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-rw-r--r--fs/overlayfs/inode.c108
1 files changed, 44 insertions, 64 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index 1b885c156028..c75625c1efa3 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -10,6 +10,7 @@
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/xattr.h>
+#include <linux/posix_acl.h>
#include "overlayfs.h"
static int ovl_copy_up_truncate(struct dentry *dentry)
@@ -191,32 +192,44 @@ static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
return err;
}
-static bool ovl_is_private_xattr(const char *name)
+bool ovl_is_private_xattr(const char *name)
{
-#define OVL_XATTR_PRE_NAME OVL_XATTR_PREFIX "."
- return strncmp(name, OVL_XATTR_PRE_NAME,
- sizeof(OVL_XATTR_PRE_NAME) - 1) == 0;
+ return strncmp(name, OVL_XATTR_PREFIX,
+ sizeof(OVL_XATTR_PREFIX) - 1) == 0;
}
-int ovl_setxattr(struct dentry *dentry, struct inode *inode,
- const char *name, const void *value,
- size_t size, int flags)
+int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value,
+ size_t size, int flags)
{
int err;
- struct dentry *upperdentry;
+ struct path realpath;
+ enum ovl_path_type type = ovl_path_real(dentry, &realpath);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
+ if (!value && !OVL_TYPE_UPPER(type)) {
+ err = vfs_getxattr(realpath.dentry, name, NULL, 0);
+ if (err < 0)
+ goto out_drop_write;
+ }
+
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
- upperdentry = ovl_dentry_upper(dentry);
+ if (!OVL_TYPE_UPPER(type))
+ ovl_path_upper(dentry, &realpath);
+
old_cred = ovl_override_creds(dentry->d_sb);
- err = vfs_setxattr(upperdentry, name, value, size, flags);
+ if (value)
+ err = vfs_setxattr(realpath.dentry, name, value, size, flags);
+ else {
+ WARN_ON(flags != XATTR_REPLACE);
+ err = vfs_removexattr(realpath.dentry, name);
+ }
revert_creds(old_cred);
out_drop_write:
@@ -225,16 +238,13 @@ out:
return err;
}
-ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
- const char *name, void *value, size_t size)
+int ovl_xattr_get(struct dentry *dentry, const char *name,
+ void *value, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
const struct cred *old_cred;
- if (ovl_is_private_xattr(name))
- return -ENODATA;
-
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_getxattr(realdentry, name, value, size);
revert_creds(old_cred);
@@ -245,7 +255,8 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
- int off;
+ size_t len;
+ char *s;
const struct cred *old_cred;
old_cred = ovl_override_creds(dentry->d_sb);
@@ -255,73 +266,39 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
return res;
/* filter out private xattrs */
- for (off = 0; off < res;) {
- char *s = list + off;
- size_t slen = strlen(s) + 1;
+ for (s = list, len = res; len;) {
+ size_t slen = strnlen(s, len) + 1;
- BUG_ON(off + slen > res);
+ /* underlying fs providing us with an broken xattr list? */
+ if (WARN_ON(slen > len))
+ return -EIO;
+ len -= slen;
if (ovl_is_private_xattr(s)) {
res -= slen;
- memmove(s, s + slen, res - off);
+ memmove(s, s + slen, len);
} else {
- off += slen;
+ s += slen;
}
}
return res;
}
-int ovl_removexattr(struct dentry *dentry, const char *name)
-{
- int err;
- struct path realpath;
- enum ovl_path_type type = ovl_path_real(dentry, &realpath);
- const struct cred *old_cred;
-
- err = ovl_want_write(dentry);
- if (err)
- goto out;
-
- err = -ENODATA;
- if (ovl_is_private_xattr(name))
- goto out_drop_write;
-
- if (!OVL_TYPE_UPPER(type)) {
- err = vfs_getxattr(realpath.dentry, name, NULL, 0);
- if (err < 0)
- goto out_drop_write;
-
- err = ovl_copy_up(dentry);
- if (err)
- goto out_drop_write;
-
- ovl_path_upper(dentry, &realpath);
- }
-
- old_cred = ovl_override_creds(dentry->d_sb);
- err = vfs_removexattr(realpath.dentry, name);
- revert_creds(old_cred);
-out_drop_write:
- ovl_drop_write(dentry);
-out:
- return err;
-}
-
struct posix_acl *ovl_get_acl(struct inode *inode, int type)
{
struct inode *realinode = ovl_inode_real(inode, NULL);
const struct cred *old_cred;
struct posix_acl *acl;
- if (!IS_POSIXACL(realinode))
+ if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode))
return NULL;
if (!realinode->i_op->get_acl)
return NULL;
old_cred = ovl_override_creds(inode->i_sb);
- acl = realinode->i_op->get_acl(realinode, type);
+ acl = get_acl(realinode, type);
revert_creds(old_cred);
return acl;
@@ -391,9 +368,9 @@ static const struct inode_operations ovl_file_inode_operations = {
.permission = ovl_permission,
.getattr = ovl_getattr,
.setxattr = generic_setxattr,
- .getxattr = ovl_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = ovl_listxattr,
- .removexattr = ovl_removexattr,
+ .removexattr = generic_removexattr,
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
};
@@ -404,9 +381,9 @@ static const struct inode_operations ovl_symlink_inode_operations = {
.readlink = ovl_readlink,
.getattr = ovl_getattr,
.setxattr = generic_setxattr,
- .getxattr = ovl_getxattr,
+ .getxattr = generic_getxattr,
.listxattr = ovl_listxattr,
- .removexattr = ovl_removexattr,
+ .removexattr = generic_removexattr,
.update_time = ovl_update_time,
};
@@ -415,6 +392,9 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode)
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_flags |= S_NOCMTIME;
+#ifdef CONFIG_FS_POSIX_ACL
+ inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
+#endif
mode &= S_IFMT;
switch (mode) {