et4: Get the actual length of extent From: Aneesh Kumar K.V ext4 use the extent len for encoding whether the extent is intialized or not. The helper function ext4_ext_get_actual_len should be used to get the actual length of the extent. Fix the below kernel BUG http://bugzilla.kernel.org/show_bug.cgi?id=9732 kernel BUG at fs/ext4/extents.c:1056! .... Call Trace: [] :ext4dev:ext4_ext_get_blocks+0x5ba/0x8c1 [] lock_release_holdtime+0x27/0x49 [] _spin_unlock+0x17/0x20 [] :jbd2:start_this_handle+0x4e0/0x4fe [] :ext4dev:ext4_fallocate+0x175/0x39a [] lock_release_holdtime+0x27/0x49 [] __lock_acquire+0x4e7/0xc4d [] lock_release_holdtime+0x27/0x49 [] sys_fallocate+0xe4/0x10d [] tracesys+0xd5/0xda Signed-off-by: Aneesh Kumar K.V --- fs/ext4/extents.c | 24 +++++++++++++----------- 1 files changed, 13 insertions(+), 11 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 81bce98..1e46997 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1029,7 +1029,7 @@ ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, { struct ext4_extent_idx *ix; struct ext4_extent *ex; - int depth; + int depth, ee_len; BUG_ON(path == NULL); depth = path->p_depth; @@ -1043,6 +1043,7 @@ ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, * first one in the file */ ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); while (--depth >= 0) { @@ -1052,10 +1053,10 @@ ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path, return 0; } - BUG_ON(*logical < le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)); + BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); - *logical = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1; - *phys = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - 1; + *logical = le32_to_cpu(ex->ee_block) + ee_len - 1; + *phys = ext_pblock(ex) + ee_len - 1; return 0; } @@ -1075,7 +1076,7 @@ ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent_idx *ix; struct ext4_extent *ex; ext4_fsblk_t block; - int depth; + int depth, ee_len; BUG_ON(path == NULL); depth = path->p_depth; @@ -1089,6 +1090,7 @@ ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, * first one in the file */ ex = path[depth].p_ext; + ee_len = ext4_ext_get_actual_len(ex); if (*logical < le32_to_cpu(ex->ee_block)) { BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex); while (--depth >= 0) { @@ -1100,7 +1102,7 @@ ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, return 0; } - BUG_ON(*logical < le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)); + BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len)); if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) { /* next allocated block in this leaf */ @@ -1315,7 +1317,7 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, if (ext1_ee_len + ext2_ee_len > max_len) return 0; #ifdef AGGRESSIVE_TEST - if (le16_to_cpu(ex1->ee_len) >= 4) + if (ext1_ee_len >= 4) return 0; #endif @@ -2310,7 +2312,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, - le32_to_cpu(newex.ee_block) + ext_pblock(&newex); /* number of remaining blocks in the extent */ - allocated = le16_to_cpu(newex.ee_len) - + allocated = ext4_ext_get_actual_len(&newex) - (iblock - le32_to_cpu(newex.ee_block)); goto out; } else { @@ -2426,7 +2428,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, newex.ee_len = cpu_to_le16(max_blocks); err = ext4_ext_check_overlap(inode, &newex, path); if (err) - allocated = le16_to_cpu(newex.ee_len); + allocated = ext4_ext_get_actual_len(&newex); else allocated = max_blocks; @@ -2458,7 +2460,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, * but otherwise we'd need to call it every free() */ ext4_mb_discard_inode_preallocations(inode); ext4_free_blocks(handle, inode, ext_pblock(&newex), - le16_to_cpu(newex.ee_len), 0); + ext4_ext_get_actual_len(&newex), 0); goto out2; } @@ -2467,7 +2469,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, /* previous routine could use block we allocated */ newblock = ext_pblock(&newex); - allocated = le16_to_cpu(newex.ee_len); + allocated = ext4_ext_get_actual_len(&newex); outnew: __set_bit(BH_New, &bh_result->b_state);