The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6b4b8e6b4ad8553660421d6360678b3811d5deb9 Mon Sep 17 00:00:00 2001
From: yangerkun yangerkun@huawei.com Date: Tue, 5 Jan 2021 14:28:57 +0800 Subject: [PATCH] ext4: fix bug for rename with RENAME_WHITEOUT
We got a "deleted inode referenced" warning cross our fsstress test. The bug can be reproduced easily with following steps:
cd /dev/shm mkdir test/ fallocate -l 128M img mkfs.ext4 -b 1024 img mount img test/ dd if=/dev/zero of=test/foo bs=1M count=128 mkdir test/dir/ && cd test/dir/ for ((i=0;i<1000;i++)); do touch file$i; done # consume all block cd ~ && renameat2(AT_FDCWD, /dev/shm/test/dir/file1, AT_FDCWD, /dev/shm/test/dir/dst_file, RENAME_WHITEOUT) # ext4_add_entry in ext4_rename will return ENOSPC!! cd /dev/shm/ && umount test/ && mount img test/ && ls -li test/dir/file1 We will get the output: "ls: cannot access 'test/dir/file1': Structure needs cleaning" and the dmesg show: "EXT4-fs error (device loop0): ext4_lookup:1626: inode #2049: comm ls: deleted inode referenced: 139"
ext4_rename will create a special inode for whiteout and use this 'ino' to replace the source file's dir entry 'ino'. Once error happens latter(the error above was the ENOSPC return from ext4_add_entry in ext4_rename since all space has been consumed), the cleanup do drop the nlink for whiteout, but forget to restore 'ino' with source file. This will trigger the bug describle as above.
Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: Jan Kara jack@suse.cz Cc: stable@vger.kernel.org Fixes: cd808deced43 ("ext4: support RENAME_WHITEOUT") Link: https://lore.kernel.org/r/20210105062857.3566-1-yangerkun@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index a3b28ef2455a..fa625a247e9a 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3601,9 +3601,6 @@ static int ext4_setent(handle_t *handle, struct ext4_renament *ent, return retval2; } } - brelse(ent->bh); - ent->bh = NULL; - return retval; }
@@ -3802,6 +3799,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, } }
+ old_file_type = old.de->file_type; if (IS_DIRSYNC(old.dir) || IS_DIRSYNC(new.dir)) ext4_handle_sync(handle);
@@ -3829,7 +3827,6 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, force_reread = (new.dir->i_ino == old.dir->i_ino && ext4_test_inode_flag(new.dir, EXT4_INODE_INLINE_DATA));
- old_file_type = old.de->file_type; if (whiteout) { /* * Do this before adding a new entry, so the old entry is sure @@ -3927,15 +3924,19 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry, retval = 0;
end_rename: - brelse(old.dir_bh); - brelse(old.bh); - brelse(new.bh); if (whiteout) { - if (retval) + if (retval) { + ext4_setent(handle, &old, + old.inode->i_ino, old_file_type); drop_nlink(whiteout); + } unlock_new_inode(whiteout); iput(whiteout); + } + brelse(old.dir_bh); + brelse(old.bh); + brelse(new.bh); if (handle) ext4_journal_stop(handle); return retval;