diff options
| author | Darrick J. Wong <darrick.wong@oracle.com> | 2013-04-29 15:07:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-29 15:54:33 -0700 |
| commit | 7136851117744f1d291bed6d307432699d405109 (patch) | |
| tree | 6dc7d6bef45e24ad0d3d5d1b9290a81109758172 /mm/bounce.c | |
| parent | 106c992a5ebef28193cf5958e49ceff5e4aebb04 (diff) | |
| download | linux-7136851117744f1d291bed6d307432699d405109.tar.bz2 | |
mm: make snapshotting pages for stable writes a per-bio operation
Walking a bio's page mappings has proved problematic, so create a new
bio flag to indicate that a bio's data needs to be snapshotted in order
to guarantee stable pages during writeback. Next, for the one user
(ext3/jbd) of snapshotting, hook all the places where writes can be
initiated without PG_writeback set, and set BIO_SNAP_STABLE there.
We must also flag journal "metadata" bios for stable writeout, since
file data can be written through the journal. Finally, the
MS_SNAP_STABLE mount flag (only used by ext3) is now superfluous, so get
rid of it.
[akpm@linux-foundation.org: rename _submit_bh()'s `flags' to `bio_flags', delobotomize the _submit_bh declaration]
[akpm@linux-foundation.org: teeny cleanup]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/bounce.c')
| -rw-r--r-- | mm/bounce.c | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/mm/bounce.c b/mm/bounce.c index 5f8901768602..a5c2ec3589cb 100644 --- a/mm/bounce.c +++ b/mm/bounce.c @@ -181,32 +181,13 @@ static void bounce_end_io_read_isa(struct bio *bio, int err) #ifdef CONFIG_NEED_BOUNCE_POOL static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) { - struct page *page; - struct backing_dev_info *bdi; - struct address_space *mapping; - struct bio_vec *from; - int i; - if (bio_data_dir(bio) != WRITE) return 0; if (!bdi_cap_stable_pages_required(&q->backing_dev_info)) return 0; - /* - * Based on the first page that has a valid mapping, decide whether or - * not we have to employ bounce buffering to guarantee stable pages. - */ - bio_for_each_segment(from, bio, i) { - page = from->bv_page; - mapping = page_mapping(page); - if (!mapping) - continue; - bdi = mapping->backing_dev_info; - return mapping->host->i_sb->s_flags & MS_SNAP_STABLE; - } - - return 0; + return test_bit(BIO_SNAP_STABLE, &bio->bi_flags); } #else static int must_snapshot_stable_pages(struct request_queue *q, struct bio *bio) |