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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c124
1 files changed, 69 insertions, 55 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7910dd8b1d3a..453e3728e657 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -81,7 +81,7 @@
#include <linux/uaccess.h>
static DEFINE_IDR(loop_index_idr);
-static DEFINE_MUTEX(loop_ctl_mutex);
+static DEFINE_MUTEX(loop_index_mutex);
static int max_part;
static int part_shift;
@@ -414,18 +414,20 @@ out_free_page:
return ret;
}
-static int lo_discard(struct loop_device *lo, struct request *rq, loff_t pos)
+static int lo_fallocate(struct loop_device *lo, struct request *rq, loff_t pos,
+ int mode)
{
/*
- * We use punch hole to reclaim the free space used by the
- * image a.k.a. discard. However we do not support discard if
- * encryption is enabled, because it may give an attacker
- * useful information.
+ * We use fallocate to manipulate the space mappings used by the image
+ * a.k.a. discard/zerorange. However we do not support this if
+ * encryption is enabled, because it may give an attacker useful
+ * information.
*/
struct file *file = lo->lo_backing_file;
- int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
int ret;
+ mode |= FALLOC_FL_KEEP_SIZE;
+
if ((!file->f_op->fallocate) || lo->lo_encrypt_key_size) {
ret = -EOPNOTSUPP;
goto out;
@@ -565,9 +567,17 @@ static int do_req_filebacked(struct loop_device *lo, struct request *rq)
switch (req_op(rq)) {
case REQ_OP_FLUSH:
return lo_req_flush(lo, rq);
- case REQ_OP_DISCARD:
case REQ_OP_WRITE_ZEROES:
- return lo_discard(lo, rq, pos);
+ /*
+ * If the caller doesn't want deallocation, call zeroout to
+ * write zeroes the range. Otherwise, punch them out.
+ */
+ return lo_fallocate(lo, rq, pos,
+ (rq->cmd_flags & REQ_NOUNMAP) ?
+ FALLOC_FL_ZERO_RANGE :
+ FALLOC_FL_PUNCH_HOLE);
+ case REQ_OP_DISCARD:
+ return lo_fallocate(lo, rq, pos, FALLOC_FL_PUNCH_HOLE);
case REQ_OP_WRITE:
if (lo->transfer)
return lo_write_transfer(lo, rq, pos);
@@ -857,7 +867,7 @@ static void loop_unprepare_queue(struct loop_device *lo)
static int loop_kthread_worker_fn(void *worker_ptr)
{
- current->flags |= PF_LESS_THROTTLE;
+ current->flags |= PF_LESS_THROTTLE | PF_MEMALLOC_NOIO;
return kthread_worker_fn(worker_ptr);
}
@@ -1018,7 +1028,7 @@ static int loop_clr_fd(struct loop_device *lo)
*/
if (atomic_read(&lo->lo_refcnt) > 1) {
lo->lo_flags |= LO_FLAGS_AUTOCLEAR;
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return 0;
}
@@ -1070,12 +1080,12 @@ static int loop_clr_fd(struct loop_device *lo)
if (!part_shift)
lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN;
loop_unprepare_queue(lo);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
/*
- * Need not hold loop_ctl_mutex to fput backing file.
- * Calling fput holding loop_ctl_mutex triggers a circular
+ * Need not hold lo_ctl_mutex to fput backing file.
+ * Calling fput holding lo_ctl_mutex triggers a circular
* lock dependency possibility warning as fput can take
- * bd_mutex which is usually taken before loop_ctl_mutex.
+ * bd_mutex which is usually taken before lo_ctl_mutex.
