diff options
Diffstat (limited to 'fs/namei.c')
-rw-r--r-- | fs/namei.c | 466 |
1 files changed, 270 insertions, 196 deletions
diff --git a/fs/namei.c b/fs/namei.c index 4b491b431990..40663e2d130c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -34,6 +34,7 @@ #include <linux/device_cgroup.h> #include <linux/fs_struct.h> #include <linux/posix_acl.h> +#include <linux/hash.h> #include <asm/uaccess.h> #include "internal.h" @@ -332,10 +333,11 @@ int generic_permission(struct inode *inode, int mask) if (S_ISDIR(inode->i_mode)) { /* DACs are overridable for directories */ - if (inode_capable(inode, CAP_DAC_OVERRIDE)) + if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE)) return 0; if (!(mask & MAY_WRITE)) - if (inode_capable(inode, CAP_DAC_READ_SEARCH)) + if (capable_wrt_inode_uidgid(inode, + CAP_DAC_READ_SEARCH)) return 0; return -EACCES; } @@ -345,7 +347,7 @@ int generic_permission(struct inode *inode, int mask) * at least one exec bit set. */ if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO)) - if (inode_capable(inode, CAP_DAC_OVERRIDE)) + if (capable_wrt_inode_uidgid(inode, CAP_DAC_OVERRIDE)) return 0; /* @@ -353,7 +355,7 @@ int generic_permission(struct inode *inode, int mask) */ mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (mask == MAY_READ) - if (inode_capable(inode, CAP_DAC_READ_SEARCH)) + if (capable_wrt_inode_uidgid(inode, CAP_DAC_READ_SEARCH)) return 0; return -EACCES; @@ -413,6 +415,7 @@ int __inode_permission(struct inode *inode, int mask) return security_inode_permission(inode, mask); } +EXPORT_SYMBOL(__inode_permission); /** * sb_permission - Check superblock-level permissions @@ -482,6 +485,24 @@ void path_put(const struct path *path) } EXPORT_SYMBOL(path_put); +/** + * path_connected - Verify that a path->dentry is below path->mnt.mnt_root + * @path: nameidate to verify + * + * Rename can sometimes move a file or directory outside of a bind + * mount, path_connected allows those cases to be detected. + */ +static bool path_connected(const struct path *path) +{ + struct vfsmount *mnt = path->mnt; + + /* Only bind mounts can have disconnected paths */ + if (mnt->mnt_root == mnt->mnt_sb->s_root) + return true; + + return is_subdir(path->dentry, mnt->mnt_root); +} + /* * Path walking has 2 modes, rcu-walk and ref-walk (see * Documentation/filesystems/path-lookup.txt). In situations when we can't @@ -640,24 +661,22 @@ static int complete_walk(struct nameidata *nd) static __always_inline void set_root(struct nameidata *nd) { - if (!nd->root.mnt) - get_fs_root(current->fs, &nd->root); + get_fs_root(current->fs, &nd->root); } static int link_path_walk(const char *, struct nameidata *); -static __always_inline void set_root_rcu(struct nameidata *nd) +static __always_inline unsigned set_root_rcu(struct nameidata *nd) { - if (!nd->root.mnt) { - struct fs_struct *fs = current->fs; - unsigned seq; + struct fs_struct *fs = current->fs; + unsigned seq, res; - do { - seq = read_seqcount_begin(&fs->seq); - nd->root = fs->root; - nd->seq = __read_seqcount_begin(&nd->root.dentry->d_seq); - } while (read_seqcount_retry(&fs->seq, seq)); - } + do { + seq = read_seqcount_begin(&fs->seq); + nd->root = fs->root; + res = __read_seqcount_begin(&nd->root.dentry->d_seq); + } while (read_seqcount_retry(&fs->seq, seq)); + return res; } static void path_put_conditional(struct path *path, struct nameidata *nd) @@ -857,7 +876,8 @@ follow_link(struct path *link, struct nameidata *nd, void **p) return PTR_ERR(s); } if (*s == '/') { - set_root(nd); + if (!nd->root.mnt) + set_root(nd); path_put(&nd->path); nd->path = nd->root; path_get(&nd->root); @@ -1130,7 +1150,8 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, static int follow_dotdot_rcu(struct nameidata *nd) { - set_root_rcu(nd); + if (!nd->root.mnt) + set_root_rcu(nd); while (1) { if (nd->path.dentry == nd->root.dentry && @@ -1147,6 +1168,8 @@ static int follow_dotdot_rcu(struct nameidata *nd) goto