From 7136851117744f1d291bed6d307432699d405109 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 29 Apr 2013 15:07:25 -0700 Subject: 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 Cc: Andy Lutomirski Cc: Adrian Hunter Cc: Artem Bityutskiy Reviewed-by: Jan Kara Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/buffer.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'fs/buffer.c') 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); /** -- cgit