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| author | Christoph Hellwig <hch@lst.de> | 2010-06-08 18:14:51 +0200 |
|---|---|---|
| committer | Jens Axboe <jaxboe@fusionio.com> | 2010-06-11 12:58:07 +0200 |
| commit | cf37e972478ec58a8a54a6b4f951815f0ae28f78 (patch) | |
| tree | b14d75074692ddb213e22e098a64087950f4cf78 /fs/fs-writeback.c | |
| parent | 3c4d716538f3eefb1c1f10961a047a6456a2b590 (diff) | |
| download | lwn-cf37e972478ec58a8a54a6b4f951815f0ae28f78.tar.gz lwn-cf37e972478ec58a8a54a6b4f951815f0ae28f78.zip | |
writeback: enforce s_umount locking in writeback_inodes_sb
Make sure that not only sync_filesystem but all callers of writeback_inodes_sb
have the superblock protected against remount. As-is this disables all
functionality for these callers, but the next patch relies on this locking to
fix writeback_inodes_sb for sync_filesystem.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Diffstat (limited to 'fs/fs-writeback.c')
| -rw-r--r-- | fs/fs-writeback.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 759666966c6d..2627f0dfcd9c 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1180,6 +1180,8 @@ void writeback_inodes_sb(struct super_block *sb) .sync_mode = WB_SYNC_NONE, }; + WARN_ON(!rwsem_is_locked(&sb->s_umount)); + args.nr_pages = nr_dirty + nr_unstable + (inodes_stat.nr_inodes - inodes_stat.nr_unused); @@ -1197,7 +1199,9 @@ EXPORT_SYMBOL(writeback_inodes_sb); int writeback_inodes_sb_if_idle(struct super_block *sb) { if (!writeback_in_progress(sb->s_bdi)) { + down_read(&sb->s_umount); writeback_inodes_sb(sb); + up_read(&sb->s_umount); return 1; } else return 0; @@ -1220,6 +1224,8 @@ void sync_inodes_sb(struct super_block *sb) .range_cyclic = 0, }; + WARN_ON(!rwsem_is_locked(&sb->s_umount)); + bdi_queue_work_onstack(&args); wait_sb_inodes(sb); } |