[PATCH 6/6] f2fs: set I_LINKABLE early to avoid wrong access by vfs

From: Jaegeuk Kim
Date: Mon Dec 09 2019 - 17:24:09 EST


This patch moves setting I_LINKABLE early in rename2(whiteout) to avoid the
below warning.

[ 3189.163385] WARNING: CPU: 3 PID: 59523 at fs/inode.c:358 inc_nlink+0x32/0x40
[ 3189.246979] Call Trace:
[ 3189.248707] f2fs_init_inode_metadata+0x2d6/0x440 [f2fs]
[ 3189.251399] f2fs_add_inline_entry+0x162/0x8c0 [f2fs]
[ 3189.254010] f2fs_add_dentry+0x69/0xe0 [f2fs]
[ 3189.256353] f2fs_do_add_link+0xc5/0x100 [f2fs]
[ 3189.258774] f2fs_rename2+0xabf/0x1010 [f2fs]
[ 3189.261079] vfs_rename+0x3f8/0xaa0
[ 3189.263056] ? tomoyo_path_rename+0x44/0x60
[ 3189.265283] ? do_renameat2+0x49b/0x550
[ 3189.267324] do_renameat2+0x49b/0x550
[ 3189.269316] __x64_sys_renameat2+0x20/0x30
[ 3189.271441] do_syscall_64+0x5a/0x230
[ 3189.273410] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 3189.275848] RIP: 0033:0x7f270b4d9a49

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/namei.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index a1c507b0b4ac..5d9584281935 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -797,6 +797,7 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,

if (whiteout) {
f2fs_i_links_write(inode, false);
+ inode->i_state |= I_LINKABLE;
*whiteout = inode;
} else {
d_tmpfile(dentry, inode);
@@ -867,6 +868,12 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
F2FS_I(old_dentry->d_inode)->i_projid)))
return -EXDEV;

+ if (flags & RENAME_WHITEOUT) {
+ err = f2fs_create_whiteout(old_dir, &whiteout);
+ if (err)
+ return err;
+ }
+
err = dquot_initialize(old_dir);
if (err)
goto out;
@@ -898,17 +905,11 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
}
}

- if (flags & RENAME_WHITEOUT) {
- err = f2fs_create_whiteout(old_dir, &whiteout);
- if (err)
- goto out_dir;
- }
-
if (new_inode) {

err = -ENOTEMPTY;
if (old_dir_entry && !f2fs_empty_dir(new_inode))
- goto out_whiteout;
+ goto out_dir;

err = -ENOENT;
new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name,
@@ -916,7 +917,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (!new_entry) {
if (IS_ERR(new_page))
err = PTR_ERR(new_page);
- goto out_whiteout;
+ goto out_dir;
}

f2fs_balance_fs(sbi, true);
@@ -948,7 +949,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
err = f2fs_add_link(new_dentry, old_inode);
if (err) {
f2fs_unlock_op(sbi);
- goto out_whiteout;
+ goto out_dir;
}

if (old_dir_entry)
@@ -972,7 +973,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
if (IS_ERR(old_page))
err = PTR_ERR(old_page);
f2fs_unlock_op(sbi);
- goto out_whiteout;
+ goto out_dir;
}
}
}
@@ -991,7 +992,6 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
f2fs_delete_entry(old_entry, old_page, old_dir, NULL);

if (whiteout) {
- whiteout->i_state |= I_LINKABLE;
set_inode_flag(whiteout, FI_INC_LINK);
err = f2fs_add_link(old_dentry, whiteout);
if (err)
@@ -1027,15 +1027,14 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
f2fs_unlock_op(sbi);
if (new_page)
f2fs_put_page(new_page, 0);
-out_whiteout:
- if (whiteout)
- iput(whiteout);
out_dir:
if (old_dir_entry)
f2fs_put_page(old_dir_page, 0);
out_old:
f2fs_put_page(old_page, 0);
out:
+ if (whiteout)
+ iput(whiteout);
return err;
}

--
2.19.0.605.g01d371f741-goog