failed; nd->path.dentry = parent; nd->seq = seq; + if (unlikely(!path_connected(&nd->path))) + goto failed; break; } if (!follow_up_rcu(&nd->path)) @@ -1240,9 +1263,10 @@ static void follow_mount(struct path *path) } } -static void follow_dotdot(struct nameidata *nd) +static int follow_dotdot(struct nameidata *nd) { - set_root(nd); + if (!nd->root.mnt) + set_root(nd); while(1) { struct dentry *old = nd->path.dentry; @@ -1255,6 +1279,10 @@ static void follow_dotdot(struct nameidata *nd) /* rare case of legitimate dget_parent()... */ nd->path.dentry = dget_parent(nd->path.dentry); dput(old); + if (unlikely(!path_connected(&nd->path))) { + path_put(&nd->path); + return -ENOENT; + } break; } if (!follow_up(&nd->path)) @@ -1262,6 +1290,7 @@ static void follow_dotdot(struct nameidata *nd) } follow_mount(&nd->path); nd->inode = nd->path.dentry->d_inode; + return 0; } /* @@ -1485,7 +1514,7 @@ static inline int handle_dots(struct nameidata *nd, int type) if (follow_dotdot_rcu(nd)) return -ECHILD; } else - follow_dotdot(nd); + return follow_dotdot(nd); } return 0; } @@ -1537,12 +1566,13 @@ static inline int walk_component(struct nameidata *nd, struct path *path, inode = path->dentry->d_inode; } err = -ENOENT; - if (!inode) + if (!inode || d_is_negative(path->dentry)) goto out_path_put; if (should_follow_link(path->dentry, follow)) { if (nd->flags & LOOKUP_RCU) { - if (unlikely(unlazy_walk(nd, path->dentry))) { + if (unlikely(nd->path.mnt != path->mnt || + unlazy_walk(nd, path->dentry))) { err = -ECHILD; goto out_err; } @@ -1623,8 +1653,7 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd) static inline unsigned int fold_hash(unsigned long hash) { - hash += hash >> (8*sizeof(int)); - return hash; + return hash_64(hash, 32); } #else /* 32-bit case */ @@ -1796,7 +1825,7 @@ static int link_path_walk(const char *name, struct nameidata *nd) if (err) return err; } - if (!d_is_directory(nd->path.dentry)) { + if (!d_can_lookup(nd->path.dentry)) { err = -ENOTDIR; break; } @@ -1817,7 +1846,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, struct dentry *root = nd->root.dentry; struct inode *inode = root->d_inode; if (*name) { - if (!d_is_directory(root)) + if (!d_can_lookup(root)) return -ENOTDIR; retval = inode_permission(inode, MAY_EXEC); if (retval) @@ -1841,7 +1870,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, if (*name=='/') { if (flags & LOOKUP_RCU) { rcu_read_lock(); - set_root_rcu(nd); + nd->seq = set_root_rcu(nd); } else { set_root(nd); path_get(&nd->root); @@ -1873,7 +1902,7 @@ static int path_init(int dfd, const char *name, unsigned int flags, dentry = f.file->f_path.dentry; if (*name) { - if (!d_is_directory(dentry)) { + if (!d_can_lookup(dentry)) { fdput(f); return -ENOTDIR; } @@ -1955,7 +1984,7 @@ static int path_lookupat(int dfd, const char *name, err = complete_walk(nd); if (!err && nd->flags & LOOKUP_DIRECTORY) { - if (!d_is_directory(nd->path.dentry)) { + if (!d_can_lookup(nd->path.dentry)) { path_put(&nd->path); err = -ENOTDIR; } @@ -2211,7 +2240,7 @@ mountpoint_last(struct nameidata *nd, struct path *path) if (unlikely(nd->last_type != LAST_NORM)) { error = handle_dots(nd, nd->last_type); if (error) - goto out; + return error; dentry = dget(nd->path.dentry); goto done; } @@ -2240,15 +2269,16 @@ mountpoint_last(struct nameidata *nd, struct path *path) mutex_unlock(&dir->d_inode->i_mutex); done: - if (!dentry->d_inode) { + if (!dentry->d_inode || d_is_negative(dentry)) { error = -ENOENT; dput(dentry); goto out; } path->dentry = dentry; - path->mnt = mntget(nd->path.mnt); + path->mnt = nd->path.mnt; if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW)) return 1; + mntget(path->mnt); follow_mount(path); error = 0; out: @@ -2356,22 +2386,17 @@ kern_path_mountpoint(int dfd, const char *name, struct path *path, } EXPORT_SYMBOL(kern_path_mountpoint); -/* - * It's inline, so penalty for filesystems that don't use sticky bit is - * minimal. - */ -static inline int check_sticky(struct inode *dir, struct inode *inode) +int __check_sticky(struct inode *dir, struct inode *inode) { kuid_t fsuid = current_fsuid(); - if (!