X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Fnamei.c;h=9714ca54c1bf89858e34ad6c12de409867b63967;hb=refs%2Fheads%2Fvserver;hp=763e9584024112354e1027b816bdff1f9b807e81;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git diff --git a/fs/namei.c b/fs/namei.c index 763e95840..9714ca54c 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -21,14 +21,22 @@ #include #include #include -#include +#include #include #include #include +#include #include #include +#include +#include +#include +#include +#include +#include #include - +#include +#include #include #include @@ -101,7 +109,7 @@ */ /* * [Sep 2001 AV] Single-semaphore locking scheme (kudos to David Holland) - * implemented. Let's see if raised priority of ->s_vfs_rename_sem gives + * implemented. Let's see if raised priority of ->s_vfs_rename_mutex gives * any extra contention... */ @@ -112,18 +120,19 @@ * POSIX.1 2.4: an empty pathname is invalid (ENOENT). * PATH_MAX includes the nul terminator --RR. */ -static inline int do_getname(const char __user *filename, char *page) +static int do_getname(const char __user *filename, char *page) { int retval; unsigned long len = PATH_MAX; - if ((unsigned long) filename >= TASK_SIZE) { - if (!segment_eq(get_fs(), KERNEL_DS)) + if (!segment_eq(get_fs(), KERNEL_DS)) { + if ((unsigned long) filename >= TASK_SIZE) return -EFAULT; - } else if (TASK_SIZE - (unsigned long) filename < PATH_MAX) - len = TASK_SIZE - (unsigned long) filename; + if (TASK_SIZE - (unsigned long) filename < PATH_MAX) + len = TASK_SIZE - (unsigned long) filename; + } - retval = strncpy_from_user((char *)page, filename, len); + retval = strncpy_from_user(page, filename, len); if (retval > 0) { if (retval < len) return 0; @@ -148,45 +157,52 @@ char * getname(const char __user * filename) result = ERR_PTR(retval); } } - if (unlikely(current->audit_context) && !IS_ERR(result) && result) - audit_getname(result); + audit_getname(result); return result; } -/* - * vfs_permission() +#ifdef CONFIG_AUDITSYSCALL +void putname(const char *name) +{ + if (unlikely(!audit_dummy_context())) + audit_putname(name); + else + __putname(name); +} +EXPORT_SYMBOL(putname); +#endif + + +/** + * generic_permission - check for access rights on a Posix-like filesystem + * @inode: inode to check access rights for + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * @check_acl: optional callback to check for Posix ACLs * - * is used to check for read/write/execute permissions on a file. + * Used to check for read/write/execute permissions on a file. * We use "fsuid" for this, letting us set arbitrary permissions * for filesystem access without changing the "normal" uids which * are used for other things.. */ -int vfs_permission(struct inode * inode, int mask) +int generic_permission(struct inode *inode, int mask, + int (*check_acl)(struct inode *inode, int mask)) { umode_t mode = inode->i_mode; - if (IS_BARRIER(inode) && !vx_check(0, VX_ADMIN|VX_WATCH)) - return -EACCES; - - if (mask & MAY_WRITE) { - /* - * Nobody gets write access to a read-only fs. - */ - if (IS_RDONLY(inode) && - (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) - return -EROFS; - - /* - * Nobody gets write access to an immutable file. - */ - if (IS_IMMUTABLE(inode)) - return -EACCES; - } - if (current->fsuid == inode->i_uid) mode >>= 6; - else if (in_group_p(inode->i_gid)) - mode >>= 3; + else { + if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { + int error = check_acl(inode, mask); + if (error == -EACCES) + goto check_capabilities; + else if (error != -EAGAIN) + return error; + } + + if (in_group_p(inode->i_gid)) + mode >>= 3; + } /* * If the DACs are ok we don't need any capability check. @@ -194,6 +210,7 @@ int vfs_permission(struct inode * inode, int mask) if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask)) return 0; + check_capabilities: /* * Read/write DACs are always overridable. * Executable DACs are overridable if at least one exec bit is set. @@ -213,35 +230,108 @@ int vfs_permission(struct inode * inode, int mask) return -EACCES; } -static inline int xid_permission(struct inode *inode) +static inline int dx_barrier(struct inode *inode) +{ + if (IS_BARRIER(inode) && !vx_check(0, VS_ADMIN)) { + vxwprintk(1, "xid=%d did hit the barrier.", + vx_current_xid()); + return 1; + } + return 0; +} + +static inline int dx_permission(struct inode *inode, int mask, struct nameidata *nd) { - if (inode->i_xid == 0) + if (dx_barrier(inode)) + return -EACCES; + if (inode->i_tag == 0) return 0; - if (vx_check(inode->i_xid, VX_ADMIN|VX_WATCH|VX_IDENT)) + if (dx_check(inode->i_tag, DX_ADMIN|DX_WATCH|DX_IDENT)) return 0; + + vxwprintk(1, "xid=%d denied access to %p[#%d,%lu] »%s«.", + vx_current_xid(), inode, inode->i_tag, inode->i_ino, + vxd_cond_path(nd)); return -EACCES; } -int permission(struct inode * inode,int mask, struct nameidata *nd) +int permission(struct inode *inode, int mask, struct nameidata *nd) { - int retval; - int submask; + umode_t mode = inode->i_mode; + int retval, submask; + + if (mask & MAY_WRITE) { + + /* + * Nobody gets write access to a read-only fs. + */ + if ((IS_RDONLY(inode) || (nd && MNT_IS_RDONLY(nd->mnt))) && + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) + return -EROFS; + + /* + * Nobody gets write access to an immutable file. + */ + if (IS_IMMUTABLE(inode) && !IS_COW(inode)) + return -EACCES; + } + + + /* + * MAY_EXEC on regular files requires special handling: We override + * filesystem execute permissions if the mode bits aren't set or + * the fs is mounted with the "noexec" flag. + */ + if ((mask & MAY_EXEC) && S_ISREG(mode) && (!