diff options
| -rw-r--r-- | fs/ext4/ext4.h | 3 | ||||
| -rw-r--r-- | fs/ext4/extents.c | 236 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 25 |
3 files changed, 253 insertions, 11 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index c48f9db..7bc7c72 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1816,6 +1816,7 @@ extern int ext4_change_inode_journal_flag(struct inode *, int); extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *); extern int ext4_can_truncate(struct inode *inode); extern void ext4_truncate(struct inode *); +extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length); extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks); extern void ext4_set_inode_flags(struct inode *); extern void ext4_get_inode_flags(struct ext4_inode_info *); @@ -2157,6 +2158,8 @@ extern int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, struct ext4_map_blocks *map, int flags); extern void ext4_ext_truncate(struct inode *); +extern int ext4_ext_punch_hole(struct file *file, loff_t offset, + loff_t length); extern void ext4_ext_init(struct super_block *); extern void ext4_ext_release(struct super_block *); extern long ext4_fallocate(struct file *file, int mode, loff_t offset, diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 1d456b2..88ff3a7 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2044,12 +2044,23 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, } /* + * ext4_ext_in_cache() + * Checks to see if the given block is in the cache. + * If it is, the cached extent is stored in the given + * cache extent pointer. If the cached extent is a hole, + * this routine should be used instead of + * ext4_ext_in_cache if the calling function needs to + * know the size of the hole. + * + * @inode: The files inode + * @block: The block to look for in the cache + * @ex: Pointer where the cached extent will be stored + * if it contains block + * * Return 0 if cache is invalid; 1 if the cache is valid */ -static int -ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, - struct ext4_extent *ex) -{ +static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block, + struct ext4_ext_cache *ex){ struct ext4_ext_cache *cex; struct ext4_sb_info *sbi; int ret = 0; @@ -2066,9 +2077,7 @@ ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, goto errout; if (in_range(block, cex->ec_block, cex->ec_len)) { - ex->ee_block = cpu_to_le32(cex->ec_block); - ext4_ext_store_pblock(ex, cex->ec_start); - ex->ee_len = cpu_to_le16(cex->ec_len); + memcpy(ex, cex, sizeof(struct ext4_ext_cache)); ext_debug("%u cached by %u:%u:%llu\n", block, cex->ec_block, cex->ec_len, cex->ec_start); @@ -2084,6 +2093,37 @@ errout: } /* + * ext4_ext_in_cache() + * Checks to see if the given block is in the cache. + * If it is, the cached extent is stored in the given + * extent pointer. + * + * @inode: The files inode + * @block: The block to look for in the cache + * @ex: Pointer where the cached extent will be stored + * if it contains block + * + * Return 0 if cache is invalid; 1 if the cache is valid + */ +static int +ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block, + struct ext4_extent *ex) +{ + struct ext4_ext_cache cex; + int ret = 0; + + if (ext4_ext_check_cache(inode, block, &cex)) { + ex->ee_block = cpu_to_le32(cex.ec_block); + ext4_ext_store_pblock(ex, cex.ec_start); + ex->ee_len = cpu_to_le16(cex.ec_len); + ret = 1; + } + + return ret; +} + + +/* * ext4_ext_rm_idx: * removes index from the index block. * It's used in truncate case only, thus all requests are for @@ -3724,10 +3764,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) struct ext4_map_blocks map; unsigned int credits, blkbits = inode->i_blkbits; - /* We only support the FALLOC_FL_KEEP_SIZE mode */ - if (mode & ~FALLOC_FL_KEEP_SIZE) - return -EOPNOTSUPP; - /* * currently supporting (pre)allocate mode for extent-based * files _only_ @@ -3735,6 +3771,13 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) return -EOPNOTSUPP; + /* Return error if mode is not supported */ + if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) + return -EOPNOTSUPP; + + if (mode & FALLOC_FL_PUNCH_HOLE) + return ext4_punch_hole(file, offset, len); + trace_ext4_fallocate_enter(inode, offset, len, mode); map.m_lblk = offset >> blkbits; /* @@ -4100,6 +4143,177 @@ static int ext4_xattr_fiemap(struct inode *inode, return (error < 0 ? error : 0); } +/* + * ext4_ext_punch_hole + * + * Punches a hole of "length" bytes in a file starting + * at byte "offset" + * + * @inode: The inode of the file to punch a hole in + * @offset: The starting byte offset of the hole + * @length: The length of the hole + * + * Returns the number of blocks removed or negative on err + */ +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; + struct address_space *mapping = inode->i_mapping; + struct ext4_map_blocks map; + handle_t *handle; + loff_t first_block_offset, last_block_offset, block_len; + loff_t first_page, last_page, first_page_offset, last_page_offset; + int ret, credits, blocks_released, err = 0; + + first_block = (offset + sb->s_blocksize - 1) >> + EXT4_BLOCK_SIZE_BITS(sb); + last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); + + first_block_offset = first_block << EXT4_BLOCK_SIZE_BITS(sb); + last_block_offset = last_block << EXT4_BLOCK_SIZE_BITS(sb); + + first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; + last_page = (offset + length) >> PAGE_CACHE_SHIFT; + + first_page_offset = first_page << PAGE_CACHE_SHIFT; + last_page_offset = last_page << PAGE_CACHE_SHIFT; + + /* + * Write out all dirty pages to avoid race conditions + * Then release them. + */ + if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { + err = filemap_write_and_wait_range(mapping, + first_page_offset == 0 ? 0 : first_page_offset-1, + last_page_offset); + + if (err) + return err; + } + + /* Now release the pages */ + if (last_page_offset > first_page_offset) { + truncate_inode_pages_range(mapping, first_page_offset, + last_page_offset-1); + } + + /* finish any pending end_io work */ + ext4_flush_completed_IO(inode); + + credits = ext4_writepage_trans_blocks(inode); + handle = ext4_journal_start(inode, credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + err = ext4_orphan_add(handle, inode); + if (err) + goto out; + + /* + * Now we need to zero out the un block aligned data. + * If the file is smaller than a block, just + * zero out the middle + */ + if (first_block > last_block) + ext4_block_zero_page_range(handle, mapping, offset, length); + else { + /* zero out the head of the hole before the first block */ + block_len = first_block_offset - offset; + if (block_len > 0) + ext4_block_zero_page_range(handle, mapping, + offset, block_len); + + /* zero out the tail of the hole after the last block */ + block_len = offset + length - last_block_offset; + if (block_len > 0) { + ext4_block_zero_page_range(handle, mapping, + last_block_offset, block_len); + } + } + + /* If there are no blocks to remove, return now */ + if (first_block >= last_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) { + + /* 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); + } + + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + + up_write(&EXT4_I(inode)->i_data_sem); + +out: + ext4_orphan_del(handle, inode); + inode->i_mtime = inode->i_ctime = ext4_current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); + return err; +} int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, __u64 start, __u64 len) { diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index fbe11e6..65576c0 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4419,6 +4419,31 @@ int ext4_can_truncate(struct inode *inode) } /* + * ext4_punch_hole: punches a hole in a file by releaseing the blocks + * associated with the given offset and length + * + * @inode: File inode + * @offset: The offset where the hole will begin + * @len: The length of the hole + * + * Returns: 0 on sucess or negative on failure + */ + +int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) +{ + struct inode *inode = file->f_path.dentry->d_inode; + if (!S_ISREG(inode->i_mode)) + return -ENOTSUPP; + + if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + /* TODO: Add support for non extent hole punching */ + return -ENOTSUPP; + } + + return ext4_ext_punch_hole(file, offset, length); +} + +/* * ext4_truncate() * * We block out ext4_get_block() block instantiations across the entire |