On 2022/10/25 14:27, zhangqilong wrote:
On 2022/10/20 15:27, zhangqilong via Linux-f2fs-devel wrote:
On 2022/10/18 10:45, Zhang Qilong wrote:
In the following case:
process 1 process 2
->open A
->mmap
->read # the first time
->ioctl w/h F2FS_IOC_MOVE_RANGE
# (range A->B)
->read # the second time
How about checking B as well? Previous mapped data can still be
accessed after F2FS_IOC_MOVE_RANGE?
Hi
I have checked B as well. Previous mapped data can't be accessed after
F2FS_IOC_MOVE_RANGE.
I doubt that we didn't call flush_dcache_page() in below branch, so user may
see stall data after F2FS_IOC_MOVE_RANGE? Am I missing something?
Hi,
You are right, it needs flush_dcache_page, but it is unnecessary here, the
__clone_blkaddrs() is called by
FALLOC_FL_COLLAPSE_RANGE/ FALLOC_FL_INSERT_RANGE /F2FS_IOC_MOVE_RANGE.
->__exchange_data_block()
->__clone_blkaddrs()
f2fs_do_collapse() and f2fs_insert_range() have truncate_pagecache after
__exchange_data_block()
It seem we have analyzed before. So we only need to add a truncate operation
for F2FS_IOC_MOVE_RANGE.
I mean it needs to call truncate_pagecache_range(dst, ...) in
f2fs_move_file_range() as well, right?
Thanks,
__clone_blkaddrs()
{
...
} else {
struct page *psrc, *pdst;
psrc = f2fs_get_lock_data_page(src_inode,
src + i, true);
if (IS_ERR(psrc))
return PTR_ERR(psrc);
pdst = f2fs_get_new_data_page(dst_inode, NULL,
dst + i,
true);
if (IS_ERR(pdst)) {
f2fs_put_page(psrc, 1);
return PTR_ERR(pdst);
}
memcpy_page(pdst, 0, psrc, 0, PAGE_SIZE);
set_page_dirty(pdst);
f2fs_put_page(pdst, 1);
f2fs_put_page(psrc, 1);
ret = f2fs_truncate_hole(src_inode,
src + i, src + i + 1);
if (ret)
return ret;
i++;
}
...
}
Thanks,
In addition, this patch could be applied to mainline if possible?
Thanks
Thanks,
We will read old data at the second time. The root cause is that
user still can see the previous source data after being moved. We
fix it by adding truncating after __exchange_data_block.
Fixes: 4dd6f977fc77 ("f2fs: support an ioctl to move a range of data
blocks")
Signed-off-by: Zhang Qilong <zhangqilo...@huawei.com>
---
v2:
- moving truncating to the range of f2fs_lock_op()
v3:
- modify the title and commit message
---
fs/f2fs/file.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index
82cda1258227..e9dfa41baf9e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -2824,6 +2824,7 @@ static int f2fs_move_file_range(struct file
*file_in,
loff_t pos_in,
goto out_src;
}
+ filemap_invalidate_lock(src->i_mapping);
f2fs_lock_op(sbi);
ret = __exchange_data_block(src, dst, pos_in >> F2FS_BLKSIZE_BITS,
pos_out >> F2FS_BLKSIZE_BITS, @@ -2835,7
+2836,9 @@ static
int f2fs_move_file_range(struct file *file_in,
loff_t pos_in,
else if (dst_osize != dst->i_size)
f2fs_i_size_write(dst, dst_osize);
}
+ truncate_pagecache_range(src, pos_in, pos_in + len - 1);
f2fs_unlock_op(sbi);
+ filemap_invalidate_unlock(src->i_mapping);
if (src != dst)
f2fs_up_write(&F2FS_I(dst)->i_gc_rwsem[WRITE]);
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
