diff options
Diffstat (limited to 'fs/overlayfs/inode.c')
| -rw-r--r-- | fs/overlayfs/inode.c | 108 |
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) { |