(mode & S_IXUGO) || + (nd && nd->mnt && (nd->mnt->mnt_flags & MNT_NOEXEC)))) + return -EACCES; /* Ordinary permission routines do not understand MAY_APPEND. */ submask = mask & ~MAY_APPEND; - - if ((retval = xid_permission(inode))) + if ((retval = dx_permission(inode, mask, nd))) return retval; if (inode->i_op && inode->i_op->permission) retval = inode->i_op->permission(inode, submask, nd); else - retval = vfs_permission(inode, submask); + retval = generic_permission(inode, submask, NULL); if (retval) return retval; return security_inode_permission(inode, mask, nd); } +/** + * vfs_permission - check for access rights to a given path + * @nd: lookup result that describes the path + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on a path. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things. + */ +int vfs_permission(struct nameidata *nd, int mask) +{ + return permission(nd->dentry->d_inode, mask, nd); +} + +/** + * file_permission - check for additional access rights to a given file + * @file: file to check access rights for + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on an already opened + * file. + * + * Note: + * Do not use this function in new code. All access checks should + * be done using vfs_permission(). + */ +int file_permission(struct file *file, int mask) +{ + return permission(file->f_path.dentry->d_inode, mask, NULL); +} + /* * get_write_access() gets write permission for a file. * put_write_access() releases this write permission. @@ -275,7 +365,7 @@ int get_write_access(struct inode * inode) int deny_write_access(struct file * file) { - struct inode *inode = file->f_dentry->d_inode; + struct inode *inode = file->f_path.dentry->d_inode; spin_lock(&inode->i_lock); if (atomic_read(&inode->i_writecount) > 0) { @@ -294,6 +384,52 @@ void path_release(struct nameidata *nd) mntput(nd->mnt); } +/* + * umount() mustn't call path_release()/mntput() as that would clear + * mnt_expiry_mark + */ +void path_release_on_umount(struct nameidata *nd) +{ + dput(nd->dentry); + mntput_no_expire(nd->mnt); +} + +/** + * release_open_intent - free up open intent resources + * @nd: pointer to nameidata + */ +void release_open_intent(struct nameidata *nd) +{ + if (nd->intent.open.file->f_path.dentry == NULL) + put_filp(nd->intent.open.file); + else + fput(nd->intent.open.file); +} + +static inline struct dentry * +do_revalidate(struct dentry *dentry, struct nameidata *nd) +{ + int status = dentry->d_op->d_revalidate(dentry, nd); + if (unlikely(status <= 0)) { + /* + * The dentry failed validation. + * If d_revalidate returned 0 attempt to invalidate + * the dentry otherwise d_revalidate is asking us + * to return a fail status. + */ + if (!status) { + if (!d_invalidate(dentry)) { + dput(dentry); + dentry = NULL; + } + } else { + dput(dentry); + dentry = ERR_PTR(status); + } + } + return dentry; +} + /* * Internal lookup() using the new generic dcache. * SMP-safe @@ -308,31 +444,30 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, if (!dentry) dentry = d_lookup(parent, name); - if (dentry && dentry->d_op && dentry->d_op->d_revalidate) { - if (!dentry->d_op->d_revalidate(dentry, nd) && !d_invalidate(dentry)) { - dput(dentry); - dentry = NULL; - } - } + if (dentry && dentry->d_op && dentry->d_op->d_revalidate) + dentry = do_revalidate(dentry, nd); + return dentry; } /* * Short-cut version of permission(), for calling by * path_walk(), when dcache lock is held. Combines parts - * of permission() and vfs_permission(), and tests ONLY for + * of permission() and generic_permission(), and tests ONLY for * MAY_EXEC permission. * * If appropriate, check DAC only. If not appropriate, or * short-cut DAC fails, then call permission() to do more * complete permission check. */ -static inline int exec_permission_lite(struct inode *inode, +static int exec_permission_lite(struct inode *inode, struct nameidata *nd) { umode_t mode = inode->i_mode; - if ((inode->i_op && inode->i_op->permission)) + if (dx_barrier(inode)) + return -EACCES; + if (inode->i_op && inode->i_op->permission) return -EAGAIN; if (current->fsuid == inode->i_uid) @@ -346,6 +481,9 @@ static inline int exec_permission_lite(struct inode *inode, if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE)) goto ok; + if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE)) + goto ok; + if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH)) goto ok; @@ -367,7 +505,7 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s struct dentry * result; struct inode *dir = parent->d_inode; - down(&dir->i_sem); + mutex_lock(&dir->i_mutex); /* * First re-do the cached lookup just in case it was created * while we waited for the directory semaphore.. @@ -393,7 +531,7 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s else result = dentry; } - up(&dir->i_sem); + mutex_unlock(&dir->i_mutex); return result; } @@ -401,16 +539,119 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s * Uhhuh! Nasty case: the cache was re-populated while * we waited on the semaphore. Need to revalidate. */ - up(&dir->i_sem); + mutex_unlock(&dir->i_mutex); if (result->d_op && result->d_op->d_revalidate) { - if (!result->d_op->d_revalidate(result, nd) && !d_invalidate(result)) { - dput(result); + result = do_revalidate(result, nd); + if (!result) result = ERR_PTR(-ENOENT); - } } return result; } +static int __emul_lookup_dentry(const char *, struct nameidata *); + +/* SMP-safe */ +static __always_inline int +walk_init_root(const char *name, struct nameidata *nd) +{ + struct fs_struct *fs = current->fs; + + read_lock(&fs->lock); + if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) { + nd->mnt = mntget(fs->altrootmnt); + nd->dentry = dget(fs->altroot); + read_unlock(&fs->lock); + if (__emul_lookup_dentry(name,nd)) + return 0; + read_lock(&fs->lock); + } + nd->mnt = mntget(fs->rootmnt); + nd->dentry = dget(fs->root); + read_unlock(&fs->lock); + return 1; +} + +static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) +{ + int res = 0; + char *name; + if (IS_ERR(link)) + goto fail; + + if (*link == '/') { + path_release(nd); + if (!walk_init_root(link, nd)) + /* weird __emul_prefix() stuff did it */ + goto out; + } + res = link_path_walk(link, nd); +out: + if (nd->depth || res || nd->last_type!=LAST_NORM) + return res; + /* + * If it is an iterative symlinks resolution in open_namei() we + * have to copy the last component. And all that crap because of + * bloody create() on broken symlinks. Furrfu... + */ + name = __getname(); + if (unlikely(!name)) { + path_release(nd); + return -ENOMEM; + } + strcpy(name, nd->last.name); + nd->last.name = name; + return 0; +fail: + path_release(nd); + return PTR_ERR(link); +} + +static inline void dput_path(struct path *path, struct nameidata *nd) +{ + dput(path->dentry); + if (path->mnt != nd->mnt) + mntput(path->mnt); +} + +static inline void path_to_nameidata(struct path *path, struct nameidata *nd) +{ + dput(nd->dentry); + if (nd->mnt != path->mnt) + mntput(nd->mnt); + nd->mnt = path->mnt; + nd->dentry = path->dentry; +} + +static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd) +{ + int error; + void *cookie; + struct dentry *dentry = path->dentry; + + touch_atime(path->mnt, dentry); + nd_set_link(nd, NULL); + + if (path->mnt != nd->mnt) { + path_to_nameidata(path, nd); + dget(dentry); + } + mntget(path->mnt); + cookie = dentry->d_inode->i_op->follow_link(dentry, nd); + error = PTR_ERR(cookie); + if (!IS_ERR(cookie)) { + char *s = nd_get_link(nd); + error = 0; + if (s) + error = __vfs_follow_link(nd, s); + if (dentry->d_inode->i_op->put_link) + dentry->d_inode->i_op->put_link(dentry, nd, cookie); + } + dput(dentry); + mntput(path->mnt); + + return error; +} + /* * This limits recursive symlink follows to 8, while * limiting consecutive symlinks to 40. @@ -418,24 +659,27 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s * Without that kind of total limit, nasty chains of consecutive * symlinks can cause almost arbitrarily long lookups. */ -static inline int do_follow_link(struct dentry *dentry, struct nameidata *nd) +static inline int do_follow_link(struct path *path, struct nameidata *nd) { int err = -ELOOP; - if (current->link_count >= 5) + if (current->link_count >= MAX_NESTED_LINKS) goto loop; if (current->total_link_count >= 40) goto loop; + BUG_ON(nd->depth >= MAX_NESTED_LINKS); cond_resched(); - err = security_inode_follow_link(dentry, nd); + err = security_inode_follow_link(path->dentry, nd); if (err) goto loop; current->link_count++; current->total_link_count++; - touch_atime(nd->mnt, dentry); - err = dentry->d_inode->i_op->follow_link(dentry, nd); + nd->depth++; + err = __do_follow_link(path, nd); current->link_count--; + nd->depth--; return err; loop: + dput_path(path, nd); path_release(nd); return err; } @@ -463,87 +707,94 @@ int follow_up(struct vfsmount **mnt, struct dentry **dentry) /* no need for dcache_lock, as serialization is taken care in * namespace.c */ -static int follow_mount(struct vfsmount **mnt, struct dentry **dentry) +static int __follow_mount(struct path *path) { int res = 0; + while (d_mountpoint(path->dentry)) { + struct vfsmount *mounted = lookup_mnt(path->mnt, path->dentry); + if (!mounted) + break; + dput(path->dentry); + if (res) + mntput(path->mnt); + path->mnt = mounted; + path->dentry = dget(mounted->mnt_root); + res = 1; + } + return res; +} + +static void follow_mount(struct vfsmount **mnt, struct dentry **dentry) +{ while (d_mountpoint(*dentry)) { struct vfsmount *mounted = lookup_mnt(*mnt, *dentry); if (!mounted) break; + dput(*dentry); mntput(*mnt); *mnt = mounted; - dput(*dentry); *dentry = dget(mounted->mnt_root); - res = 1; } - return res; } /* no need for dcache_lock, as serialization is taken care in * namespace.c */ -static inline int __follow_down(struct vfsmount **mnt, struct dentry **dentry) +int follow_down(struct vfsmount **mnt, struct dentry **dentry) { struct vfsmount *mounted; mounted = lookup_mnt(*mnt, *dentry); if (mounted) { + dput(*dentry); mntput(*mnt); *mnt = mounted; - dput(*dentry); *dentry = dget(mounted->mnt_root); return 1; } return 0; } -int follow_down(struct vfsmount **mnt, struct dentry **dentry) -{ - return __follow_down(mnt,dentry); -} - -static inline void follow_dotdot(struct vfsmount **mnt, struct dentry **dentry) +static __always_inline void follow_dotdot(struct nameidata *nd) { + struct fs_struct *fs = current->fs; + while(1) { struct vfsmount *parent; - struct dentry *old = *dentry; - - read_lock(¤t->fs->lock); - if (*dentry == current->fs->root && - *mnt == current->fs->rootmnt) { - read_unlock(¤t->fs->lock); - break; + struct dentry *old = nd->dentry; + + read_lock(&fs->lock); + if (nd->dentry == fs->root && + nd->mnt == fs->rootmnt) { + read_unlock(&fs->lock); + /* for sane '/' avoid follow_mount() */ + return; } - read_unlock(¤t->fs->lock); + read_unlock(&fs->lock); spin_lock(&dcache_lock); - if (*dentry != (*mnt)->mnt_root) { - *dentry = dget((*dentry)->d_parent); + if (nd->dentry != nd->mnt->mnt_root) { + nd->dentry = dget(nd->dentry->d_parent); spin_unlock(&dcache_lock); dput(old); break; } spin_unlock(&dcache_lock); spin_lock(&vfsmount_lock); - parent = (*mnt)->mnt_parent; - if (parent == *mnt) { + parent = nd->mnt->mnt_parent; + if (parent == nd->mnt) { spin_unlock(&vfsmount_lock); break; } mntget(parent); - *dentry = dget((*mnt)->mnt_mountpoint); + nd->dentry = dget(nd->mnt->mnt_mountpoint); spin_unlock(&vfsmount_lock); dput(old); - mntput(*mnt); - *mnt = parent; + mntput(nd->mnt); + nd->mnt = parent; } - follow_mount(mnt, dentry); + follow_mount(&nd->mnt, &nd->dentry); } -struct path { - struct vfsmount *mnt; - struct dentry *dentry; -}; - /* * It's more convoluted than I'd like it to be, but... it's still fairly * small and for now I'd prefer to have fast path as straight as possible. @@ -554,15 +805,34 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, { struct vfsmount *mnt = nd->mnt; struct dentry *dentry = __d_lookup(nd->dentry, name); + struct inode *inode; if (!dentry) goto need_lookup; if (dentry->d_op && dentry->d_op->d_revalidate) goto need_revalidate; + inode = dentry->d_inode; + if (!inode) + goto done; + if (inode->i_sb->s_magic == PROC_SUPER_MAGIC) { + struct proc_dir_entry *de = PDE(inode); + + if (de && !vx_hide_check(0, de->vx_flags)) + goto hidden; + } + if (!dx_check(inode->i_tag, DX_WATCH|DX_ADMIN|DX_HOSTID|DX_IDENT)) + goto hidden; done: path->mnt = mnt; path->dentry = dentry; + __follow_mount(path); return 0; +hidden: + vxwprintk(1, "xid=%d did lookup hidden %p[#%d,%lu] »%s«.", + vx_current_xid(), inode, inode->i_tag, inode->i_ino, + vxd_path(dentry, mnt)); + dput(dentry); + return -ENOENT; need_lookup: dentry = real_lookup(nd->dentry, name, nd); @@ -571,12 +841,12 @@ need_lookup: goto done; need_revalidate: - if (dentry->d_op->d_revalidate(dentry, nd)) - goto done; - if (d_invalidate(dentry)) - goto done; - dput(dentry); - goto need_lookup; + dentry = do_revalidate(dentry, nd); + if (!dentry) + goto need_lookup; + if (IS_ERR(dentry)) + goto fail; + goto done; fail: return PTR_ERR(dentry); @@ -584,13 +854,13 @@ fail: /* * Name resolution. + * This is the basic name resolution function, turning a pathname into + * the final dentry. We expect 'base' to be positive and a directory. * - * This is the basic name resolution function, turning a pathname - * into the final dentry. - * - * We expect 'base' to be positive and a directory. + * Returns 0 and nd will have valid dentry and mnt on success. + * Returns error and drops reference to input namei data on failure. */ -int fastcall link_path_walk(const char * name, struct nameidata *nd) +static fastcall int __link_path_walk(const char * name, struct nameidata *nd) { struct path next; struct inode *inode; @@ -603,8 +873,8 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) goto return_reval; inode = nd->dentry->d_inode; - if (current->link_count) - lookup_flags = LOOKUP_FOLLOW; + if (nd->depth) + lookup_flags = LOOKUP_FOLLOW | (nd->flags & LOOKUP_CONTINUE); /* At this point we know we have a real path component. */ for(;;) { @@ -612,10 +882,10 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) struct qstr this; unsigned int c; + nd->flags |= LOOKUP_CONTINUE; err = exec_permission_lite(inode, nd); - if (err == -EAGAIN) { - err = permission(inode, MAY_EXEC, nd); - } + if (err == -EAGAIN) + err = vfs_permission(nd, MAY_EXEC); if (err) break; @@ -649,7 +919,7 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) case 2: if (this.name[1] != '.') break; - follow_dotdot(&nd->mnt, &nd->dentry); + follow_dotdot(nd); inode = nd->dentry->d_inode; /* fallthrough */ case 1: @@ -664,13 +934,10 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) if (err < 0) break; } - nd->flags |= LOOKUP_CONTINUE; /* This does the actual lookups.. */ err = do_lookup(nd, &this, &next); if (err) break; - /* Check mountpoints.. */ - follow_mount(&next.mnt, &next.dentry); err = -ENOENT; inode = next.dentry->d_inode; @@ -681,10 +948,7 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) goto out_dput; if (inode->i_op->follow_link) { - mntget(next.mnt); - err = do_follow_link(next.dentry, nd); - dput(next.dentry); - mntput(next.mnt); + err = do_follow_link(&next, nd); if (err) goto return_err; err = -ENOENT; @@ -694,11 +958,8 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) err = -ENOTDIR; if (!inode->i_op) break; - } else { - dput(nd->dentry); - nd->mnt = next.mnt; - nd->dentry = next.dentry; - } + } else + path_to_nameidata(&next, nd); err = -ENOTDIR; if (!inode->i_op->lookup) break; @@ -708,7 +969,8 @@ int fastcall link_path_walk(const char * name, struct nameidata *nd) last_with_slashes: lookup_flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; last_component: - nd->flags &= ~LOOKUP_CONTINUE; + /* Clear LOOKUP_CONTINUE iff it was previously unset */ + nd->flags &= lookup_flags | ~LOOKUP_CONTINUE; if (lookup_flags & LOOKUP_PARENT) goto lookup_parent; if (this.name[0] == '.') switch (this.len) { @@ -717,7 +979,7 @@ last_component: case 2: if (this.name[1] != '.') break; - follow_dotdot(&nd->mnt, &nd->dentry); + follow_dotdot(nd); inode = nd->dentry->d_inode; /* fallthrough */ case 1: @@ -731,22 +993,15 @@ last_component: err = do_lookup(nd, &this, &next); if (err) break; - follow_mount(&next.mnt, &next.dentry); inode = next.dentry->d_inode; if ((lookup_flags & LOOKUP_FOLLOW) && inode && inode->i_op && inode->i_op->follow_link) { - mntget(next.mnt); - err = do_follow_link(next.dentry, nd); - dput(next.dentry); - mntput(next.mnt); + err = do_follow_link(&next, nd); if (err) goto return_err; inode = nd->dentry->d_inode; - } else { - dput(nd->dentry); - nd->mnt = next.mnt; - nd->dentry = next.dentry; - } + } else + path_to_nameidata(&next, nd); err = -ENOENT; if (!inode) break; @@ -782,7 +1037,7 @@ return_reval: return_base: return 0; out_dput: - dput(next.dentry); + dput_path(&next, nd); break; } path_release(nd); @@ -790,42 +1045,80 @@ return_err: return err; } +/* + * Wrapper to retry pathname resolution whenever the underlying + * file system returns an ESTALE. + * + * Retry the whole path once, forcing real lookup requests + * instead of relying on the dcache. + */ +int fastcall link_path_walk(const char *name, struct nameidata *nd) +{ + struct nameidata save = *nd; + int result; + + /* make sure the stuff we saved doesn't go away */ + dget(save.dentry); + mntget(save.mnt); + + result = __link_path_walk(name, nd); + if (result == -ESTALE) { + *nd = save; + dget(nd->dentry); + mntget(nd->mnt); + nd->flags |= LOOKUP_REVAL; + result = __link_path_walk(name, nd); + } + + dput(save.dentry); + mntput(save.mnt); + + return result; +} + int fastcall path_walk(const char * name, struct nameidata *nd) { current->total_link_count = 0; return link_path_walk(name, nd); } -/* SMP-safe */ -/* returns 1 if everything is done */ +/* + * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if + * everything is done. Returns 0 and drops input nd, if lookup failed; + */ static int __emul_lookup_dentry(const char *name, struct nameidata *nd) { if (path_walk(name, nd)) return 0; /* something went wrong... */ if (!nd->dentry->d_inode || S_ISDIR(nd->dentry->d_inode->i_mode)) { - struct nameidata nd_root; + struct dentry *old_dentry = nd->dentry; + struct vfsmount *old_mnt = nd->mnt; + struct qstr last = nd->last; + int last_type = nd->last_type; + struct fs_struct *fs = current->fs; + /* - * NAME was not found in alternate root or it's a directory. Try to find - * it in the normal root: + * NAME was not found in alternate root or it's a directory. + * Try to find it in the normal root: */ - nd_root.last_type = LAST_ROOT; - nd_root.flags = nd->flags; - memcpy(&nd_root.intent, &nd->intent, sizeof(nd_root.intent)); - read_lock(¤t->fs->lock); - nd_root.mnt = mntget(current->fs->rootmnt); - nd_root.dentry = dget(current->fs->root); - read_unlock(¤t->fs->lock); - if (path_walk(name, &nd_root)) - return 1; - if (nd_root.dentry->d_inode) { + nd->last_type = LAST_ROOT; + read_lock(&fs->lock); + nd->mnt = mntget(fs->rootmnt); + nd->dentry = dget(fs->root); + read_unlock(&fs->lock); + if (path_walk(name, nd) == 0) { + if (nd->dentry->d_inode) { + dput(old_dentry); + mntput(old_mnt); + return 1; + } path_release(nd); - nd->dentry = nd_root.dentry; - nd->mnt = nd_root.mnt; - nd->last = nd_root.last; - return 1; } - path_release(&nd_root); + nd->dentry = old_dentry; + nd->mnt = old_mnt; + nd->last = last; + nd->last_type = last_type; } return 1; } @@ -837,6 +1130,7 @@ void set_fs_altroot(void) struct vfsmount *mnt = NULL, *oldmnt; struct dentry *dentry = NULL, *olddentry; int err; + struct fs_struct *fs = current->fs; if (!emul) goto set_it; @@ -846,70 +1140,160 @@ void set_fs_altroot(void) dentry = nd.dentry; } set_it: - write_lock(¤t->fs->lock); - oldmnt = current->fs->altrootmnt; - olddentry = current->fs->altroot; - current->fs->altrootmnt = mnt; - current->fs->altroot = dentry; - write_unlock(¤t->fs->lock); + write_lock(&fs->lock); + oldmnt = fs->altrootmnt; + olddentry = fs->altroot; + fs->altrootmnt = mnt; + fs->altroot = dentry; + write_unlock(&fs->lock); if (olddentry) { dput(olddentry); mntput(oldmnt); } } -/* SMP-safe */ -static inline int -walk_init_root(const char *name, struct nameidata *nd) +/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ +static int fastcall do_path_lookup(int dfd, const char *name, + unsigned int flags, struct nameidata *nd) { - read_lock(¤t->fs->lock); - if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) { - nd->mnt = mntget(current->fs->altrootmnt); - nd->dentry = dget(current->fs->altroot); - read_unlock(¤t->fs->lock); - if (__emul_lookup_dentry(name,nd)) - return 0; - read_lock(¤t->fs->lock); + int retval = 0; + int fput_needed; + struct file *file; + struct fs_struct *fs = current->fs; + + nd->last_type = LAST_ROOT; /* if there are only slashes... */ + nd->flags = flags; + nd->depth = 0; + + if (*name=='/') { + read_lock(&fs->lock); + if (fs->altroot && !