(dir->i_mode & S_ISVTX)) - return 0; if (uid_eq(inode->i_uid, fsuid)) return 0; if (uid_eq(dir->i_uid, fsuid)) return 0; - return !inode_capable(inode, CAP_FOWNER); + return !capable_wrt_inode_uidgid(inode, CAP_FOWNER); } +EXPORT_SYMBOL(__check_sticky); /* * Check whether we can remove a link victim from directory dir, check @@ -2414,11 +2439,11 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) return -EPERM; if (isdir) { - if (!d_is_directory(victim) && !d_is_autodir(victim)) + if (!d_is_dir(victim)) return -ENOTDIR; if (IS_ROOT(victim)) return -EBUSY; - } else if (d_is_directory(victim) || d_is_autodir(victim)) + } else if (d_is_dir(victim)) return -EISDIR; if (IS_DEADDIR(dir)) return -ENOENT; @@ -2474,7 +2499,7 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) } mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT2); return NULL; } @@ -2982,14 +3007,15 @@ retry_lookup: finish_lookup: /* we _can_ be in RCU mode here */ error = -ENOENT; - if (d_is_negative(path->dentry)) { + if (!inode || d_is_negative(path->dentry)) { path_to_nameidata(path, nd); goto out; } if (should_follow_link(path->dentry, !symlink_ok)) { if (nd->flags & LOOKUP_RCU) { - if (unlikely(unlazy_walk(nd, path->dentry))) { + if (unlikely(nd->path.mnt != path->mnt || + unlazy_walk(nd, path->dentry))) { error = -ECHILD; goto out; } @@ -3016,11 +3042,10 @@ finish_open: } audit_inode(name, nd->path.dentry, 0); error = -EISDIR; - if ((open_flag & O_CREAT) && - (d_is_directory(nd->path.dentry) || d_is_autodir(nd->path.dentry))) + if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry)) goto out; error = -ENOTDIR; - if ((nd->flags & LOOKUP_DIRECTORY) && !d_is_directory(nd->path.dentry)) + if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry)) goto out; if (!S_ISREG(nd->inode->i_mode)) will_truncate = false; @@ -3035,9 +3060,12 @@ finish_open_created: error = may_open(&nd->path, acc_mode, open_flag); if (error) goto out; - file->f_path.mnt = nd->path.mnt; - error = finish_open(file, nd->path.dentry, NULL, opened); - if (error) { + + BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ + error = vfs_open(&nd->path, file, current_cred()); + if (!error) { + *opened |= FILE_OPENED; + } else { if (error == -EOPENSTALE) goto stale_open; goto out; @@ -3126,7 +3154,8 @@ static int do_tmpfile(int dfd, struct filename *pathname, if (error) goto out2; audit_inode(pathname, nd->path.dentry, 0); - error = may_open(&nd->path, op->acc_mode, op->open_flag); + /* Don't check for other permissions, the inode was just created */ + error = may_open(&nd->path, MAY_OPEN, op->open_flag); if (error) goto out2; file->f_path.mnt = nd->path.mnt; @@ -3166,7 +3195,7 @@ static struct file *path_openat(int dfd, struct filename *pathname, if (unlikely(file->f_flags & __O_TMPFILE)) { error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened); - goto out; + goto out2; } error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base); @@ -3204,6 +3233,7 @@ out: path_put(&nd->root); if (base) fput(base); +out2: if (!(opened & FILE_OPENED)) { BUG_ON(!error); put_filp(file); @@ -3744,7 +3774,7 @@ exit1: slashes: if (d_is_negative(dentry)) error = -ENOENT; - else if (d_is_directory(dentry) || d_is_autodir(dentry)) + else if (d_is_dir(dentry)) error = -EISDIR; else error = -ENOTDIR; @@ -3974,7 +4004,28 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -/* +/** + * vfs_rename - rename a filesystem object + * @old_dir: parent of source + * @old_dentry: source + * @new_dir: parent of destination + * @new_dentry: destination + * @delegated_inode: returns an inode needing a delegation break + * @flags: rename flags + * + * The caller must hold multiple mutexes--see lock_rename()). + * + * If vfs_rename discovers a delegation in need of breaking at either + * the source