diff options
| -rw-r--r-- | fs/buffer.c | 9 | ||||
| -rw-r--r-- | fs/ext3/super.c | 1 | ||||
| -rw-r--r-- | fs/jbd/commit.c | 25 | ||||
| -rw-r--r-- | include/linux/blk_types.h | 3 | ||||
| -rw-r--r-- | include/linux/buffer_head.h | 1 | ||||
| -rw-r--r-- | include/uapi/linux/fs.h | 1 | ||||
| -rw-r--r-- | mm/bounce.c | 21 | ||||
| -rw-r--r-- | mm/page-writeback.c | 4 |
8 files changed, 34 insertions, 31 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index b4dcb34c963..71578d69b82 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); /** diff --git a/fs/ext3/super.c b/fs/ext3/super.c index fb5120a5505..3dc48cc8b6e 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -2067,7 +2067,6 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ? "journal": test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered": "writeback"); - sb->s_flags |= MS_SNAP_STABLE; return 0; diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 86b39b167c2..11bb11f48b3 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -162,8 +162,17 @@ static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, for (i = 0; i < bufs; i++) { wbuf[i]->b_end_io = end_buffer_write_sync; - /* We use-up our safety reference in submit_bh() */ - submit_bh(write_op, wbuf[i]); + /* + * Here we write back pagecache data that may be mmaped. Since + * we cannot afford to clean the page and set PageWriteback + * here due to lock ordering (page lock ranks above transaction + * start), the data can change while IO is in flight. Tell the + * block layer it should bounce the bio pages if stable data + * during write is required. + * + * We use up our safety reference in submit_bh(). + */ + _submit_bh(write_op, wbuf[i], 1 << BIO_SNAP_STABLE); } } @@ -667,7 +676,17 @@ start_journal_io: clear_buffer_dirty(bh); set_buffer_uptodate(bh); bh->b_end_io = journal_end_buffer_io_sync; - submit_bh(write_op, bh); + /* + * In data=journal mode, here we can end up + * writing pagecache data that might be + * mmapped. Since we can't afford to clean the + * page and set PageWriteback (see the comment + * near the other use of _submit_bh()), the + * data can change while the write is in + * flight. Tell the block layer to bounce the + * bio pages if stable pages are required. + */ + _submit_bh(write_op, bh, 1 << BIO_SNAP_STABLE); } cond_resched(); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index cdf11191e64..22990cf4439 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -111,12 +111,13 @@ struct bio { #define BIO_FS_INTEGRITY 9 /* fs owns integrity data, not block layer */ #define BIO_QUIET 10 /* Make BIO Quiet */ #define BIO_MAPPED_INTEGRITY 11/* integrity metadata has been remapped */ +#define BIO_SNAP_STABLE 12 /* bio data must be snapshotted during write */ /* * Flags starting here get preserved by bio_reset() - this includes * BIO_POOL_IDX() */ -#define BIO_RESET_BITS 12 +#define BIO_RESET_BITS 13 #define bio_flagged(bio, flag) ((bio)->bi_flags & (1 << (flag))) diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index 5afc4f94d11..4c16c4a88d4 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -181,6 +181,7 @@ void ll_rw_block(int, int, struct buffer_head * bh[]); int sync_dirty_buffer(struct buffer_head *bh); int __sync_dirty_buffer(struct buffer_head *bh, int rw); void write_dirty_buffer(struct buffer_head *bh, int rw); +int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags); int submit_bh(int, struct buffer_head *); void write_boundary_block(struct block_device *bdev, sector_t bblock, unsigned blocksize); diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h index c7fc1e6517c..a4ed56cf0ea 100644 --- a/include/uapi/linux/fs.h +++ b/include/uapi/linux/fs.h @@ -88,7 +88,6 @@ struct inodes_stat_t { #define MS_STRICTATIME (1<<24) /* Always perform atime updates */ /* These sb flags are internal to the kernel */ -#define MS_SNAP_STABLE (1<<27) /* Snapshot pages during writeback, if needed */ #define MS_NOSEC (1<<28) #define MS_BORN (1<<29) #define MS_ACTIVE (1<<30) diff --git a/mm/bounce.c b/mm/bounce.c index 5f890176860..a5c2ec3589c 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) diff --git a/mm/page-writeback.c b/mm/page-writeback.c index efe68148f62..4514ad7415c 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2311,10 +2311,6 @@ void wait_for_stable_page(struct page *page) if (!bdi_cap_stable_pages_required(bdi)) return; -#ifdef CONFIG_NEED_BOUNCE_POOL - if (mapping->host->i_sb->s_flags & MS_SNAP_STABLE) - return; -#endif /* CONFIG_NEED_BOUNCE_POOL */ wait_on_page_writeback(page); } |