diff options
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 69 |
1 files changed, 51 insertions, 18 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index fb9b41483c86..214e68a5e79f 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2359,7 +2359,7 @@ int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) static int ext4_remove_blocks(handle_t *handle, struct inode *inode, struct ext4_extent *ex, - ext4_fsblk_t *partial_cluster, + long long *partial_cluster, ext4_lblk_t from, ext4_lblk_t to) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); @@ -2388,7 +2388,8 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, * partial cluster here. */ pblk = ext4_ext_pblock(ex) + ee_len - 1; - if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) { + if ((*partial_cluster > 0) && + (EXT4_B2C(sbi, pblk) != *partial_cluster)) { ext4_free_blocks(handle, inode, NULL, EXT4_C2B(sbi, *partial_cluster), sbi->s_cluster_ratio, flags); @@ -2414,23 +2415,41 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, && to == le32_to_cpu(ex->ee_block) + ee_len - 1) { /* tail removal */ ext4_lblk_t num; + unsigned int unaligned; num = le32_to_cpu(ex->ee_block) + ee_len - from; pblk = ext4_ext_pblock(ex) + ee_len - num; - ext_debug("free last %u blocks starting %llu\n", num, pblk); + /* + * Usually we want to free partial cluster at the end of the + * extent, except for the situation when the cluster is still + * used by any other extent (partial_cluster is negative). + */ + if (*partial_cluster < 0 && + -(*partial_cluster) == EXT4_B2C(sbi, pblk + num - 1)) + flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER; + + ext_debug("free last %u blocks starting %llu partial %lld\n", + num, pblk, *partial_cluster); ext4_free_blocks(handle, inode, NULL, pblk, num, flags); /* * If the block range to be freed didn't start at the * beginning of a cluster, and we removed the entire - * extent, save the partial cluster here, since we - * might need to delete if we determine that the - * truncate operation has removed all of the blocks in - * the cluster. + * extent and the cluster is not used by any other extent, + * save the partial cluster here, since we might need to + * delete if we determine that the truncate operation has + * removed all of the blocks in the cluster. + * + * On the other hand, if we did not manage to free the whole + * extent, we have to mark the cluster as used (store negative + * cluster number in partial_cluster). */ - if (pblk & (sbi->s_cluster_ratio - 1) && - (ee_len == num)) + unaligned = pblk & (sbi->s_cluster_ratio - 1); + if (unaligned && (ee_len == num) && + (*partial_cluster != -((long long)EXT4_B2C(sbi, pblk)))) *partial_cluster = EXT4_B2C(sbi, pblk); - else + else if (unaligned) + *partial_cluster = -((long long)EXT4_B2C(sbi, pblk)); + else if (*partial_cluster > 0) *partial_cluster = 0; } else ext4_error(sbi->s_sb, "strange request: removal(2) " @@ -2448,12 +2467,16 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, * @handle: The journal handle * @inode: The files inode * @path: The path to the leaf + * @partial_cluster: The cluster which we'll have to free if all extents + * has been released from it. It gets negative in case + * that the cluster is still used. * @start: The first block to remove * @end: The last block to remove */ static int ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, - struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster, + struct ext4_ext_path *path, + long long *partial_cluster, ext4_lblk_t start, ext4_lblk_t end) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); @@ -2466,6 +2489,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, unsigned short ex_ee_len; unsigned uninitialized = 0; struct ext4_extent *ex; + ext4_fsblk_t pblk; /* the header must be checked already in ext4_ext_remove_space() */ ext_debug("truncate since %u in leaf to %u\n", start, end); @@ -2504,6 +2528,16 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, /* If this extent is beyond the end of the hole, skip it */ if (end < ex_ee_block) { + /* + * We're going to skip this extent and move to another, + * so if this extent is not cluster aligned we have + * to mark the current cluster as used to avoid + * accidentally freeing it later on + */ + pblk = ext4_ext_pblock(ex); + if (pblk & (sbi->s_cluster_ratio - 1)) + *partial_cluster = + -((long long)EXT4_B2C(sbi, pblk)); ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); @@ -2579,7 +2613,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, sizeof(struct ext4_extent)); } le16_add_cpu(&eh->eh_entries, -1); - } else + } else if (*partial_cluster > 0) *partial_cluster = 0; err = ext4_ext_dirty(handle, inode, path + depth); @@ -2597,11 +2631,10 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, err = ext4_ext_correct_indexes(handle, inode, path); /* - * If there is still a entry in the leaf node, check to see if - * it references the partial cluster. This is the only place - * where it could; if it doesn't, we can free the cluster. + * Free the partial cluster only if the current extent does not + * reference it. Otherwise we might free used cluster. */ - if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) && + if (*partial_cluster > 0 && (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) != *partial_cluster)) { int flags = EXT4_FREE_BLOCKS_FORGET; @@ -2651,7 +2684,7 @@ int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, struct super_block *sb = inode->i_sb; int depth = ext_depth(inode); struct ext4_ext_path *path = NULL; - ext4_fsblk_t partial_cluster = 0; + long long partial_cluster = 0; handle_t *handle; int i = 0, err = 0; @@ -2837,7 +2870,7 @@ again: /* If we still have something in the partial cluster and we have removed * even the first extent, then we should free the blocks in the partial * cluster as well. */ - if (partial_cluster && path->p_hdr->eh_entries == 0) { + if (partial_cluster > 0 && path->p_hdr->eh_entries == 0) { int flags = EXT4_FREE_BLOCKS_FORGET; if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) |