or destination, it will return -EWOULDBLOCK and return a + * reference to the inode in delegated_inode. The caller should then + * break the delegation and retry. Because breaking a delegation may + * take a long time, the caller should drop all locks before doing + * so. + * + * Alternatively, a caller may pass NULL for delegated_inode. This may + * be appropriate for callers that expect the underlying filesystem not + * to be NFS exported. + * * The worst of all namespace operations - renaming directory. "Perverted" * doesn't even start to describe it. Somebody in UCB had a heck of a trip... * Problems: @@ -4002,163 +4053,140 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ -static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode, unsigned int flags) { - int error = 0; + int error; + bool is_dir = d_is_dir(old_dentry); + const unsigned char *old_name; + struct inode *source = old_dentry->d_inode; struct inode *target = new_dentry->d_inode; + bool new_is_dir = false; unsigned max_links = new_dir->i_sb->s_max_links; + if (source == target) + return 0; + + error = may_delete(old_dir, old_dentry, is_dir); + if (error) + return error; + + if (!target) { + error = may_create(new_dir, new_dentry); + } else { + new_is_dir = d_is_dir(new_dentry); + + if (!(flags & RENAME_EXCHANGE)) + error = may_delete(new_dir, new_dentry, is_dir); + else + error = may_delete(new_dir, new_dentry, new_is_dir); + } + if (error) + return error; + + if (!old_dir->i_op->rename && !old_dir->i_op->rename2) + return -EPERM; + + if (flags && !old_dir->i_op->rename2) + return -EINVAL; + /* * If we are going to change the parent - check write permissions, * we'll need to flip '..'. */ if (new_dir != old_dir) { - error = inode_permission(old_dentry->d_inode, MAY_WRITE); - if (error) - return error; + if (is_dir) { + error = inode_permission(source, MAY_WRITE); + if (error) + return error; + } + if ((flags & RENAME_EXCHANGE) && new_is_dir) { + error = inode_permission(target, MAY_WRITE); + if (error) + return error; + } } - error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); + error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry, + flags); if (error) return error; + old_name = fsnotify_oldname_init(old_dentry->d_name.name); dget(new_dentry); - if (target) + if (!is_dir || (flags & RENAME_EXCHANGE)) + lock_two_nondirectories(source, target); + else if (target) mutex_lock(&target->i_mutex); error = -EBUSY; if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry)) goto out; - error = -EMLINK; - if (max_links && !target && new_dir != old_dir && - new_dir->i_nlink >= max_links) - goto out; - - if (target) + if (max_links && new_dir != old_dir) { + error = -EMLINK; + if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links) + goto out; + if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir && + old_dir->i_nlink >= max_links) + goto out; + } + if (is_dir && !(flags & RENAME_EXCHANGE) && target) shrink_dcache_parent(new_dentry); - error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - goto out; - - if (target) { - target->i_flags |= S_DEAD; - dont_mount(new_dentry); + if (!is_dir) { + error = try_break_deleg(source, delegated_inode); + if (error) + goto out; } -out: - if (target) - mutex_unlock(&target->i_mutex); - dput(new_dentry); - if (!error) - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) - d_move(old_dentry,new_dentry); - return error; -} - -static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - struct inode *target = new_dentry->d_inode; - struct inode *source = old_dentry->d_inode; - int error; - - error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry); - if (error) - return error; - - dget(new_dentry); - lock_two_nondirectories(source, target); - - error = -EBUSY; - if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) - goto out; - - error = try_break_deleg(source, delegated_inode); - if (error) - goto out; - if (target) { + if (target && !new_is_dir) { error = try_break_deleg(target, delegated_inode); if (error) goto out; } - error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); + if (!old_dir->i_op->rename2) { + error = old_dir->i_op->rename(old_dir, old_dentry, + new_dir, new_dentry); + } else { + WARN_ON(old_dir->i_op->rename != NULL); + error = old_dir->i_op->rename2(old_dir, old_dentry, + new_dir, new_dentry, flags); + } if (error) goto out; - if (target) + if (!