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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2006-09-25 23:31:26 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-09-26 08:48:48 -0700 |
| commit | 6ddab3b9ebebc88bfdd8107c64f12d7e4480c559 (patch) | |
| tree | 192edd3a85d3665bb7e44c429609a7357ba12bac /mm | |
| parent | ca5f9703dffa012cc46166e6206c5a992910e041 (diff) | |
| download | linux-6ddab3b9ebebc88bfdd8107c64f12d7e4480c559.tar.gz linux-6ddab3b9ebebc88bfdd8107c64f12d7e4480c559.tar.bz2 linux-6ddab3b9ebebc88bfdd8107c64f12d7e4480c559.zip | |
[PATCH] mm: swap write failure fixup
Currently we can silently drop data if the write to swap failed. It
usually doesn't result in data-corruption because on page-in the process
will receive SIGBUS (assuming write-failure implies read-failure).
This assumption might or might not be valid.
This patch will avoid the page being discarded after a failed write. But
will print a warning the sysadmin _should_ take to heart, if a lot of swap
space becomes un-writeable, OOM is not far off.
Tested by making the write fail 'randomly' once every 50 writes or so.
[akpm@osdl.org: printk warning fix]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_io.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/mm/page_io.c b/mm/page_io.c index 88029948d00a..d2f0a5783370 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -52,8 +52,23 @@ static int end_swap_bio_write(struct bio *bio, unsigned int bytes_done, int err) if (bio->bi_size) return 1; - if (!uptodate) + if (!uptodate) { SetPageError(page); + /* + * We failed to write the page out to swap-space. + * Re-dirty the page in order to avoid it being reclaimed. + * Also print a dire warning that things will go BAD (tm) + * very quickly. + * + * Also clear PG_reclaim to avoid rotate_reclaimable_page() + */ + set_page_dirty(page); + printk(KERN_ALERT "Write-error on swap-device (%u:%u:%Lu)\n", + imajor(bio->bi_bdev->bd_inode), + iminor(bio->bi_bdev->bd_inode), + (unsigned long long)bio->bi_sector); + ClearPageReclaim(page); + } end_page_writeback(page); bio_put(bio); return 0; @@ -70,6 +85,10 @@ static int end_swap_bio_read(struct bio *bio, unsigned int bytes_done, int err) if (!uptodate) { SetPageError(page); ClearPageUptodate(page); + printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n", + imajor(bio->bi_bdev->bd_inode), + iminor(bio->bi_bdev->bd_inode), + (unsigned long long)bio->bi_sector); } else { SetPageUptodate(page); } |