diff options
| -rw-r--r-- | fs/super.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/fs/super.c b/fs/super.c index aff046b0fe7..903896ec7c7 100644 --- a/fs/super.c +++ b/fs/super.c @@ -568,7 +568,7 @@ out: int do_remount_sb(struct super_block *sb, int flags, void *data, int force) { int retval; - int remount_rw; + int remount_rw, remount_ro; if (sb->s_frozen != SB_UNFROZEN) return -EBUSY; @@ -583,9 +583,12 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) shrink_dcache_sb(sb); sync_filesystem(sb); + remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); + remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY); + /* If we are remounting RDONLY and current sb is read/write, make sure there are no rw files opened */ - if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) { + if (remount_ro) { if (force) mark_files_ro(sb); else if (!fs_may_remount_ro(sb)) @@ -594,7 +597,6 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) if (retval < 0 && retval != -ENOSYS) return -EBUSY; } - remount_rw = !(flags & MS_RDONLY) && (sb->s_flags & MS_RDONLY); if (sb->s_op->remount_fs) { retval = sb->s_op->remount_fs(sb, &flags, data); @@ -604,6 +606,16 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK); if (remount_rw) vfs_dq_quota_on_remount(sb); + /* + * Some filesystems modify their metadata via some other path than the + * bdev buffer cache (eg. use a private mapping, or directories in + * pagecache, etc). Also file data modifications go via their own + * mappings. So If we try to mount readonly then copy the filesystem + * from bdev, we could get stale data, so invalidate it to give a best + * effort at coherency. + */ + if (remount_ro && sb->s_bdev) + invalidate_bdev(sb->s_bdev); return 0; } |