(flags & RENAME_EXCHANGE) && target) { + if (is_dir) + target->i_flags |= S_DEAD; dont_mount(new_dentry); - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) - d_move(old_dentry, new_dentry); + } + if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) { + if (!(flags & RENAME_EXCHANGE)) + d_move(old_dentry, new_dentry); + else + d_exchange(old_dentry, new_dentry); + } out: - unlock_two_nondirectories(source, target); + if (!is_dir || (flags & RENAME_EXCHANGE)) + unlock_two_nondirectories(source, target); + else if (target) + mutex_unlock(&target->i_mutex); dput(new_dentry); - return error; -} - -/** - * vfs_rename - rename a filesystem object - * @old_dir: parent of source - * @old_dentry: source - * @new_dir: parent of destination - * @new_dentry: destination - * @delegated_inode: returns an inode needing a delegation break - * - * The caller must hold multiple mutexes--see lock_rename()). - * - * If vfs_rename discovers a delegation in need of breaking at either - * the source or destination, it will return -EWOULDBLOCK and return a - * reference to the inode in delegated_inode. The caller should then - * break the delegation and retry. Because breaking a delegation may - * take a long time, the caller should drop all locks before doing - * so. - * - * Alternatively, a caller may pass NULL for delegated_inode. This may - * be appropriate for callers that expect the underlying filesystem not - * to be NFS exported. - */ -int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry, - struct inode **delegated_inode) -{ - int error; - int is_dir = d_is_directory(old_dentry) || d_is_autodir(old_dentry); - const unsigned char *old_name; - - if (old_dentry->d_inode == new_dentry->d_inode) - return 0; - - error = may_delete(old_dir, old_dentry, is_dir); - if (error) - return error; - - if (!new_dentry->d_inode) - error = may_create(new_dir, new_dentry); - else - error = may_delete(new_dir, new_dentry, is_dir); - if (error) - return error; - - if (!old_dir->i_op->rename) - return -EPERM; - - old_name = fsnotify_oldname_init(old_dentry->d_name.name); - - if (is_dir) - error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); - else - error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry,delegated_inode); - if (!error) + if (!error) { fsnotify_move(old_dir, new_dir, old_name, is_dir, - new_dentry->d_inode, old_dentry); + !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry); + if (flags & RENAME_EXCHANGE) { + fsnotify_move(new_dir, old_dir, old_dentry->d_name.name, + new_is_dir, NULL, new_dentry); + } + } fsnotify_oldname_free(old_name); return error; } -SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, - int, newdfd, const char __user *, newname) +SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, unsigned int, flags) { struct dentry *old_dir, *new_dir; struct dentry *old_dentry, *new_dentry; @@ -4170,6 +4198,17 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, unsigned int lookup_flags = 0; bool should_retry = false; int error; + + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) + return -EINVAL; + + if ((flags & (RENAME_NOREPLACE | RENAME_WHITEOUT)) && + (flags & RENAME_EXCHANGE)) + return -EINVAL; + + if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD)) + return -EPERM; + retry: from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags); if (IS_ERR(from)) { @@ -4193,6 +4232,8 @@ retry: goto exit2; new_dir = newnd.path.dentry; + if (flags & RENAME_NOREPLACE) + error = -EEXIST; if (newnd.last_type != LAST_NORM) goto exit2; @@ -4202,7 +4243,8 @@ retry: oldnd.flags &= ~LOOKUP_PARENT; newnd.flags &= ~LOOKUP_PARENT; - newnd.flags |= LOOKUP_RENAME_TARGET; + if (!