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| author | Tao Ma <tao.ma@oracle.com> | 2009-11-30 14:32:19 +0800 |
|---|---|---|
| committer | Joel Becker <joel.becker@oracle.com> | 2009-12-02 16:14:57 -0800 |
| commit | 38a04e432768ec0b016f3c687b4de31ac111ae59 (patch) | |
| tree | a71a01561d6a654b8daf12c51e2e909f82950573 /fs/ocfs2/alloc.h | |
| parent | 56f3f55cf9b604b924353ab6fcdac5fee5637ae3 (diff) | |
| download | linux-38a04e432768ec0b016f3c687b4de31ac111ae59.tar.bz2 | |
ocfs2: Find proper end cpos for a leaf refcount block.
ocfs2 refcount tree is stored as an extent tree while
the leaf ocfs2_refcount_rec points to a refcount block.
The following step can trip a kernel panic.
mkfs.ocfs2 -b 512 -C 1M --fs-features=refcount $DEVICE
mount -t ocfs2 $DEVICE $MNT_DIR
FILE_NAME=$RANDOM
FILE_NAME_1=$RANDOM
FILE_REF="${FILE_NAME}_ref"
FILE_REF_1="${FILE_NAME}_ref_1"
for((i=0;i<305;i++))
do
# /mnt/1048576 is a file with 1048576 sizes.
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1
done
for((i=0;i<3;i++))
do
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME
done
for((i=0;i<2;i++))
do
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1
done
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME
for((i=0;i<11;i++))
do
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME
cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1
done
reflink $MNT_DIR/$FILE_NAME $MNT_DIR/$FILE_REF
# write_f is a program which will write some bytes to a file at offset.
# write_f -f file_name -l offset -w write_bytes.
./write_f -f $MNT_DIR/$FILE_REF -l $[310*1048576] -w 4096
./write_f -f $MNT_DIR/$FILE_REF -l $[306*1048576] -w 4096
./write_f -f $MNT_DIR/$FILE_REF -l $[311*1048576] -w 4096
./write_f -f $MNT_DIR/$FILE_NAME -l $[310*1048576] -w 4096
./write_f -f $MNT_DIR/$FILE_NAME -l $[311*1048576] -w 4096
reflink $MNT_DIR/$FILE_NAME $MNT_DIR/$FILE_REF_1
./write_f -f $MNT_DIR/$FILE_NAME -l $[311*1048576] -w 4096
#kernel panic here.
The reason is that if the ocfs2_extent_rec is the last record
in a leaf extent block, the old solution fails to find the
suitable end cpos. So this patch try to walk through the b-tree,
find the next sub root and get the c_pos the next sub-tree starts
from.
btw, I have runned tristan's test case against the patched kernel
for several days and this type of kernel panic never happens again.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Diffstat (limited to 'fs/ocfs2/alloc.h')
| -rw-r--r-- | fs/ocfs2/alloc.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h index 9c122d574464..1db4359ccb90 100644 --- a/fs/ocfs2/alloc.h +++ b/fs/ocfs2/alloc.h @@ -317,4 +317,9 @@ int ocfs2_path_bh_journal_access(handle_t *handle, int ocfs2_journal_access_path(struct ocfs2_caching_info *ci, handle_t *handle, struct ocfs2_path *path); +int ocfs2_find_cpos_for_right_leaf(struct super_block *sb, + struct ocfs2_path *path, u32 *cpos); +int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et, + struct ocfs2_path *left, + struct ocfs2_path *right); #endif /* OCFS2_ALLOC_H */ |