diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 128 |
1 files changed, 58 insertions, 70 deletions
diff --git a/fs/namei.c b/fs/namei.c index ed8b9488a890..921ae32dbc80 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -391,50 +391,6 @@ static inline int do_inode_permission(struct inode *inode, int mask) } /** - * __inode_permission - Check for access rights to a given inode - * @inode: Inode to check permission on - * @mask: Right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) - * - * Check for read/write/execute permissions on an inode. - * - * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask. - * - * This does not check for a read-only file system. You probably want - * inode_permission(). - */ -int __inode_permission(struct inode *inode, int mask) -{ - int retval; - - if (unlikely(mask & MAY_WRITE)) { - /* - * Nobody gets write access to an immutable file. - */ - if (IS_IMMUTABLE(inode)) - return -EPERM; - - /* - * Updating mtime will likely cause i_uid and i_gid to be - * written back improperly if their true value is unknown - * to the vfs. - */ - if (HAS_UNMAPPED_ID(inode)) - return -EACCES; - } - - retval = do_inode_permission(inode, mask); - if (retval) - return retval; - - retval = devcgroup_inode_permission(inode, mask); - if (retval) - return retval; - - return security_inode_permission(inode, mask); -} -EXPORT_SYMBOL(__inode_permission); - -/** * sb_permission - Check superblock-level permissions * @sb: Superblock of inode to check permission on * @inode: Inode to check permission on @@ -472,7 +428,32 @@ int inode_permission(struct inode *inode, int mask) retval = sb_permission(inode->i_sb, inode, mask); if (retval) return retval; - return __inode_permission(inode, mask); + + if (unlikely(mask & MAY_WRITE)) { + /* + * Nobody gets write access to an immutable file. + */ + if (IS_IMMUTABLE(inode)) + return -EPERM; + + /* + * Updating mtime will likely cause i_uid and i_gid to be + * written back improperly if their true value is unknown + * to the vfs. + */ + if (HAS_UNMAPPED_ID(inode)) + return -EACCES; + } + + retval = do_inode_permission(inode, mask); + if (retval) + return retval; + + retval = devcgroup_inode_permission(inode, mask); + if (retval) + return retval; + + return security_inode_permission(inode, mask); } EXPORT_SYMBOL(inode_permission); @@ -1129,21 +1110,9 @@ static int follow_automount(struct path *path, struct nameidata *nd, * of the daemon to instantiate them before they can be used. */ if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY | - LOOKUP_OPEN | LOOKUP_CREATE | - LOOKUP_AUTOMOUNT))) { - /* Positive dentry that isn't meant to trigger an - * automount, EISDIR will allow it to be used, - * otherwise there's no mount here "now" so return - * ENOENT. - */ - if (path->dentry->d_inode) - return -EISDIR; - else - return -ENOENT; - } - - if (path->dentry->d_sb->s_user_ns != &init_user_ns) - return -EACCES; + LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) && + path->dentry->d_inode) + return -EISDIR; nd->total_link_count++; if (nd->total_link_count >= 40) @@ -1210,7 +1179,7 @@ static int follow_managed(struct path *path, struct nameidata *nd) /* Given that we're not holding a lock here, we retain the value in a * local variable for each dentry as we look at it so that we don't see * the components of that value change under us */ - while (managed = ACCESS_ONCE(path->dentry->d_flags), + while (managed = READ_ONCE(path->dentry->d_flags), managed &= DCACHE_MANAGED_DENTRY, unlikely(managed != 0)) { /* Allow the filesystem to manage the transit without i_mutex @@ -1395,7 +1364,7 @@ int follow_down(struct path *path) unsigned managed; int ret; - while (managed = ACCESS_ONCE(path->dentry->d_flags), + while (managed = READ_ONCE(path->dentry->d_flags), unlikely(managed & DCACHE_MANAGED_DENTRY)) { /* Allow the filesystem to manage the transit without i_mutex * being held. @@ -2907,6 +2876,27 @@ int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, } EXPORT_SYMBOL(vfs_create); +int vfs_mkobj(struct dentry *dentry, umode_t mode, + int (*f)(struct dentry *, umode_t, void *), + void *arg) +{ + struct inode *dir = dentry->d_parent->d_inode; + int error = may_create(dir, dentry); + if (error) + return error; + + mode &= S_IALLUGO; + mode |= S_IFREG; + error = security_inode_create(dir, dentry, mode); + if (error) + return error; + error = f(dentry, mode, arg); + if (!error) + fsnotify_create(dir, dentry); + return error; +} +EXPORT_SYMBOL(vfs_mkobj); + bool may_open_dev(const struct path *path) { return !(path->mnt->mnt_flags & MNT_NODEV) && @@ -3459,7 +3449,7 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, goto out; child = vfs_tmpfile(path.dentry, op->mode, op->open_flag); error = PTR_ERR(child); - if (unlikely(IS_ERR(child))) + if (IS_ERR(child)) goto out2; dput(path.dentry); path.dentry = child; @@ -4010,10 +4000,9 @@ EXPORT_SYMBOL(vfs_unlink); * writeout happening, and we don't want to prevent access to the directory * while waiting on the I/O. */ -static long do_unlinkat(int dfd, const char __user *pathname) +long do_unlinkat(int dfd, struct filename *name) { int error; - struct filename *name; struct dentry *dentry; struct path path; struct qstr last; @@ -4022,8 +4011,7 @@ static long do_unlinkat(int dfd, const char __user *pathname) struct inode *delegated_inode = NULL; unsigned int lookup_flags = 0; retry: - name = filename_parentat(dfd, getname(pathname), lookup_flags, - &path, &last, &type); + name = filename_parentat(dfd, name, lookup_flags, &path, &last, &type); if (IS_ERR(name)) return PTR_ERR(name); @@ -4065,12 +4053,12 @@ exit2: mnt_drop_write(path.mnt); exit1: path_put(&path); - putname(name); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; inode = NULL; goto retry; } + putname(name); return error; slashes: @@ -4091,12 +4079,12 @@ SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag) if (flag & AT_REMOVEDIR) return do_rmdir(dfd, pathname); - return do_unlinkat(dfd, pathname); + return do_unlinkat(dfd, getname(pathname)); } SYSCALL_DEFINE1(unlink, const char __user *, pathname) { - return do_unlinkat(AT_FDCWD, pathname); + return do_unlinkat(AT_FDCWD, getname(pathname)); } int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) |