin_attr = sd->priv; inode->i_size = bin_attr->size; inode->i_fop = &sysfs_bin_operations; break; -- 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/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 81cc8585b32c..4c463dabfc6a 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -272,12 +272,12 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) break; case SYSFS_KOBJ_ATTR: inode->i_size = PAGE_SIZE; - inode->i_fop = &sysfs_file_operations; + inode->i_fop = &kernfs_file_operations; break; case SYSFS_KOBJ_BIN_ATTR: bin_attr = sd->priv; inode->i_size = bin_attr->size; - inode->i_fop = &sysfs_bin_operations; + inode->i_fop = &kernfs_file_operations; break; case SYSFS_KOBJ_LINK: inode->i_op = &sysfs_symlink_inode_operations; -- 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/inode.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 4c463dabfc6a..037a8925f56e 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -254,8 +254,6 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) { - struct bin_attribute *bin_attr; - inode->i_private = sysfs_get(sd); inode->i_mapping->a_ops = &sysfs_aops; inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; @@ -271,12 +269,8 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_fop = &sysfs_dir_operations; break; case SYSFS_KOBJ_ATTR: - inode->i_size = PAGE_SIZE; - inode->i_fop = &kernfs_file_operations; - break; case SYSFS_KOBJ_BIN_ATTR: - bin_attr = sd->priv; - inode->i_size = bin_attr->size; + inode->i_size = sd->s_attr.size; inode->i_fop = &kernfs_file_operations; break; case SYSFS_KOBJ_LINK: -- 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/inode.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 037a8925f56e..b3c717ab3496 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -269,7 +269,6 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_fop = &sysfs_dir_operations; break; case SYSFS_KOBJ_ATTR: - case SYSFS_KOBJ_BIN_ATTR: inode->i_size = sd->s_attr.size; inode->i_fop = &kernfs_file_operations; break; -- 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/inode.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index b3c717ab3496..bfe4478f82bf 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -254,7 +254,8 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) { - inode->i_private = sysfs_get(sd); + kernfs_get(sd); + inode->i_private = sd; inode->i_mapping->a_ops = &sysfs_aops; inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; inode->i_op = &sysfs_inode_operations; @@ -321,7 +322,7 @@ void sysfs_evict_inode(struct inode *inode) truncate_inode_pages(&inode->i_data, 0); clear_inode(inode); - sysfs_put(sd); + kernfs_put(sd); } int sysfs_permission(struct inode *inode, int mask) -- cgit v1.2.3 From ffed24e22845a3da0ae01095ae3f11c8d16e889d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 28 Nov 2013 14:54:32 -0500 Subject: sysfs, kernfs: move inode code to fs/kernfs/inode.c There's nothing sysfs-specific in fs/sysfs/inode.c. Move everything in it to fs/kernfs/inode.c. The respective declarations in fs/sysfs/sysfs.h are moved to fs/kernfs/kernfs-internal.h. This is pure relocation. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/inode.c | 342 ------------------------------------------------------- 1 file changed, 342 deletions(-) delete mode 100644 fs/sysfs/inode.c (limited to 'fs/sysfs/inode.c') diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c deleted file mode 100644 index bfe4478f82bf..000000000000 --- a/fs/sysfs/inode.c +++ /dev/null @@ -1,342 +0,0 @@ -/* - * fs/sysfs/inode.c - basic sysfs inode and dentry operations - * - * Copyright (c) 2001-3 Patrick Mochel - * Copyright (c) 2007 SUSE Linux Products GmbH - * Copyright (c) 2007 Tejun Heo - * - * This file is released under the GPLv2. - * - * Please see Documentation/filesystems/sysfs.txt for more information. - */ - -#undef DEBUG - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include "sysfs.h" - -static const struct address_space_operations sysfs_aops = { - .readpage = simple_readpage, - .write_begin = simple_write_begin, - .write_end = simple_write_end, -}; - -static struct backing_dev_info sysfs_backing_dev_info = { - .name = "sysfs", - .ra_pages = 0, /* No readahead */ - .