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f2fs: allocate blocks for pinned file 

This patch allows fallocate to allocate physical blocks for pinned file.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2019-06-26 18:23:05 -07:00
parent 56659ce838
commit cad3836f9e
2 changed files with 31 additions and 1 deletions
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25
Documentation/filesystems/f2fs.txt
View File

@ -804,3 +804,28 @@ WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
WRITE_LIFE_NONE " WRITE_LIFE_NONE
WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM
WRITE_LIFE_LONG " WRITE_LIFE_LONG
Fallocate(2) Policy
-------------------
The default policy follows the below posix rule.
Allocating disk space
The default operation (i.e., mode is zero) of fallocate() allocates
the disk space within the range specified by offset and len. The
file size (as reported by stat(2)) will be changed if offset+len is
greater than the file size. Any subregion within the range specified
by offset and len that did not contain data before the call will be
initialized to zero. This default behavior closely resembles the
behavior of the posix_fallocate(3) library function, and is intended
as a method of optimally implementing that function.
However, once F2FS receives ioctl(fd, F2FS_IOC_SET_PIN_FILE) in prior to
fallocate(fd, DEFAULT_MODE), it allocates on-disk blocks addressess having
zero or random data, which is useful to the below scenario where:
1. create(fd)
2. ioctl(fd, F2FS_IOC_SET_PIN_FILE)
3. fallocate(fd, 0, 0, size)
4. address = fibmap(fd, offset)
5. open(blkdev)
6. write(blkdev, address)

7
fs/f2fs/file.c
View File

@ -1528,7 +1528,12 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
if (off_end)
map.m_len++;
err = f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
if (f2fs_is_pinned_file(inode))
map.m_seg_type = CURSEG_COLD_DATA;
err = f2fs_map_blocks(inode, &map, 1, (f2fs_is_pinned_file(inode) ?
F2FS_GET_BLOCK_PRE_DIO :
F2FS_GET_BLOCK_PRE_AIO));
if (err) {
pgoff_t last_off;