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| author | Matthew Wilcox <matthew.r.wilcox@intel.com> | 2014-06-04 16:07:46 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-06-04 16:54:02 -0700 |
| commit | 47a191fd38ebddb1bd1510ec2bc1085c578c8868 (patch) | |
| tree | 5c65289e7195f4ecd445b2b55e8d44cfa7e7ea00 /fs/mpage.c | |
| parent | 57d998456ae8680ed446aa1993f45f4d8a9a5973 (diff) | |
| download | lwn-47a191fd38ebddb1bd1510ec2bc1085c578c8868.tar.gz lwn-47a191fd38ebddb1bd1510ec2bc1085c578c8868.zip | |
fs/block_dev.c: add bdev_read_page() and bdev_write_page()
A block device driver may choose to provide a rw_page operation. These
will be called when the filesystem is attempting to do page sized I/O to
page cache pages (ie not for direct I/O). This does preclude I/Os that
are larger than page size, so this may only be a performance gain for
some devices.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Tested-by: Dheeraj Reddy <dheeraj.reddy@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/mpage.c')
| -rw-r--r-- | fs/mpage.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/mpage.c b/fs/mpage.c index 10da0da73017..5f9ed622274f 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -269,6 +269,11 @@ do_mpage_readpage(struct bio *bio, struct page *page, unsigned nr_pages, alloc_new: if (bio == NULL) { + if (first_hole == blocks_per_page) { + if (!bdev_read_page(bdev, blocks[0] << (blkbits - 9), + page)) + goto out; + } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), min_t(int, nr_pages, bio_get_nr_vecs(bdev)), GFP_KERNEL); @@ -587,6 +592,13 @@ page_is_mapped: alloc_new: if (bio == NULL) { + if (first_unmapped == blocks_per_page) { + if (!bdev_write_page(bdev, blocks[0] << (blkbits - 9), + page, wbc)) { + clean_buffers(page, first_unmapped); + goto out; + } + } bio = mpage_alloc(bdev, blocks[0] << (blkbits - 9), bio_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH); if (bio == NULL) |