diff options
| -rw-r--r-- | fs/ext4/extents.c | 170 |
1 files changed, 88 insertions, 82 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4394a757..4726a3a 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -44,6 +44,14 @@ #include <trace/events/ext4.h> +/* + * used by extent splitting. + */ +#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ + due to ENOSPC */ +#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */ +#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */ + static int ext4_split_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, @@ -51,6 +59,13 @@ static int ext4_split_extent(handle_t *handle, int split_flag, int flags); +static int ext4_split_extent_at(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t split, + int split_flag, + int flags); + static int ext4_ext_truncate_extend_restart(handle_t *handle, struct inode *inode, int needed) @@ -2310,7 +2325,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, struct ext4_extent *ex; /* the header must be checked already in ext4_ext_remove_space() */ - ext_debug("truncate since %u in leaf\n", start); + ext_debug("truncate since %u in leaf to %u\n", start, end); if (!path[depth].p_hdr) path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); eh = path[depth].p_hdr; @@ -2345,7 +2360,7 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, ext_debug(" border %u:%u\n", a, b); /* If this extent is beyond the end of the hole, skip it */ - if (end <= ex_ee_block) { + if (end < ex_ee_block) { ex--; ex_ee_block = le32_to_cpu(ex->ee_block); ex_ee_len = ext4_ext_get_actual_len(ex); @@ -2484,7 +2499,8 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path) return 1; } -static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) +static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, + ext4_lblk_t end) { struct super_block *sb = inode->i_sb; int depth = ext_depth(inode); @@ -2493,7 +2509,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) handle_t *handle; int i, err; - ext_debug("truncate since %u\n", start); + ext_debug("truncate since %u to %u\n", start, end); /* probably first extent we're gonna free will be last in block */ handle = ext4_journal_start(inode, depth + 1); @@ -2506,6 +2522,61 @@ again: trace_ext4_ext_remove_space(inode, start, depth); /* + * Check if we are removing extents inside the extent tree. If that + * is the case, we are going to punch a hole inside the extent tree + * so we have to check whether we need to split the extent covering + * the last block to remove so we can easily remove the part of it + * in ext4_ext_rm_leaf(). + */ + if (end < EXT_MAX_BLOCKS - 1) { + struct ext4_extent *ex; + ext4_lblk_t ee_block; + + /* find extent for this block */ + path = ext4_ext_find_extent(inode, end, NULL); + if (IS_ERR(path)) { + ext4_journal_stop(handle); + return PTR_ERR(path); + } + depth = ext_depth(inode); + ex = path[depth].p_ext; + if (!ex) + goto cont; + + ee_block = le32_to_cpu(ex->ee_block); + + /* + * See if the last block is inside the extent, if so split + * the extent at 'end' block so we can easily remove the + * tail of the first part of the split extent in + * ext4_ext_rm_leaf(). + */ + if (end >= ee_block && + end < ee_block + ext4_ext_get_actual_len(ex) - 1) { + int split_flag = 0; + + if (ext4_ext_is_uninitialized(ex)) + split_flag = EXT4_EXT_MARK_UNINIT1 | + EXT4_EXT_MARK_UNINIT2; + + /* + * Split the extent in two so that 'end' is the last + * block in the first new extent + */ + err = ext4_split_extent_at(handle, inode, path, + end + 1, split_flag, + EXT4_GET_BLOCKS_PRE_IO | + EXT4_GET_BLOCKS_PUNCH_OUT_EXT); + + if (err < 0) + goto out; + } + ext4_ext_drop_refs(path); + kfree(path); + } +cont: + + /* * We start scanning from right side, freeing all the blocks * after i_size and walking into the tree depth-wise. */ @@ -2517,6 +2588,7 @@ again: } path[0].p_depth = depth; path[0].p_hdr = ext_inode_hdr(inode); + if (ext4_ext_check(inode, path[0].p_hdr, depth)) { err = -EIO; goto out; @@ -2528,7 +2600,7 @@ again: /* this is leaf