Re: [PATCH 2/6] ext4: refactor ext4_fallocate code

jon ernst
2014-02-18T08:25:29Z

seems "int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,"
should be "static int ext4_alloc_file_blocks(struct file *file,
ext4_lblk_t offset,"

Jon

On Mon, Feb 17, 2014 at 3:08 PM, Lukas Czerner <lczerner@redhat.com> wrote:
> 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 <lczerner@redhat.com>
> ---
> fs/ext4/extents.c | 127 +++++++++++++++++++++++++++++++-----------------------
> 1 file changed, 73 insertions(+), 54 deletions(-)
>
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 6a52851..2d68a46 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4513,6 +4513,64 @@ retry:
> ext4_std_error(inode->i_sb, err);
> }
>
> +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.
> @@ -4527,11 +4585,9 @@ 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;
> - unsigned int credits, blkbits = inode->i_blkbits;
> + ext4_lblk_t lblk;
> + unsigned int blkbits = inode->i_blkbits;
>
> /* Return error if mode is not supported */
> if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
> @@ -4552,17 +4608,18 @@ 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) &&
> @@ -4573,46 +4630,9 @@ 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))
> @@ -4620,7 +4640,7 @@ retry:
>
> inode->i_mtime = 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);
> if (new_size > EXT4_I(inode)->i_disksize)
> @@ -4633,9 +4653,8 @@ 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;
> }
>
> /*
> --
> 1.8.3.1
>
> --
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