Thread A                                Background GC
- f2fs_zero_range
 - truncate_pagecache_range
                                        - gc_data_segment
                                         - get_read_data_page
                                          - move_data_page
                                           - set_page_dirty
                                           - set_cold_data
 - f2fs_do_zero_range
  - dn->data_blkaddr = NEW_ADDR;
  - f2fs_set_data_blkaddr

Actually, we don't need to set dirty & checked flag on the page, since
all valid data in the page should be zeroed by zero_range().

Use i_gc_rwsem[WRITE] to avoid such race condition.

Signed-off-by: Chao Yu <yuch...@huawei.com>
---
 fs/f2fs/file.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 267ec3794e1e..7bd2412a8c37 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1309,6 +1309,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t 
offset, loff_t len,
        if (ret)
                return ret;
 
+       down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
        down_write(&F2FS_I(inode)->i_mmap_sem);
        ret = filemap_write_and_wait_range(mapping, offset, offset + len - 1);
        if (ret)
@@ -1389,6 +1390,7 @@ static int f2fs_zero_range(struct inode *inode, loff_t 
offset, loff_t len,
        }
 out_sem:
        up_write(&F2FS_I(inode)->i_mmap_sem);
+       up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 
        return ret;
 }
-- 
2.18.0.rc1


------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Linux-f2fs-devel mailing list
Linux-f2fs-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel

Reply via email to