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authorDarrick J. Wong <darrick.wong@oracle.com>2013-04-29 15:07:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-04-29 15:54:33 -0700
commit7136851117744f1d291bed6d307432699d405109 (patch)
tree6dc7d6bef45e24ad0d3d5d1b9290a81109758172 /fs/buffer.c
parent106c992a5ebef28193cf5958e49ceff5e4aebb04 (diff)
downloadlwn-7136851117744f1d291bed6d307432699d405109.tar.gz
lwn-7136851117744f1d291bed6d307432699d405109.zip
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 'fs/buffer.c')
-rw-r--r--fs/buffer.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index b4dcb34c9635..71578d69b82d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2949,7 +2949,7 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
}
}
-int submit_bh(int rw, struct buffer_head * bh)
+int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
{
struct bio *bio;
int ret = 0;
@@ -2984,6 +2984,7 @@ int submit_bh(int rw, struct buffer_head * bh)
bio->bi_end_io = end_bio_bh_io_sync;
bio->bi_private = bh;
+ bio->bi_flags |= bio_flags;
/* Take care of bh's that straddle the end of the device */
guard_bh_eod(rw, bio, bh);
@@ -2997,6 +2998,12 @@ int submit_bh(int rw, struct buffer_head * bh)
bio_put(bio);
return ret;
}
+EXPORT_SYMBOL_GPL(_submit_bh);
+
+int submit_bh(int rw, struct buffer_head *bh)
+{
+ return _submit_bh(rw, bh, 0);
+}
EXPORT_SYMBOL(submit_bh);
/**