(nd->flags & LOOKUP_NOALT)) { + nd->mnt = mntget(fs->altrootmnt); + nd->dentry = dget(fs->altroot); + read_unlock(&fs->lock); + if (__emul_lookup_dentry(name,nd)) + goto out; /* found in altroot */ + read_lock(&fs->lock); + } + nd->mnt = mntget(fs->rootmnt); + nd->dentry = dget(fs->root); + read_unlock(&fs->lock); + } else if (dfd == AT_FDCWD) { + read_lock(&fs->lock); + nd->mnt = mntget(fs->pwdmnt); + nd->dentry = dget(fs->pwd); + read_unlock(&fs->lock); + } else { + struct dentry *dentry; + + file = fget_light(dfd, &fput_needed); + retval = -EBADF; + if (!file) + goto out_fail; + + dentry = file->f_path.dentry; + + retval = -ENOTDIR; + if (!S_ISDIR(dentry->d_inode->i_mode)) + goto fput_fail; + + retval = file_permission(file, MAY_EXEC); + if (retval) + goto fput_fail; + + nd->mnt = mntget(file->f_path.mnt); + nd->dentry = dget(dentry); + + fput_light(file, fput_needed); } - nd->mnt = mntget(current->fs->rootmnt); - nd->dentry = dget(current->fs->root); - read_unlock(¤t->fs->lock); - return 1; + current->total_link_count = 0; + retval = link_path_walk(name, nd); +out: + if (likely(retval == 0)) { + if (unlikely(!audit_dummy_context() && nd && nd->dentry && + nd->dentry->d_inode)) + audit_inode(name, nd->dentry->d_inode); + } +out_fail: + return retval; + +fput_fail: + fput_light(file, fput_needed); + goto out_fail; +} + +int fastcall path_lookup(const char *name, unsigned int flags, + struct nameidata *nd) +{ + return do_path_lookup(AT_FDCWD, name, flags, nd); +} + +static int __path_lookup_intent_open(int dfd, const char *name, + unsigned int lookup_flags, struct nameidata *nd, + int open_flags, int create_mode) +{ + struct file *filp = get_empty_filp(); + int err; + + if (filp == NULL) + return -ENFILE; + nd->intent.open.file = filp; + nd->intent.open.flags = open_flags; + nd->intent.open.create_mode = create_mode; + err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd); + if (IS_ERR(nd->intent.open.file)) { + if (err == 0) { + err = PTR_ERR(nd->intent.open.file); + path_release(nd); + } + } else if (err != 0) + release_open_intent(nd); + return err; +} + +/** + * path_lookup_open - lookup a file path with open intent + * @dfd: the directory to use as base, or AT_FDCWD + * @name: pointer to file name + * @lookup_flags: lookup intent flags + * @nd: pointer to nameidata + * @open_flags: open intent flags + */ +int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, + struct nameidata *nd, int open_flags) +{ + return __path_lookup_intent_open(dfd, name, lookup_flags, nd, + open_flags, 0); } -int fastcall path_lookup(const char *name, unsigned int flags, struct nameidata *nd) +/** + * path_lookup_create - lookup a file path with open + create intent + * @dfd: the directory to use as base, or AT_FDCWD + * @name: pointer to file name + * @lookup_flags: lookup intent flags + * @nd: pointer to nameidata + * @open_flags: open intent flags + * @create_mode: create intent flags + */ +static int path_lookup_create(int dfd, const char *name, + unsigned int lookup_flags, struct nameidata *nd, + int open_flags, int create_mode) { - int retval; + return __path_lookup_intent_open(dfd, name, lookup_flags|LOOKUP_CREATE, + nd, open_flags, create_mode); +} - nd->last_type = LAST_ROOT; /* if there are only slashes... */ - nd->flags = flags; +int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags, + struct nameidata *nd, int open_flags) +{ + char *tmp = getname(name); + int err = PTR_ERR(tmp); - read_lock(¤t->fs->lock); - if (*name=='/') { - if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) { - nd->mnt = mntget(current->fs->altrootmnt); - nd->dentry = dget(current->fs->altroot); - read_unlock(¤t->fs->lock); - if (__emul_lookup_dentry(name,nd)) - return 0; - read_lock(¤t->fs->lock); - } - nd->mnt = mntget(current->fs->rootmnt); - nd->dentry = dget(current->fs->root); - } - else{ - nd->mnt = mntget(current->fs->pwdmnt); - nd->dentry = dget(current->fs->pwd); + if (!IS_ERR(tmp)) { + err = __path_lookup_intent_open(AT_FDCWD, tmp, lookup_flags, nd, open_flags, 0); + putname(tmp); } - read_unlock(¤t->fs->lock); - current->total_link_count = 0; - retval = link_path_walk(name, nd); - if (unlikely(current->audit_context - && nd && nd->dentry && nd->dentry->d_inode)) - audit_inode(name, - nd->dentry->d_inode->i_ino, - nd->dentry->d_inode->i_rdev); - return retval; + return err; } /* @@ -956,9 +1340,9 @@ out: return dentry; } -struct dentry * lookup_hash(struct qstr *name, struct dentry * base) +static struct dentry *lookup_hash(struct nameidata *nd) { - return __lookup_hash(name, base, NULL); + return __lookup_hash(&nd->last, nd->dentry, nd); } /* SMP-safe */ @@ -982,7 +1366,7 @@ struct dentry * lookup_one_len(const char * name, struct dentry * base, int len) } this.hash = end_name_hash(hash); - return lookup_hash(&this, base); + return __lookup_hash(&this, base, NULL); access: return ERR_PTR(-EACCES); } @@ -998,18 +1382,24 @@ access: * that namei follows links, while lnamei does not. * SMP-safe */ -int fastcall __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) +int fastcall __user_walk_fd(int dfd, const char __user *name, unsigned flags, + struct nameidata *nd) { char *tmp = getname(name); int err = PTR_ERR(tmp); if (!IS_ERR(tmp)) { - err = path_lookup(tmp, flags, nd); + err = do_path_lookup(dfd, tmp, flags, nd); putname(tmp); } return err; } +int fastcall __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) +{ + return __user_walk_fd(AT_FDCWD, name, flags, nd); +} + /* * It's inline, so penalty for filesystems that don't use sticky bit is * minimal. @@ -1044,12 +1434,18 @@ static inline int check_sticky(struct inode *dir, struct inode *inode) * 10. We don't allow removal of NFS sillyrenamed files; it's handled by * nfs_async_unlink(). */ -static inline int may_delete(struct inode *dir,struct dentry *victim,int isdir) +static int may_delete(struct inode *dir, struct dentry *victim, + int isdir, struct nameidata *nd) { int error; - if (!victim->d_inode || victim->d_parent->d_inode != dir) + + if (!victim->d_inode) return -ENOENT; - error = permission(dir,MAY_WRITE | MAY_EXEC, NULL); + + BUG_ON(victim->d_parent->d_inode != dir); + audit_inode_child(victim->d_name.name, victim->d_inode, dir); + + error = permission(dir,MAY_WRITE | MAY_EXEC, nd); if (error) return error; if (IS_APPEND(dir)) @@ -1090,9 +1486,6 @@ static inline int may_create(struct inode *dir, struct dentry *child, } /* - * Special case: O_CREAT|O_EXCL implies O_NOFOLLOW for security - * reasons. - * * O_DIRECTORY translates into forcing a directory lookup. */ static inline int lookup_flags(unsigned int f) @@ -1102,9 +1495,6 @@ static inline int lookup_flags(unsigned int f) if (f & O_NOFOLLOW) retval &= ~LOOKUP_FOLLOW; - if ((f & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) - retval &= ~LOOKUP_FOLLOW; - if (f & O_DIRECTORY) retval |= LOOKUP_DIRECTORY; @@ -1119,39 +1509,39 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) struct dentry *p; if (p1 == p2) { - down(&p1->d_inode->i_sem); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); return NULL; } - down(&p1->d_inode->i_sb->s_vfs_rename_sem); + mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex); for (p = p1; p->d_parent != p; p = p->d_parent) { if (p->d_parent == p2) { - down(&p2->d_inode->i_sem); - down(&p1->d_inode->i_sem); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); return p; } } for (p = p2; p->d_parent != p; p = p->d_parent) { if (p->d_parent == p1) { - down(&p1->d_inode->i_sem); - down(&p2->d_inode->i_sem); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); return p; } } - down(&p1->d_inode->i_sem); - down(&p2->d_inode->i_sem); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); return NULL; } void unlock_rename(struct dentry *p1, struct dentry *p2) { - up(&p1->d_inode->i_sem); + mutex_unlock(&p1->d_inode->i_mutex); if (p1 != p2) { - up(&p2->d_inode->i_sem); - up(&p1->d_inode->i_sb->s_vfs_rename_sem); + mutex_unlock(&p2->d_inode->i_mutex); + mutex_unlock(&p1->d_inode->i_sb->s_vfs_rename_mutex); } } @@ -1172,10 +1562,8 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, return error; DQUOT_INIT(dir); error = dir->i_op->create(dir, dentry, mode, nd); - if (!error) { - inode_dir_notify(dir, DN_CREATE); - security_inode_post_create(dir, dentry, mode); - } + if (!error) + fsnotify_create(dir, dentry); return error; } @@ -1194,7 +1582,15 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (S_ISDIR(inode->i_mode) && (flag & FMODE_WRITE)) return -EISDIR; - error = permission(inode, acc_mode, nd); +#ifdef CONFIG_VSERVER_COWBL + if (IS_COW(inode) && (flag & FMODE_WRITE)) { + if (IS_COW_LINK(inode)) + return -EMLINK; + inode->i_flags &= ~(S_IUNLINK|S_IMMUTABLE); + mark_inode_dirty(inode); + } +#endif + error = vfs_permission(nd, acc_mode); if (error) return error; @@ -1210,7 +1606,8 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) return -EACCES; flag &= ~O_TRUNC; - } else if (IS_RDONLY(inode) && (flag & FMODE_WRITE)) + } else if ((IS_RDONLY(inode) || MNT_IS_RDONLY(nd->mnt)) + && (flag & FMODE_WRITE)) return -EROFS; /* * An append-only file must be opened in append mode for writing. @@ -1222,6 +1619,11 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) return -EPERM; } + /* O_NOATIME can only be set by the owner or superuser */ + if (flag & O_NOATIME) + if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER)) + return -EPERM; + /* * Ensure there are no outstanding leases on the file. */ @@ -1241,7 +1643,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (!error) { DQUOT_INIT(inode); - error = do_truncate(dentry, 0); + error = do_truncate(dentry, 0, ATTR_MTIME|ATTR_CTIME, NULL); } put_write_access(inode); if (error) @@ -1253,6 +1655,24 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) return 0; } +static int open_namei_create(struct nameidata *nd, struct path *path, + int flag, int