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author | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-12 11:19:01 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-12 11:19:01 -0700 |
commit | e1df8b0a1bb2ac8254616d6075e40f9ca447fa29 (patch) | |
tree | d8e6f12e4d10f6da02e6639973e8c4da29f13c31 | |
parent | dfb22fc5c0eb7645f47a752ce537bfb2c8a6aea6 (diff) | |
parent | 505a666ee3fc611518e85df203eb8c707995ceaa (diff) | |
download | lwn-e1df8b0a1bb2ac8254616d6075e40f9ca447fa29.tar.gz lwn-e1df8b0a1bb2ac8254616d6075e40f9ca447fa29.zip |
Merge branch 'writeback-plugging'
Fix up the writeback plugging introduced in commit d353d7587d02
("writeback: plug writeback at a high level") that then caused problems
due to the unplug happening with a spinlock held.
* writeback-plugging:
writeback: plug writeback in wb_writeback() and writeback_inodes_wb()
Revert "writeback: plug writeback at a high level"
-rw-r--r-- | fs/fs-writeback.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 24489126f8ca..587ac08eabb6 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1380,6 +1380,10 @@ static long writeback_chunk_size(struct bdi_writeback *wb, * Write a portion of b_io inodes which belong to @sb. * * Return the number of pages and/or inodes written. + * + * NOTE! This is called with wb->list_lock held, and will + * unlock and relock that for each inode it ends up doing + * IO for. */ static long writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, @@ -1398,9 +1402,7 @@ static long writeback_sb_inodes(struct super_block *sb, unsigned long start_time = jiffies; long write_chunk; long wrote = 0; /* count both pages and inodes */ - struct blk_plug plug; - blk_start_plug(&plug); while (!list_empty(&wb->b_io)) { struct inode *inode = wb_inode(wb->b_io.prev); @@ -1498,7 +1500,6 @@ static long writeback_sb_inodes(struct super_block *sb, break; } } - blk_finish_plug(&plug); return wrote; } @@ -1545,12 +1546,15 @@ static long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages, .range_cyclic = 1, .reason = reason, }; + struct blk_plug plug; + blk_start_plug(&plug); spin_lock(&wb->list_lock); if (list_empty(&wb->b_io)) queue_io(wb, &work); __writeback_inodes_wb(wb, &work); spin_unlock(&wb->list_lock); + blk_finish_plug(&plug); return nr_pages - work.nr_pages; } @@ -1578,10 +1582,12 @@ static long wb_writeback(struct bdi_writeback *wb, unsigned long oldest_jif; struct inode *inode; long progress; + struct blk_plug plug; oldest_jif = jiffies; work->older_than_this = &oldest_jif; + blk_start_plug(&plug); spin_lock(&wb->list_lock); for (;;) { /* @@ -1661,6 +1667,7 @@ static long wb_writeback(struct bdi_writeback *wb, } } spin_unlock(&wb->list_lock); + blk_finish_plug(&plug); return nr_pages - work->nr_pages; } |