mm: make snapshotting pages for stable writes a per-bio operation
authorDarrick J. Wong <darrick.wong@oracle.com>
Mon, 29 Apr 2013 22:07:25 +0000 (15:07 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Mon, 29 Apr 2013 22:54:33 +0000 (15:54 -0700)
commit7136851117744f1d291bed6d307432699d405109
tree6dc7d6bef45e24ad0d3d5d1b9290a81109758172
parent106c992a5ebef28193cf5958e49ceff5e4aebb04
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>
fs/buffer.c
fs/ext3/super.c
fs/jbd/commit.c
include/linux/blk_types.h
include/linux/buffer_head.h
include/uapi/linux/fs.h
mm/bounce.c
mm/page-writeback.c