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, -}; - -static const struct inode_operations sysfs_inode_operations = { - .permission = sysfs_permission, - .setattr = sysfs_setattr, - .getattr = sysfs_getattr, - .setxattr = sysfs_setxattr, -}; - -int __init sysfs_inode_init(void) -{ - return bdi_init(&sysfs_backing_dev_info); -} - -static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd) -{ - struct sysfs_inode_attrs *attrs; - struct iattr *iattrs; - - attrs = kzalloc(sizeof(struct sysfs_inode_attrs), GFP_KERNEL); - if (!attrs) - return NULL; - iattrs = &attrs->ia_iattr; - - /* assign default attributes */ - iattrs->ia_mode = sd->s_mode; - iattrs->ia_uid = GLOBAL_ROOT_UID; - iattrs->ia_gid = GLOBAL_ROOT_GID; - iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME; - - return attrs; -} - -static int __kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr) -{ - struct sysfs_inode_attrs *sd_attrs; - struct iattr *iattrs; - unsigned int ia_valid = iattr->ia_valid; - - sd_attrs = sd->s_iattr; - - if (!sd_attrs) { - /* setting attributes for the first time, allocate now */ - sd_attrs = sysfs_init_inode_attrs(sd); - if (!sd_attrs) - return -ENOMEM; - sd->s_iattr = sd_attrs; - } - /* attributes were changed at least once in past */ - iattrs = &sd_attrs->ia_iattr; - - if (ia_valid & ATTR_UID) - iattrs->ia_uid = iattr->ia_uid; - if (ia_valid & ATTR_GID) - iattrs->ia_gid = iattr->ia_gid; - if (ia_valid & ATTR_ATIME) - iattrs->ia_atime = iattr->ia_atime; - if (ia_valid & ATTR_MTIME) - iattrs->ia_mtime = iattr->ia_mtime; - if (ia_valid & ATTR_CTIME) - iattrs->ia_ctime = iattr->ia_ctime; - if (ia_valid & ATTR_MODE) { - umode_t mode = iattr->ia_mode; - iattrs->ia_mode = sd->s_mode = mode; - } - return 0; -} - -/** - * kernfs_setattr - set iattr on a node - * @sd: target node - * @iattr: iattr to set - * - * Returns 0 on success, -errno on failure. - */ -int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr) -{ - int ret; - - mutex_lock(&sysfs_mutex); - ret = __kernfs_setattr(sd, iattr); - mutex_unlock(&sysfs_mutex); - return ret; -} - -int sysfs_setattr(struct dentry *dentry, struct iattr *iattr) -{ - struct inode *inode = dentry->d_inode; - struct sysfs_dirent *sd = dentry->d_fsdata; - int error; - - if (!sd) - return -EINVAL; - - mutex_lock(&sysfs_mutex); - error = inode_change_ok(inode, iattr); - if (error) - goto out; - - error = __kernfs_setattr(sd, iattr); - if (error) - goto out; - - /* this ignores size changes */ - setattr_copy(inode, iattr); - -out: - mutex_unlock(&sysfs_mutex); - return error; -} - -static int sysfs_sd_setsecdata(struct sysfs_dirent *sd, void **secdata, - u32 *secdata_len) -{ - struct sysfs_inode_attrs *iattrs; - void *old_secdata; - size_t old_secdata_len; - - if (!sd->s_iattr) { - sd->s_iattr = sysfs_init_inode_attrs(sd); - if (!sd->s_iattr) - return -ENOMEM; - } - - iattrs = sd->s_iattr; - old_secdata = iattrs->ia_secdata; - old_secdata_len = iattrs->ia_secdata_len; - - iattrs->ia_secdata = *secdata; - iattrs->ia_secdata_len = *secdata_len; - - *secdata = old_secdata; - *secdata_len = old_secdata_len; - return 0; -} - -int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, - size_t size, int flags) -{ - struct sysfs_dirent *sd = dentry->d_fsdata; - void *secdata; - int error; - u32 secdata_len = 0; - - if (!sd) - return -EINVAL; - - if (!