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authorYan Zheng <zheng.yan@oracle.com>2008-11-10 07:34:43 -0500
committerChris Mason <chris.mason@oracle.com>2008-11-10 07:34:43 -0500
commitff5b7ee33d82414bf4baf299c21fb703bcc89629 (patch)
tree926786cf57b375e5ef1f865427c910c3d4bdfc7a /fs/btrfs
parentf2b1c41cf94d7f839fe9ede5f3ead92698a93fb3 (diff)
downloadop-kernel-dev-ff5b7ee33d82414bf4baf299c21fb703bcc89629.zip
op-kernel-dev-ff5b7ee33d82414bf4baf299c21fb703bcc89629.tar.gz
Btrfs: Fix csum error for compressed data
The decompress code doesn't take the logical offset in extent pointer into account. If the logical offset isn't zero, data will be decompressed into wrong pages. The solution used here is to record the starting offset of the extent in the file separately from the logical start of the extent_map struct. This allows us to avoid problems inserting overlapping extents. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/compression.c6
-rw-r--r--fs/btrfs/extent_map.h1
-rw-r--r--fs/btrfs/file.c2
-rw-r--r--fs/btrfs/inode.c3
4 files changed, 8 insertions, 4 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 7397c62..8e7a78a 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -505,7 +505,6 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
struct block_device *bdev;
struct bio *comp_bio;
u64 cur_disk_byte = (u64)bio->bi_sector << 9;
- u64 em_len;
struct extent_map *em;
int ret;
@@ -524,9 +523,8 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
cb->errors = 0;
cb->inode = inode;
- cb->start = em->start;
+ cb->start = em->orig_start;
compressed_len = em->block_len;
- em_len = em->len;
free_extent_map(em);
cb->len = uncompressed_len;
@@ -545,7 +543,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
}
cb->nr_pages = nr_pages;
- add_ra_bio_pages(inode, cb->start + em_len, cb);
+ add_ra_bio_pages(inode, em->start + em->len, cb);
if (!btrfs_test_opt(root, NODATASUM) &&
!btrfs_test_flag(inode, NODATASUM)) {
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index accfeda..fb6eeef 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -20,6 +20,7 @@ struct extent_map {
/* all of these are in bytes */
u64 start;
u64 len;
+ u64 orig_start;
u64 block_start;
u64 block_len;
unsigned long flags;
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 337221e..85841c5 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -222,6 +222,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
em->start < start) {
split->start = em->start;
split->len = start - em->start;
+ split->orig_start = em->orig_start;
split->block_start = em->block_start;
if (compressed)
@@ -243,6 +244,7 @@ int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
split->start = start + len;
split->len = em->start + em->len - (start + len);
+ split->orig_start = em->orig_start;
split->bdev = em->bdev;
split->flags = flags;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index e01c0d0..5966029 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3949,6 +3949,8 @@ again:
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
em->start = extent_start;
em->len = extent_end - extent_start;
+ em->orig_start = extent_start -
+ btrfs_file_extent_offset(leaf, item);
bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
if (bytenr == 0) {
em->block_start = EXTENT_MAP_HOLE;
@@ -3988,6 +3990,7 @@ again:
em->start = extent_start + extent_offset;
em->len = (copy_size + root->sectorsize - 1) &
~((u64)root->sectorsize - 1);
+ em->orig_start = EXTENT_MAP_INLINE;
if (compressed)
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
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