*/
fput(filp);
return 0;
@@ -1194,7 +1204,7 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info)
int ret;
if (lo->lo_state != Lo_bound) {
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return -ENXIO;
}
@@ -1213,10 +1223,10 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info)
lo->lo_encrypt_key_size);
}
- /* Drop loop_ctl_mutex while we call into the filesystem. */
+ /* Drop lo_ctl_mutex while we call into the filesystem. */
path = lo->lo_backing_file->f_path;
path_get(&path);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
ret = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
if (!ret) {
info->lo_device = huge_encode_dev(stat.dev);
@@ -1308,7 +1318,7 @@ loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
int err;
if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1326,7 +1336,7 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
int err;
if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1401,7 +1411,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
struct loop_device *lo = bdev->bd_disk->private_data;
int err;
- mutex_lock_nested(&loop_ctl_mutex, 1);
+ mutex_lock_nested(&lo->lo_ctl_mutex, 1);
switch (cmd) {
case LOOP_SET_FD:
err = loop_set_fd(lo, mode, bdev, arg);
@@ -1410,7 +1420,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
err = loop_change_fd(lo, bdev, arg);
break;
case LOOP_CLR_FD:
- /* loop_clr_fd would have unlocked loop_ctl_mutex on success */
+ /* loop_clr_fd would have unlocked lo_ctl_mutex on success */
err = loop_clr_fd(lo);
if (!err)
goto out_unlocked;
@@ -1423,7 +1433,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
break;
case LOOP_GET_STATUS:
err = loop_get_status_old(lo, (struct loop_info __user *) arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
+ /* loop_get_status() unlocks lo_ctl_mutex */
goto out_unlocked;
case LOOP_SET_STATUS64:
err = -EPERM;
@@ -1433,7 +1443,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
break;
case LOOP_GET_STATUS64:
err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
+ /* loop_get_status() unlocks lo_ctl_mutex */
goto out_unlocked;
case LOOP_SET_CAPACITY:
err = -EPERM;
@@ -1453,7 +1463,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
default:
err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
}
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
out_unlocked:
return err;
@@ -1570,7 +1580,7 @@ loop_get_status_compat(struct loop_device *lo,
int err;
if (!arg) {
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return -EINVAL;
}
err = loop_get_status(lo, &info64);
@@ -1587,16 +1597,16 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
switch(cmd) {
case LOOP_SET_STATUS:
- mutex_lock(&loop_ctl_mutex);
+ mutex_lock(&lo->lo_ctl_mutex);
err = loop_set_status_compat(
lo, (const struct compat_loop_info __user *) arg);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
break;
case LOOP_GET_STATUS:
- mutex_lock(&loop_ctl_mutex);
+ mutex_lock(&lo->lo_ctl_mutex);
err = loop_get_status_compat(
lo, (struct compat_loop_info __user *) arg);
- /* loop_get_status() unlocks loop_ctl_mutex */
+ /* loop_get_status() unlocks lo_ctl_mutex */
break;
case LOOP_SET_CAPACITY:
case LOOP_CLR_FD:
@@ -1605,6 +1615,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
arg = (unsigned long) compat_ptr(arg);
case LOOP_SET_FD:
case LOOP_CHANGE_FD:
+ case LOOP_SET_DIRECT_IO:
err = lo_ioctl(bdev, mode, cmd, arg);
break;
default:
@@ -1618,11 +1629,9 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
static int lo_open(struct block_device *bdev, fmode_t mode)
{
struct loop_device *lo;
- int err;
+ int err = 0;
- err = mutex_lock_killable(&loop_ctl_mutex);
- if (err)
- return err;
+ mutex_lock(&loop_index_mutex);
lo = bdev->bd_disk->private_data;