block */ err = ext4_ext_rm_leaf(handle, inode, path, &partial_cluster, start, - EXT_MAX_BLOCKS - 1); + end); /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; @@ -2711,14 +2783,6 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) } /* - * used by extent splitting. - */ -#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \ - due to ENOSPC */ -#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */ -#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */ - -/* * ext4_split_extent_at() splits an extent at given block. * * @handle: the journal handle @@ -4230,7 +4294,7 @@ void ext4_ext_truncate(struct inode *inode) last_block = (inode->i_size + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); - err = ext4_ext_remove_space(inode, last_block); + err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1); /* In a multi-transaction truncate, we only make the final * transaction synchronous. @@ -4707,14 +4771,12 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) { struct inode *inode = file->f_path.dentry->d_inode; struct super_block *sb = inode->i_sb; - struct ext4_ext_cache cache_ex; - ext4_lblk_t first_block, last_block, num_blocks, iblock, max_blocks; + ext4_lblk_t first_block, stop_block; struct address_space *mapping = inode->i_mapping; - struct ext4_map_blocks map; handle_t *handle; loff_t first_page, last_page, page_len; loff_t first_page_offset, last_page_offset; - int ret, credits, blocks_released, err = 0; + int credits, err = 0; /* No need to punch hole beyond i_size */ if (offset >= inode->i_size) @@ -4730,10 +4792,6 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) offset; } - first_block = (offset + sb->s_blocksize - 1) >> - EXT4_BLOCK_SIZE_BITS(sb); - last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); - first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; last_page = (offset + length) >> PAGE_CACHE_SHIFT; @@ -4812,7 +4870,6 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) } } - /* * If i_size is contained in the last page, we need to * unmap and zero the partial page after i_size @@ -4832,73 +4889,22 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) } } + first_block = (offset + sb->s_blocksize - 1) >> + EXT4_BLOCK_SIZE_BITS(sb); + stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); + /* If there are no blocks to remove, return now */ - if (first_block >= last_block) + if (first_block >= stop_block) goto out; down_write(&EXT4_I(inode)->i_data_sem); ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); - /* - * Loop over all the blocks and identify blocks - * that need to be punched out - */ - iblock = first_block; - blocks_released = 0; - while (iblock < last_block) { - max_blocks = last_block - iblock; - num_blocks = 1; - memset(&map, 0, sizeof(map)); - map.m_lblk = iblock; - map.m_len = max_blocks; - ret = ext4_ext_map_blocks(handle, inode, &map, - EXT4_GET_BLOCKS_PUNCH_OUT_EXT); - - if (ret > 0) { - blocks_released += ret; - num_blocks = ret; - } else if (ret == 0) { - /* - * If map blocks could not find the block, - * then it is in a hole. If the hole was - * not already cached, then map blocks should - * put it in the cache. So we can get the hole - * out of the cache - */ - memset(&cache_ex, 0, sizeof(cache_ex)); - if ((ext4_ext_check_cache(inode, iblock, &cache_ex)) && - !cache_ex.ec_start) { + err = ext4_ext_remove_space(inode, first_block, stop_block - 1); - /* The hole is cached */ - num_blocks = cache_ex.ec_block + - cache_ex.ec_len - iblock; - - } else { - /* The block could not be identified */ - err = -EIO; - break; - } - } else { - /* Map blocks error */ - err = ret; - break; - } - - if (num_blocks == 0) { - /* This condition should never happen */ - ext_debug("Block lookup failed"); - err = -EIO; - break; - } - - iblock += num_blocks; - } - - if (blocks_released > 0) { - ext4_ext_invalidate_cache(inode); - ext4_discard_preallocations(inode); - } + ext4_ext_invalidate_cache(inode); + ext4_discard_preallocations(inode); if (IS_SYNC(inode)) ext4_handle_sync(handle); |
