[PATCH 5.12 138/363] f2fs: fix to update last i_size if fallocate partially succeeds

From: Greg Kroah-Hartman
Date: Mon May 17 2021 - 10:22:15 EST


From: Chao Yu <yuchao0@xxxxxxxxxx>

[ Upstream commit 88f2cfc5fa90326edb569b4a81bb38ed4dcd3108 ]

In the case of expanding pinned file, map.m_lblk and map.m_len
will update in each round of section allocation, so in error
path, last i_size will be calculated with wrong m_lblk and m_len,
fix it.

Fixes: f5a53edcf01e ("f2fs: support aligned pinned file")
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/f2fs/file.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index bd5a77091d23..dc79694e512c 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1619,9 +1619,10 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
.m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE,
.m_may_create = true };
- pgoff_t pg_end;
+ pgoff_t pg_start, pg_end;
loff_t new_size = i_size_read(inode);
loff_t off_end;
+ block_t expanded = 0;
int err;

err = inode_newsize_ok(inode, (len + offset));
@@ -1634,11 +1635,12 @@ static int expand_inode_data(struct inode *inode, loff_t offset,

f2fs_balance_fs(sbi, true);

+ pg_start = ((unsigned long long)offset) >> PAGE_SHIFT;
pg_end = ((unsigned long long)offset + len) >> PAGE_SHIFT;
off_end = (offset + len) & (PAGE_SIZE - 1);

- map.m_lblk = ((unsigned long long)offset) >> PAGE_SHIFT;
- map.m_len = pg_end - map.m_lblk;
+ map.m_lblk = pg_start;
+ map.m_len = pg_end - pg_start;
if (off_end)
map.m_len++;

@@ -1648,7 +1650,6 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
if (f2fs_is_pinned_file(inode)) {
block_t sec_blks = BLKS_PER_SEC(sbi);
block_t sec_len = roundup(map.m_len, sec_blks);
- block_t done = 0;

map.m_len = sec_blks;
next_alloc:
@@ -1656,10 +1657,8 @@ next_alloc:
GET_SEC_FROM_SEG(sbi, overprovision_segments(sbi)))) {
down_write(&sbi->gc_lock);
err = f2fs_gc(sbi, true, false, false, NULL_SEGNO);
- if (err && err != -ENODATA && err != -EAGAIN) {
- map.m_len = done;
+ if (err && err != -ENODATA && err != -EAGAIN)
goto out_err;
- }
}

down_write(&sbi->pin_sem);
@@ -1673,24 +1672,25 @@ next_alloc:

up_write(&sbi->pin_sem);

- done += map.m_len;
+ expanded += map.m_len;
sec_len -= map.m_len;
map.m_lblk += map.m_len;
if (!err && sec_len)
goto next_alloc;

- map.m_len = done;
+ map.m_len = expanded;
} else {
err = f2fs_map_blocks(inode, &map, 1, F2FS_GET_BLOCK_PRE_AIO);
+ expanded = map.m_len;
}
out_err:
if (err) {
pgoff_t last_off;

- if (!map.m_len)
+ if (!expanded)
return err;

- last_off = map.m_lblk + map.m_len - 1;
+ last_off = pg_start + expanded - 1;

/* update new size to the failed position */
new_size = (last_off == pg_end) ? offset + len :
--
2.30.2