diff options
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 98ebc78b21a..7e6f2c9dc7c 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -449,6 +449,10 @@ int sb_prepare_remount_readonly(struct super_block *sb) struct mount *mnt; int err = 0; + /* Racy optimization. Recheck the counter under MNT_WRITE_HOLD */ + if (atomic_long_read(&sb->s_remove_count)) + return -EBUSY; + br_write_lock(vfsmount_lock); list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) { if (!(mnt->mnt.mnt_flags & MNT_READONLY)) { @@ -460,6 +464,9 @@ int sb_prepare_remount_readonly(struct super_block *sb) } } } + if (!err && atomic_long_read(&sb->s_remove_count)) + err = -EBUSY; + if (!err) { sb->s_readonly_remount = 1; smp_wmb(); |