(flags & RENAME_EXCHANGE)) + newnd.flags |= LOOKUP_RENAME_TARGET; retry_deleg: trap = lock_rename(new_dir, old_dir); @@ -4215,34 +4257,49 @@ retry_deleg: error = -ENOENT; if (d_is_negative(old_dentry)) goto exit4; + new_dentry = lookup_hash(&newnd); + error = PTR_ERR(new_dentry); + if (IS_ERR(new_dentry)) + goto exit4; + error = -EEXIST; + if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry)) + goto exit5; + if (flags & RENAME_EXCHANGE) { + error = -ENOENT; + if (d_is_negative(new_dentry)) + goto exit5; + + if (!d_is_dir(new_dentry)) { + error = -ENOTDIR; + if (newnd.last.name[newnd.last.len]) + goto exit5; + } + } /* unless the source is a directory trailing slashes give -ENOTDIR */ - if (!d_is_directory(old_dentry) && !d_is_autodir(old_dentry)) { + if (!d_is_dir(old_dentry)) { error = -ENOTDIR; if (oldnd.last.name[oldnd.last.len]) - goto exit4; - if (newnd.last.name[newnd.last.len]) - goto exit4; + goto exit5; + if (!(flags & RENAME_EXCHANGE) && newnd.last.name[newnd.last.len]) + goto exit5; } /* source should not be ancestor of target */ error = -EINVAL; if (old_dentry == trap) - goto exit4; - new_dentry = lookup_hash(&newnd); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) - goto exit4; + goto exit5; /* target should not be an ancestor of source */ - error = -ENOTEMPTY; + if (!(flags & RENAME_EXCHANGE)) + error = -ENOTEMPTY; if (new_dentry == trap) goto exit5; error = security_path_rename(&oldnd.path, old_dentry, - &newnd.path, new_dentry); + &newnd.path, new_dentry, flags); if (error) goto exit5; error = vfs_rename(old_dir->d_inode, old_dentry, - new_dir->d_inode, new_dentry, - &delegated_inode); + new_dir->d_inode, new_dentry, + &delegated_inode, flags); exit5: dput(new_dentry); exit4: @@ -4272,16 +4329,34 @@ exit: return error; } +SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname) +{ + return sys_renameat2(olddfd, oldname, newdfd, newname, 0); +} + SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) { - return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); + return sys_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link) +int vfs_whiteout(struct inode *dir, struct dentry *dentry) { - int len; + int error = may_create(dir, dentry); + if (error) + return error; - len = PTR_ERR(link); + if (!dir->i_op->mknod) + return -EPERM; + + return dir->i_op->mknod(dir, dentry, + S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); +} +EXPORT_SYMBOL(vfs_whiteout); + +int readlink_copy(char __user *buffer, int buflen, const char *link) +{ + int len = PTR_ERR(link); if (IS_ERR(link)) goto out; @@ -4293,6 +4368,7 @@ int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const c out: return len; } +EXPORT_SYMBOL(readlink_copy); /* * A helper for ->readlink(). This should be used *ONLY* for symlinks that @@ -4310,7 +4386,7 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) if (IS_ERR(cookie)) return PTR_ERR(cookie); - res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); + res = readlink_copy(buffer, buflen, nd_get_link(&nd)); if (dentry->d_inode->i_op->put_link) dentry->d_inode->i_op->put_link(dentry, &nd, cookie); return res; @@ -4334,8 +4410,7 @@ static char *page_getlink(struct dentry * dentry, struct page **ppage) int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) { struct page *page = NULL; - char *s = page_getlink(dentry, &page); - int res = vfs_readlink(dentry,buffer,buflen,s); + int res = readlink_copy(buffer, buflen, page_getlink(dentry, &page)); if (page) { kunmap(page); page_cache_release(page); @@ -4431,7 +4506,6 @@ EXPORT_SYMBOL(vfs_link); EXPORT_SYMBOL(vfs_mkdir); EXPORT_SYMBOL(vfs_mknod); EXPORT_SYMBOL(generic_permission); -EXPORT_SYMBOL(vfs_readlink); EXPORT_SYMBOL(vfs_rename); EXPORT_SYMBOL(vfs_rmdir); EXPORT_SYMBOL(vfs_symlink); |