This is a note to let you know that I've just added the patch titled
f2fs: enhance to update i_mode and acl atomically in f2fs_setattr()
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
f2fs-enhance-to-update-i_mode-and-acl-atomically-in-.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2edc3660c5239bc3419441521d5bf2f2023893e9
Author: Chao Yu <chao@xxxxxxxxxx>
Date: Fri Dec 25 16:52:27 2020 +0800
f2fs: enhance to update i_mode and acl atomically in f2fs_setattr()
[ Upstream commit 17232e830afb800acdcc22ae8980bf9d330393ef ]
Previously, in f2fs_setattr(), we don't update S_ISUID|S_ISGID|S_ISVTX
bits with S_IRWXUGO bits and acl entries atomically, so in error path,
chmod() may partially success, this patch enhances to make chmod() flow
being atomical.
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Stable-dep-of: aaf8c0b9ae04 ("f2fs: reduce expensive checkpoint trigger frequency")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/f2fs/acl.c b/fs/f2fs/acl.c
index b9fe937a3c701..cc53d4c80b0a9 100644
--- a/fs/f2fs/acl.c
+++ b/fs/f2fs/acl.c
@@ -200,6 +200,27 @@ struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
return __f2fs_get_acl(inode, type, NULL);
}
+static int f2fs_acl_update_mode(struct inode *inode, umode_t *mode_p,
+ struct posix_acl **acl)
+{
+ umode_t mode = inode->i_mode;
+ int error;
+
+ if (is_inode_flag_set(inode, FI_ACL_MODE))
+ mode = F2FS_I(inode)->i_acl_mode;
+
+ error = posix_acl_equiv_mode(*acl, &mode);
+ if (error < 0)
+ return error;
+ if (error == 0)
+ *acl = NULL;
+ if (!in_group_p(inode->i_gid) &&
+ !capable_wrt_inode_uidgid(inode, CAP_FSETID))
+ mode &= ~S_ISGID;
+ *mode_p = mode;
+ return 0;
+}
+
static int __f2fs_set_acl(struct inode *inode, int type,
struct posix_acl *acl, struct page *ipage)
{
@@ -213,7 +234,7 @@ static int __f2fs_set_acl(struct inode *inode, int type,
case ACL_TYPE_ACCESS:
name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
if (acl && !ipage) {
- error = posix_acl_update_mode(inode, &mode, &acl);
+ error = f2fs_acl_update_mode(inode, &mode, &acl);
if (error)
return error;
set_acl_inode(inode, mode);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 043ce96ac1270..e44cb6bf68b9e 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -839,8 +839,10 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
if (attr->ia_valid & ATTR_MODE) {
err = posix_acl_chmod(inode, f2fs_get_inode_mode(inode));
- if (err || is_inode_flag_set(inode, FI_ACL_MODE)) {
- inode->i_mode = F2FS_I(inode)->i_acl_mode;
+
+ if (is_inode_flag_set(inode, FI_ACL_MODE)) {
+ if (!err)
+ inode->i_mode = F2FS_I(inode)->i_acl_mode;
clear_inode_flag(inode, FI_ACL_MODE);
}
}
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index db3e76b35607b..496a9e70cb091 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -651,7 +651,7 @@ static int __f2fs_setxattr(struct inode *inode, int index,
}
if (value && f2fs_xattr_value_same(here, value, size))
- goto exit;
+ goto same;
} else if ((flags & XATTR_REPLACE)) {
error = -ENODATA;
goto exit;
@@ -729,17 +729,20 @@ static int __f2fs_setxattr(struct inode *inode, int index,
if (error)
goto exit;
- if (is_inode_flag_set(inode, FI_ACL_MODE)) {
- inode->i_mode = F2FS_I(inode)->i_acl_mode;
- inode->i_ctime = current_time(inode);
- clear_inode_flag(inode, FI_ACL_MODE);
- }
if (index == F2FS_XATTR_INDEX_ENCRYPTION &&
!strcmp(name, F2FS_XATTR_NAME_ENCRYPTION_CONTEXT))
f2fs_set_encrypted_inode(inode);
f2fs_mark_inode_dirty_sync(inode, true);
if (!error && S_ISDIR(inode->i_mode))
set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_CP);
+
+same:
+ if (is_inode_flag_set(inode, FI_ACL_MODE)) {
+ inode->i_mode = F2FS_I(inode)->i_acl_mode;
+ inode->i_ctime = current_time(inode);
+ clear_inode_flag(inode, FI_ACL_MODE);
+ }
+
exit:
kzfree(base_addr);
return error;
