From: Hu Weiwen <seh...@mail.scut.edu.cn>
When the subsequent erofs_battach() is called on an buffer block of
which (bb->buffers.off % EROFS_BLKSIZ == 0), `tail_blkaddr' won't be
updated correctly. This bug can be reproduced by:
mkdir bug-repo
head -c 4032 /dev/urandom > bug-repo/1
head -c 4095 /dev/urandom > bug-repo/2
head -c 12345 /dev/urandom > bug-repo/3 # arbitrary size
mkfs.erofs -Eforce-inode-compact bug-repo.erofs.img bug-repo
Then mount this image and see that file `3' in the image is different
from `bug-repo/3'.
This patch fix this by:
* Handle `oob' and `tail_blkaddr' for the case above properly;
* Don't inline tail-packing data for such case, since the tail-packing
data is actually in a different block from inode itself even kernel
can handle such cases properly.
Signed-off-by: Hu Weiwen <seh...@mail.scut.edu.cn>
Reviewed-by: Gao Xiang <hsiang...@aol.com>
Signed-off-by: Gao Xiang <hsiang...@aol.com>
---
changes since v2:
- update commit message;
- refine 2 asserts from < 0 to != EROFS_BLKSIZ.
lib/cache.c | 4 ++--
lib/compress.c | 3 ++-
lib/inode.c | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/lib/cache.c b/lib/cache.c
index 40d3b1f3f4d5..e3327c3f1586 100644
--- a/lib/cache.c
+++ b/lib/cache.c
@@ -102,7 +102,7 @@ static int __erofs_battach(struct erofs_buffer_block *bb,
bool dryrun)
{
const erofs_off_t alignedoffset = roundup(bb->buffers.off, alignsize);
- const int oob = cmpsgn(roundup(bb->buffers.off % EROFS_BLKSIZ,
+ const int oob = cmpsgn(roundup((bb->buffers.off - 1) % EROFS_BLKSIZ + 1,
alignsize) + incr + extrasize,
EROFS_BLKSIZ);
bool tailupdate = false;
@@ -134,7 +134,7 @@ static int __erofs_battach(struct erofs_buffer_block *bb,
tail_blkaddr = blkaddr + BLK_ROUND_UP(bb->buffers.off);
erofs_bupdate_mapped(bb);
}
- return (alignedoffset + incr) % EROFS_BLKSIZ;
+ return (alignedoffset + incr - 1) % EROFS_BLKSIZ + 1;
}
int erofs_bh_balloon(struct erofs_buffer_head *bh, erofs_off_t incr)
diff --git a/lib/compress.c b/lib/compress.c
index 2b1f93c389ff..4b685cd27080 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -456,8 +456,9 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
vle_write_indexes_final(&ctx);
close(fd);
+ DBG_BUGON(!compressed_blocks);
ret = erofs_bh_balloon(bh, blknr_to_addr(compressed_blocks));
- DBG_BUGON(ret);
+ DBG_BUGON(ret != EROFS_BLKSIZ);
erofs_info("compressed %s (%llu bytes) into %u blocks",
inode->i_srcpath, (unsigned long long)inode->i_size,
diff --git a/lib/inode.c b/lib/inode.c
index 6371aa563673..40189fed37dd 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -531,7 +531,7 @@ int erofs_prepare_tail_block(struct erofs_inode *inode)
}
/* expend a block as the tail block (should be successful) */
ret = erofs_bh_balloon(bh, EROFS_BLKSIZ);
- DBG_BUGON(ret);
+ DBG_BUGON(ret != EROFS_BLKSIZ);
return 0;
}
--
2.24.0
