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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.c | |
parent | 56f3f55cf9b604b924353ab6fcdac5fee5637ae3 (diff) | |
download | kernel_samsung_tuna-38a04e432768ec0b016f3c687b4de31ac111ae59.zip kernel_samsung_tuna-38a04e432768ec0b016f3c687b4de31ac111ae59.tar.gz kernel_samsung_tuna-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.c')
-rw-r--r-- | fs/ocfs2/alloc.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 38a42f5..5661db1 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -1765,9 +1765,9 @@ set_and_inc: * * The array index of the subtree root is passed back. */ -static int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et, - struct ocfs2_path *left, - struct ocfs2_path *right) +int ocfs2_find_subtree_root(struct ocfs2_extent_tree *et, + struct ocfs2_path *left, + struct ocfs2_path *right) { int i = 0; @@ -2872,8 +2872,8 @@ out: * This looks similar, but is subtly different to * ocfs2_find_cpos_for_left_leaf(). */ -static int ocfs2_find_cpos_for_right_leaf(struct super_block *sb, - struct ocfs2_path *path, u32 *cpos) +int ocfs2_find_cpos_for_right_leaf(struct super_block *sb, + struct ocfs2_path *path, u32 *cpos) { int i, j, ret = 0; u64 blkno; |