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| author | Chris Mason <chris.mason@oracle.com> | 2008-02-20 12:07:25 -0500 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-09-25 11:04:00 -0400 |
| commit | 6e92f5e651a34f24ab31ebdf3f113c7d23a36000 (patch) | |
| tree | 57695b87c3a86c418cb4ba65de53ca809e7b5e60 /fs/btrfs/file-item.c | |
| parent | 065631f6dccea07bfad48d8981369f6d9cfd6e2b (diff) | |
| download | lwn-6e92f5e651a34f24ab31ebdf3f113c7d23a36000.tar.gz lwn-6e92f5e651a34f24ab31ebdf3f113c7d23a36000.zip | |
Btrfs: While doing checksums on bios, cache the extent_buffer mapping
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/file-item.c')
| -rw-r--r-- | fs/btrfs/file-item.c | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c index 3f0e71b0e5d9..ee25e50e7c04 100644 --- a/fs/btrfs/file-item.c +++ b/fs/btrfs/file-item.c @@ -156,6 +156,11 @@ int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans, int bio_index = 0; struct bio_vec *bvec = bio->bi_io_vec; char *data; + char *eb_map; + char *eb_token; + unsigned long map_len; + unsigned long map_start; + path = btrfs_alloc_path(); BUG_ON(!path); @@ -272,6 +277,7 @@ found: item_end = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item); item_end = (struct btrfs_csum_item *)((unsigned char *)item_end + btrfs_item_size_nr(leaf, path->slots[0])); + eb_token = NULL; next_bvec: data = kmap_atomic(bvec->bv_page, KM_IRQ0); csum_result = ~(u32)0; @@ -283,15 +289,39 @@ next_bvec: printk("csum result is 0 for inode %lu offset %Lu\n", inode->i_ino, offset); } - write_extent_buffer(leaf, &csum_result, (unsigned long)item, - BTRFS_CRC32_SIZE); + if (!eb_token || + (unsigned long)item + BTRFS_CRC32_SIZE >= map_start + map_len) { + int err; + + if (eb_token) + unmap_extent_buffer(leaf, eb_token, KM_IRQ1); + eb_token = NULL; + err = map_private_extent_buffer(leaf, (unsigned long)item, + BTRFS_CRC32_SIZE, + &eb_token, &eb_map, + &map_start, &map_len, KM_IRQ1); + if (err) + eb_token = NULL; + } + if (eb_token) { + memcpy(eb_token + ((unsigned long)item & (PAGE_CACHE_SIZE - 1)), + &csum_result, BTRFS_CRC32_SIZE); + } else { + write_extent_buffer(leaf, &csum_result, (unsigned long)item, + BTRFS_CRC32_SIZE); + } bio_index++; bvec++; if (bio_index < bio->bi_vcnt) { - item = (struct btrfs_csum_item *)((char *)item + BTRFS_CRC32_SIZE); + item = (struct btrfs_csum_item *)((char *)item + + BTRFS_CRC32_SIZE); if (item < item_end) goto next_bvec; } + if (eb_token) { + unmap_extent_buffer(leaf, eb_token, KM_IRQ1); + eb_token = NULL; + } btrfs_mark_buffer_dirty(path->nodes[0]); if (bio_index < bio->bi_vcnt) { btrfs_release_path(root, path); |