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)) { - const char *suffix = name + XATTR_SECURITY_PREFIX_LEN; - error = security_inode_setsecurity(dentry->d_inode, suffix, - value, size, flags); - if (error) - goto out; - error = security_inode_getsecctx(dentry->d_inode, - &secdata, &secdata_len); - if (error) - goto out; - - mutex_lock(&sysfs_mutex); - error = sysfs_sd_setsecdata(sd, &secdata, &secdata_len); - mutex_unlock(&sysfs_mutex); - - if (secdata) - security_release_secctx(secdata, secdata_len); - } else - return -EINVAL; -out: - return error; -} - -static inline void set_default_inode_attr(struct inode *inode, umode_t mode) -{ - inode->i_mode = mode; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; -} - -static inline void set_inode_attr(struct inode *inode, struct iattr *iattr) -{ - inode->i_uid = iattr->ia_uid; - inode->i_gid = iattr->ia_gid; - inode->i_atime = iattr->ia_atime; - inode->i_mtime = iattr->ia_mtime; - inode->i_ctime = iattr->ia_ctime; -} - -static void sysfs_refresh_inode(struct sysfs_dirent *sd, struct inode *inode) -{ - struct sysfs_inode_attrs *iattrs = sd->s_iattr; - - inode->i_mode = sd->s_mode; - if (iattrs) { - /* sysfs_dirent has non-default attributes - * get them from persistent copy in sysfs_dirent - */ - set_inode_attr(inode, &iattrs->ia_iattr); - security_inode_notifysecctx(inode, - iattrs->ia_secdata, - iattrs->ia_secdata_len); - } - - if (sysfs_type(sd) == SYSFS_DIR) - set_nlink(inode, sd->s_dir.subdirs + 2); -} - -int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, - struct kstat *stat) -{ - struct sysfs_dirent *sd = dentry->d_fsdata; - struct inode *inode = dentry->d_inode; - - mutex_lock(&sysfs_mutex); - sysfs_refresh_inode(sd, inode); - mutex_unlock(&sysfs_mutex); - - generic_fillattr(inode, stat); - return 0; -} - -static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) -{ - kernfs_get(sd); - inode->i_private = sd; - inode->i_mapping->a_ops = &sysfs_aops; - inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; - inode->i_op = &sysfs_inode_operations; - - set_default_inode_attr(inode, sd->s_mode); - sysfs_refresh_inode(sd, inode); - - /* initialize inode according to type */ - switch (sysfs_type(sd)) { - case SYSFS_DIR: - inode->i_op = &sysfs_dir_inode_operations; - inode->i_fop = &sysfs_dir_operations; - break; - case SYSFS_KOBJ_ATTR: - inode->i_size = sd->s_attr.size; - inode->i_fop = &kernfs_file_operations; - break; - case SYSFS_KOBJ_LINK: - inode->i_op = &sysfs_symlink_inode_operations; - break; - default: - BUG(); - } - - unlock_new_inode(inode); -} - -/** - * sysfs_get_inode - get inode for sysfs_dirent - * @sb: super block - * @sd: sysfs_dirent to allocate inode for - * - * Get inode for @sd. If such inode doesn't exist, a new inode - * is allocated and basics are initialized. New inode is - * returned locked. - * - * LOCKING: - * Kernel thread context (may sleep). - * - * RETURNS: - * Pointer to allocated inode on success, NULL on failure. - */ -struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd) -{ - struct inode *inode; - - inode = iget_locked(sb, sd->s_ino); - if (inode && (inode->i_state & I_NEW)) - sysfs_init_inode(sd, inode); - - return inode; -} - -/* - * The sysfs_dirent serves as both an inode and a directory entry for sysfs. - * To prevent the sysfs inode numbers from being freed prematurely we take a - * reference to sysfs_dirent from the sysfs inode. A - * super_operations.evict_inode() implementation is needed to drop that - * reference upon inode destruction. - */ -void sysfs_evict_inode(struct inode *inode) -{ - struct sysfs_dirent *sd = inode->i_private; - - truncate_inode_pages(&inode->i_data, 0); - clear_inode(inode); - kernfs_put(sd); -} - -int sysfs_permission(struct inode *inode, int mask) -{ - struct sysfs_dirent *sd; - - if (mask & MAY_NOT_BLOCK) - return -ECHILD; - - sd = inode->i_private; - - mutex_lock(&sysfs_mutex); - sysfs_refresh_inode(sd, inode); - mutex_unlock(&sysfs_mutex); - - return generic_permission(inode, mask); -} -- cgit v1.2.3