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Diffstat (limited to 'fs/super.c')
-rw-r--r--fs/super.c72
1 files changed, 41 insertions, 31 deletions
diff --git a/fs/super.c b/fs/super.c
index 34afe411cf2b..05ff6abddd3c 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -54,7 +54,7 @@ static char *sb_writers_name[SB_FREEZE_LEVELS] = {
* One thing we have to be careful of with a per-sb shrinker is that we don't
* drop the last active reference to the superblock from within the shrinker.
* If that happens we could trigger unregistering the shrinker from within the
- * shrinker path and that leads to deadlock on the shrinker_mutex. Hence we
+ * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
* take a passive reference to the superblock to avoid this from occurring.
*/
static unsigned long super_cache_scan(struct shrinker *shrink,
@@ -595,7 +595,7 @@ retry:
fc->s_fs_info = NULL;
s->s_type = fc->fs_type;
s->s_iflags |= fc->s_iflags;
- strlcpy(s->s_id, s->s_type->name, sizeof(s->s_id));
+ strscpy(s->s_id, s->s_type->name, sizeof(s->s_id));
list_add_tail(&s->s_list, &super_blocks);
hlist_add_head(&s->s_instances, &s->s_type->fs_supers);
spin_unlock(&sb_lock);
@@ -674,7 +674,7 @@ retry:
return ERR_PTR(err);
}
s->s_type = type;
- strlcpy(s->s_id, type->name, sizeof(s->s_id));
+ strscpy(s->s_id, type->name, sizeof(s->s_id));
list_add_tail(&s->s_list, &super_blocks);
hlist_add_head(&s->s_instances, &type->fs_supers);
spin_unlock(&sb_lock);
@@ -903,6 +903,7 @@ int reconfigure_super(struct fs_context *fc)
struct super_block *sb = fc->root->d_sb;
int retval;
bool remount_ro = false;
+ bool remount_rw = false;
bool force = fc->sb_flags & SB_FORCE;
if (fc->sb_flags_mask & ~MS_RMT_MASK)
@@ -920,7 +921,7 @@ int reconfigure_super(struct fs_context *fc)
bdev_read_only(sb->s_bdev))
return -EACCES;
#endif
-
+ remount_rw = !(fc->sb_flags & SB_RDONLY) && sb_rdonly(sb);
remount_ro = (fc->sb_flags & SB_RDONLY) && !sb_rdonly(sb);
}
@@ -943,13 +944,18 @@ int reconfigure_super(struct fs_context *fc)
*/
if (remount_ro) {
if (force) {
- sb->s_readonly_remount = 1;
- smp_wmb();
+ sb_start_ro_state_change(sb);
} else {
retval = sb_prepare_remount_readonly(sb);
if (retval)
return retval;
}
+ } else if (remount_rw) {
+ /*
+ * Protect filesystem's reconfigure code from writes from
+ * userspace until reconfigure finishes.
+ */
+ sb_start_ro_state_change(sb);
}
if (fc->ops->reconfigure) {
@@ -965,9 +971,7 @@ int reconfigure_super(struct fs_context *fc)
WRITE_ONCE(sb->s_flags, ((sb->s_flags & ~fc->sb_flags_mask) |
(fc->sb_flags & fc->sb_flags_mask)));
- /* Needs to be ordered wrt mnt_is_readonly() */
- smp_wmb();
- sb->s_readonly_remount = 0;
+ sb_end_ro_state_change(sb);
/*
* Some filesystems modify their metadata via some other path than the
@@ -982,7 +986,7 @@ int reconfigure_super(struct fs_context *fc)
return 0;
cancel_readonly:
- sb->s_readonly_remount = 0;
+ sb_end_ro_state_change(sb);
return retval;
}
@@ -1206,6 +1210,22 @@ int get_tree_keyed(struct fs_context *fc,
EXPORT_SYMBOL(get_tree_keyed);
#ifdef CONFIG_BLOCK
+static void fs_mark_dead(struct block_device *bdev)
+{
+ struct super_block *sb;
+
+ sb = get_super(bdev);
+ if (!sb)
+ return;
+
+ if (sb->s_op->shutdown)
+ sb->s_op->shutdown(sb);
+ drop_super(sb);
+}
