From: Lukas Czerner Date: Tue, 18 Mar 2014 22:03:51 +0000 (-0400) Subject: ext4: refactor ext4_fallocate code X-Git-Tag: firefly_0821_release~176^2~4145^2~11 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=0e8b6879f3c234036181526683be2b0231892ae4;p=firefly-linux-kernel-4.4.55.git ext4: refactor ext4_fallocate code Move block allocation out of the ext4_fallocate into separate function called ext4_alloc_file_blocks(). This will allow us to use the same allocation code for other allocation operations such as zero range which is commit in the next patch. Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index e4be6b79121d..2db2d77769a2 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4546,6 +4546,64 @@ retry: ext4_std_error(inode->i_sb, err); } +static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, + ext4_lblk_t len, int flags, int mode) +{ + struct inode *inode = file_inode(file); + handle_t *handle; + int ret = 0; + int ret2 = 0; + int retries = 0; + struct ext4_map_blocks map; + unsigned int credits; + + map.m_lblk = offset; + /* + * Don't normalize the request if it can fit in one extent so + * that it doesn't get unnecessarily split into multiple + * extents. + */ + if (len <= EXT_UNINIT_MAX_LEN) + flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; + + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, len); + +retry: + while (ret >= 0 && ret < len) { + map.m_lblk = map.m_lblk + ret; + map.m_len = len = len - ret; + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, + credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + ret = ext4_map_blocks(handle, inode, &map, flags); + if (ret <= 0) { + ext4_debug("inode #%lu: block %u: len %u: " + "ext4_ext_map_blocks returned %d", + inode->i_ino, map.m_lblk, + map.m_len, ret); + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + break; + } + ret2 = ext4_journal_stop(handle); + if (ret2) + break; + } + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) { + ret = 0; + goto retry; + } + + return ret > 0 ? ret2 : ret; +} + /* * preallocate space for a file. This implements ext4's fallocate file * operation, which gets called from sys_fallocate system call. @@ -4560,12 +4618,10 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) loff_t new_size = 0; unsigned int max_blocks; int ret = 0; - int ret2 = 0; - int retries = 0; int flags; - struct ext4_map_blocks map; + ext4_lblk_t lblk; struct timespec tv; - unsigned int credits, blkbits = inode->i_blkbits; + unsigned int blkbits = inode->i_blkbits; /* Return error if mode is not supported */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | @@ -4590,17 +4646,18 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) return -EOPNOTSUPP; trace_ext4_fallocate_enter(inode, offset, len, mode); - map.m_lblk = offset >> blkbits; + lblk = offset >> blkbits; /* * We can't just convert len to max_blocks because * If blocksize = 4096 offset = 3072 and len = 2048 */ max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) - - map.m_lblk; - /* - * credits to insert 1 extent into extent tree - */ - credits = ext4_chunk_trans_blocks(inode, max_blocks); + - lblk; + + flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; + if (mode & FALLOC_FL_KEEP_SIZE) + flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + mutex_lock(&inode->i_mutex); if (!(mode & FALLOC_FL_KEEP_SIZE) && @@ -4611,46 +4668,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) goto out; } - flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; - if (mode & FALLOC_FL_KEEP_SIZE) - flags |= EXT4_GET_BLOCKS_KEEP_SIZE; - /* - * Don't normalize the request if it can fit in one extent so - * that it doesn't get unnecessarily split into multiple - * extents. - */ - if (len <= EXT_UNINIT_MAX_LEN << blkbits) - flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; - -retry: - while (ret >= 0 && ret < max_blocks) { - map.m_lblk = map.m_lblk + ret; - map.m_len = max_blocks = max_blocks - ret; - handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, - credits); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - break; - } - ret = ext4_map_blocks(handle, inode, &map, flags); - if (ret <= 0) { - ext4_debug("inode #%lu: block %u: len %u: " - "ext4_ext_map_blocks returned %d", - inode->i_ino, map.m_lblk, - map.m_len, ret); - ext4_mark_inode_dirty(handle, inode); - ret2 = ext4_journal_stop(handle); - break; - } - ret2 = ext4_journal_stop(handle); - if (ret2) - break; - } - if (ret == -ENOSPC && - ext4_should_retry_alloc(inode->i_sb, &retries)) { - ret = 0; - goto retry; - } + ret = ext4_alloc_file_blocks(file, lblk, max_blocks, flags, mode); + if (ret) + goto out; handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); if (IS_ERR(handle)) @@ -4658,14 +4678,14 @@ retry: tv = inode->i_ctime = ext4_current_time(inode); - if (ret > 0 && new_size) { + if (!ret && new_size) { if (new_size > i_size_read(inode)) { i_size_write(inode, new_size); inode->i_mtime = tv; } if (new_size > EXT4_I(inode)->i_disksize) ext4_update_i_disksize(inode, new_size); - } else if (ret > 0 && !new_size) { + } else if (!ret && !new_size) { /* * Mark that we allocate beyond EOF so the subsequent truncate * can proceed even if the new size is the same as i_size. @@ -4680,9 +4700,8 @@ retry: ext4_journal_stop(handle); out: mutex_unlock(&inode->i_mutex); - trace_ext4_fallocate_exit(inode, offset, max_blocks, - ret > 0 ? ret2 : ret); - return ret > 0 ? ret2 : ret; + trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); + return ret; } /*