if (!lo) {
err = -ENXIO;
@@ -1631,20 +1640,18 @@ static int lo_open(struct block_device *bdev, fmode_t mode)
atomic_inc(&lo->lo_refcnt);
out:
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&loop_index_mutex);
return err;
}
-static void lo_release(struct gendisk *disk, fmode_t mode)
+static void __lo_release(struct loop_device *lo)
{
- struct loop_device *lo;
int err;
- mutex_lock(&loop_ctl_mutex);
- lo = disk->private_data;
if (atomic_dec_return(&lo->lo_refcnt))
- goto out_unlock;
+ return;
+ mutex_lock(&lo->lo_ctl_mutex);
if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
/*
* In autoclear mode, stop the loop thread
@@ -1662,8 +1669,14 @@ static void lo_release(struct gendisk *disk, fmode_t mode)
blk_mq_unfreeze_queue(lo->lo_queue);
}
-out_unlock:
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
+}
+
+static void lo_release(struct gendisk *disk, fmode_t mode)
+{
+ mutex_lock(&loop_index_mutex);
+ __lo_release(disk->private_data);
+ mutex_unlock(&loop_index_mutex);
}
static const struct block_device_operations lo_fops = {
@@ -1702,10 +1715,10 @@ static int unregister_transfer_cb(int id, void *ptr, void *data)
struct loop_device *lo = ptr;
struct loop_func_table *xfer = data;
- mutex_lock(&loop_ctl_mutex);
+ mutex_lock(&lo->lo_ctl_mutex);
if (lo->lo_encryption == xfer)
loop_release_xfer(lo);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&lo->lo_ctl_mutex);
return 0;
}
@@ -1878,6 +1891,7 @@ static int loop_add(struct loop_device **l, int i)
if (!part_shift)
disk->flags |= GENHD_FL_NO_PART_SCAN;
disk->flags |= GENHD_FL_EXT_DEVT;
+ mutex_init(&lo->lo_ctl_mutex);
atomic_set(&lo->lo_refcnt, 0);
lo->lo_number = i;
spin_lock_init(&lo->lo_lock);
@@ -1956,7 +1970,7 @@ static struct kobject *loop_probe(dev_t dev, int *part, void *data)
struct kobject *kobj;
int err;
- mutex_lock(&loop_ctl_mutex);
+ mutex_lock(&loop_index_mutex);
err = loop_lookup(&lo, MINOR(dev) >> part_shift);
if (err < 0)
err = loop_add(&lo, MINOR(dev) >> part_shift);
@@ -1964,7 +1978,7 @@ static struct kobject *loop_probe(dev_t dev, int *part, void *data)
kobj = NULL;
else
kobj = get_disk(lo->lo_disk);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&loop_index_mutex);
*part = 0;
return kobj;
@@ -1974,13 +1988,9 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
unsigned long parm)
{
struct loop_device *lo;
- int ret;
-
- ret = mutex_lock_killable(&loop_ctl_mutex);
- if (ret)
- return ret;
+ int ret = -ENOSYS;
- ret = -ENOSYS;
+ mutex_lock(&loop_index_mutex);
switch (cmd) {
case LOOP_CTL_ADD:
ret = loop_lookup(&lo, parm);
@@ -1994,15 +2004,19 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
ret = loop_lookup(&lo, parm);
if (ret < 0)
break;
+ mutex_lock(&lo->lo_ctl_mutex);
if (lo->lo_state != Lo_unbound) {
ret = -EBUSY;
+ mutex_unlock(&lo->lo_ctl_mutex);
break;
}
if (atomic_read(&lo->lo_refcnt) > 0) {
ret = -EBUSY;
+ mutex_unlock(&lo->lo_ctl_mutex);
break;
}
lo->lo_disk->private_data = NULL;
+ mutex_unlock(&lo->lo_ctl_mutex);
idr_remove(&loop_index_idr, lo->lo_number);
loop_remove(lo);
break;
@@ -2012,7 +2026,7 @@ static long loop_control_ioctl(struct file *file, unsigned int cmd,
break;
ret = loop_add(&lo, -1);
}
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&loop_index_mutex);
return ret;
}
@@ -2096,10 +2110,10 @@ static int __init loop_init(void)
THIS_MODULE, loop_probe, NULL, NULL);
/* pre-create number of devices given by config or max_loop */
- mutex_lock(&loop_ctl_mutex);
+ mutex_lock(&loop_index_mutex);
for (i = 0; i < nr; i++)
loop_add(&lo, i);
- mutex_unlock(&loop_ctl_mutex);
+ mutex_unlock(&loop_index_mutex);
printk(KERN_INFO "loop: module loaded\n");
return 0;
generated by cgit v1.2.3 (git 2.0.4) at 2024-05-28 19:06:10 +0000