+
+static const struct blk_holder_ops fs_holder_ops = {
+ .mark_dead = fs_mark_dead,
+};
static int set_bdev_super(struct super_block *s, void *data)
{
@@ -1239,16 +1259,13 @@ int get_tree_bdev(struct fs_context *fc,
{
struct block_device *bdev;
struct super_block *s;
- fmode_t mode = FMODE_READ | FMODE_EXCL;
int error = 0;
- if (!(fc->sb_flags & SB_RDONLY))
- mode |= FMODE_WRITE;
-
if (!fc->source)
return invalf(fc, "No source specified");
- bdev = blkdev_get_by_path(fc->source, mode, fc->fs_type);
+ bdev = blkdev_get_by_path(fc->source, sb_open_mode(fc->sb_flags),
+ fc->fs_type, &fs_holder_ops);
if (IS_ERR(bdev)) {
errorf(fc, "%s: Can't open blockdev", fc->source);
return PTR_ERR(bdev);
@@ -1262,7 +1279,7 @@ int get_tree_bdev(struct fs_context *fc,
if (bdev->bd_fsfreeze_count > 0) {
mutex_unlock(&bdev->bd_fsfreeze_mutex);
warnf(fc, "%pg: Can't mount, blockdev is frozen", bdev);
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fc->fs_type);
return -EBUSY;
}
@@ -1271,7 +1288,7 @@ int get_tree_bdev(struct fs_context *fc,
s = sget_fc(fc, test_bdev_super_fc, set_bdev_super_fc);
mutex_unlock(&bdev->bd_fsfreeze_mutex);
if (IS_ERR(s)) {
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fc->fs_type);
return PTR_ERR(s);
}
@@ -1280,7 +1297,7 @@ int get_tree_bdev(struct fs_context *fc,
if ((fc->sb_flags ^ s->s_flags) & SB_RDONLY) {
warnf(fc, "%pg: Can't mount, would change RO state", bdev);
deactivate_locked_super(s);
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fc->fs_type);
return -EBUSY;
}
@@ -1292,10 +1309,9 @@ int get_tree_bdev(struct fs_context *fc,
* holding an active reference.
*/
up_write(&s->s_umount);
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fc->fs_type);
down_write(&s->s_umount);
} else {
- s->s_mode = mode;
snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s",
fc->fs_type->name, s->s_id);
@@ -1327,13 +1343,10 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
{
struct block_device *bdev;
struct super_block *s;
- fmode_t mode = FMODE_READ | FMODE_EXCL;
int error = 0;
- if (!(flags & SB_RDONLY))
- mode |= FMODE_WRITE;
-
- bdev = blkdev_get_by_path(dev_name, mode, fs_type);
+ bdev = blkdev_get_by_path(dev_name, sb_open_mode(flags), fs_type,
+ &fs_holder_ops);
if (IS_ERR(bdev))
return ERR_CAST(bdev);
@@ -1369,10 +1382,9 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
* holding an active reference.
*/
up_write(&s->s_umount);
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fs_type);
down_write(&s->s_umount);
} else {
- s->s_mode = mode;
snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s",
fs_type->name, s->s_id);
@@ -1392,7 +1404,7 @@ struct dentry *mount_bdev(struct file_system_type *fs_type,
error_s:
error = PTR_ERR(s);
error_bdev:
- blkdev_put(bdev, mode);
+ blkdev_put(bdev, fs_type);
error:
return ERR_PTR(error);
}
@@ -1401,13 +1413,11 @@ EXPORT_SYMBOL(mount_bdev);
void kill_block_super(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
- fmode_t mode = sb->s_mode;
bdev->bd_super = NULL;
generic_shutdown_super(sb);
sync_blockdev(bdev);
- WARN_ON_ONCE(!(mode & FMODE_EXCL));
- blkdev_put(bdev, mode | FMODE_EXCL);
+ blkdev_put(bdev, sb->s_type);
}
EXPORT_SYMBOL(kill_block_super);
generated by cgit v1.2.3 (git 2.39.0) at 2024-07-31 15:43:59 +0300