From: Daeho Jeong <daeho43@gmail.com>
To: kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net,
kernel-team@android.com, jaegeuk@kernel.org, yuchao0@huawei.com
Cc: Daeho Jeong <daehojeong@google.com>
Subject: [f2fs-dev] [PATCH] f2fs: remove race condition in releasing cblocks
Date: Fri, 8 May 2020 18:29:21 +0900 [thread overview]
Message-ID: <20200508092921.208447-1-daeho43@gmail.com> (raw)
From: Daeho Jeong <daehojeong@google.com>
Now, if writing pages and releasing compress blocks occur
simultaneously, and releasing cblocks is executed more than one time
to a file, then total block count of filesystem and block count of the
file could be incorrect and damaged.
We have to execute releasing compress blocks only one time for a file
without being interfered by writepages path.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
---
fs/f2fs/file.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 4aab4b42d8ba..f7de2a1da528 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -3488,6 +3488,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
pgoff_t page_idx = 0, last_idx;
unsigned int released_blocks = 0;
int ret;
+ int writecount;
if (!f2fs_sb_has_compression(F2FS_I_SB(inode)))
return -EOPNOTSUPP;
@@ -3502,20 +3503,33 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
if (ret)
return ret;
- if (!F2FS_I(inode)->i_compr_blocks)
- goto out;
-
f2fs_balance_fs(F2FS_I_SB(inode), true);
inode_lock(inode);
- if (!IS_IMMUTABLE(inode)) {
- F2FS_I(inode)->i_flags |= F2FS_IMMUTABLE_FL;
- f2fs_set_inode_flags(inode);
- inode->i_ctime = current_time(inode);
- f2fs_mark_inode_dirty_sync(inode, true);
+ writecount = atomic_read(&inode->i_writecount);
+ if ((filp->f_mode & FMODE_WRITE && writecount != 1) || writecount) {
+ ret = -EBUSY;
+ goto out;
}
+ if (IS_IMMUTABLE(inode)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
+ if (ret)
+ goto out;
+
+ if (!F2FS_I(inode)->i_compr_blocks)
+ goto out;
+
+ F2FS_I(inode)->i_flags |= F2FS_IMMUTABLE_FL;
+ f2fs_set_inode_flags(inode);
+ inode->i_ctime = current_time(inode);
+ f2fs_mark_inode_dirty_sync(inode, true);
+
down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
down_write(&F2FS_I(inode)->i_mmap_sem);
@@ -3554,9 +3568,9 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg)
up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
up_write(&F2FS_I(inode)->i_mmap_sem);
-
- inode_unlock(inode);
out:
+ inode_unlock(inode);
+
mnt_drop_write_file(filp);
if (ret >= 0) {
--
2.26.2.645.ge9eca65c58-goog
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next reply other threads:[~2020-05-08 9:29 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-08 9:29 Daeho Jeong [this message]
2020-05-08 10:09 ` [f2fs-dev] [PATCH] f2fs: remove race condition in releasing cblocks Chao Yu
2020-05-08 13:47 ` Jaegeuk Kim
-- strict thread matches above, loose matches on Subject: below --
2020-05-08 11:56 Daeho Jeong
2020-05-08 13:48 ` Jaegeuk Kim
2020-05-08 13:58 ` Jaegeuk Kim
2020-05-08 4:25 Daeho Jeong
2020-05-08 6:50 ` Chao Yu
2020-05-08 6:58 ` Daeho Jeong
2020-05-08 7:09 ` Chao Yu
2020-05-08 7:10 ` Daeho Jeong
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