mode) +{ + int error; + struct dentry *dir = nd->dentry; + + if (!IS_POSIXACL(dir->d_inode)) + mode &= ~current->fs->umask; + error = vfs_create(dir->d_inode, path->dentry, mode, nd); + mutex_unlock(&dir->d_inode->i_mutex); + dput(nd->dentry); + nd->dentry = path->dentry; + if (error) + return error; + /* Don't check for write permission, don't truncate */ + return may_open(nd, 0, flag & ~O_TRUNC); +} + /* * open_namei() * @@ -1267,29 +1687,36 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) * for symlinks (where the permissions are checked later). * SMP-safe */ -int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd) +int open_namei(int dfd, const char *pathname, int flag, + int mode, struct nameidata *nd) { - int acc_mode, error = 0; - struct dentry *dentry; + int acc_mode, error; + struct path path; struct dentry *dir; int count = 0; +#ifdef CONFIG_VSERVER_COWBL + int rflag = flag; + int rmode = mode; +restart: +#endif acc_mode = ACC_MODE(flag); + /* O_TRUNC implies we need access checks for write permissions */ + if (flag & O_TRUNC) + acc_mode |= MAY_WRITE; + /* Allow the LSM permission hook to distinguish append access from general write access. */ if (flag & O_APPEND) acc_mode |= MAY_APPEND; - /* Fill in the open() intent data */ - nd->intent.open.flags = flag; - nd->intent.open.create_mode = mode; - /* * The simplest case - just a plain lookup. */ if (!(flag & O_CREAT)) { - error = path_lookup(pathname, lookup_flags(flag)|LOOKUP_OPEN, nd); + error = path_lookup_open(dfd, pathname, lookup_flags(flag), + nd, flag); if (error) return error; goto ok; @@ -1298,7 +1725,7 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd) /* * Create - we need to know the parent. */ - error = path_lookup(pathname, LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE, nd); + error = path_lookup_create(dfd,pathname,LOOKUP_PARENT,nd,flag,mode); if (error) return error; @@ -1313,67 +1740,84 @@ int open_namei(const char * pathname, int flag, int mode, struct nameidata *nd) dir = nd->dentry; nd->flags &= ~LOOKUP_PARENT; - down(&dir->d_inode->i_sem); - dentry = __lookup_hash(&nd->last, nd->dentry, nd); + mutex_lock(&dir->d_inode->i_mutex); + path.dentry = lookup_hash(nd); + path.mnt = nd->mnt; do_last: - error = PTR_ERR(dentry); - if (IS_ERR(dentry)) { - up(&dir->d_inode->i_sem); + error = PTR_ERR(path.dentry); + if (IS_ERR(path.dentry)) { + mutex_unlock(&dir->d_inode->i_mutex); goto exit; } + if (IS_ERR(nd->intent.open.file)) { + mutex_unlock(&dir->d_inode->i_mutex); + error = PTR_ERR(nd->intent.open.file); + goto exit_dput; + } + /* Negative dentry, just create the file */ - if (!dentry->d_inode) { - if (!IS_POSIXACL(dir->d_inode)) - mode &= ~current->fs->umask; - error = vfs_create(dir->d_inode, dentry, mode, nd); - up(&dir->d_inode->i_sem); - dput(nd->dentry); - nd->dentry = dentry; + if (!path.dentry->d_inode) { + error = open_namei_create(nd, &path, flag, mode); if (error) goto exit; - /* Don't check for write permission, don't truncate */ - acc_mode = 0; - flag &= ~O_TRUNC; - goto ok; + return 0; } /* * It already exists. */ - up(&dir->d_inode->i_sem); + mutex_unlock(&dir->d_inode->i_mutex); + audit_inode_update(path.dentry->d_inode); error = -EEXIST; if (flag & O_EXCL) goto exit_dput; - if (d_mountpoint(dentry)) { + if (__follow_mount(&path)) { error = -ELOOP; if (flag & O_NOFOLLOW) goto exit_dput; - while (__follow_down(&nd->mnt,&dentry) && d_mountpoint(dentry)); } + error = -ENOENT; - if (!dentry->d_inode) + if (!path.dentry->d_inode) goto exit_dput; - if (dentry->d_inode->i_op && dentry->d_inode->i_op->follow_link) + if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link) goto do_link; - dput(nd->dentry); - nd->dentry = dentry; + path_to_nameidata(&path, nd); error = -EISDIR; - if (dentry->d_inode && S_ISDIR(dentry->d_inode->i_mode)) + if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode)) goto exit; ok: error = may_open(nd, acc_mode, flag); +#ifdef CONFIG_VSERVER_COWBL + if (error == -EMLINK) { + struct dentry *dentry; + dentry = cow_break_link(pathname); + if (IS_ERR(dentry)) { + error = PTR_ERR(dentry); + goto exit; + } + dput(dentry); + release_open_intent(nd); + path_release(nd); + flag = rflag; + mode = rmode; + goto restart; + } +#endif if (error) goto exit; return 0; exit_dput: - dput(dentry); + dput_path(&path, nd); exit: + if (!IS_ERR(nd->intent.open.file)) + release_open_intent(nd); path_release(nd); return error; @@ -1392,35 +1836,38 @@ do_link: * are done. Procfs-like symlinks just set LAST_BIND. */ nd->flags |= LOOKUP_PARENT; - error = security_inode_follow_link(dentry, nd); + error = security_inode_follow_link(path.dentry, nd); if (error) goto exit_dput; - touch_atime(nd->mnt, dentry); - error = dentry->d_inode->i_op->follow_link(dentry, nd); - dput(dentry); - if (error) + error = __do_follow_link(&path, nd); + if (error) { + /* Does someone understand code flow here? Or it is only + * me so stupid? Anathema to whoever designed this non-sense + * with "intent.open". + */ + release_open_intent(nd); return error; + } nd->flags &= ~LOOKUP_PARENT; - if (nd->last_type == LAST_BIND) { - dentry = nd->dentry; + if (nd->last_type == LAST_BIND) goto ok; - } error = -EISDIR; if (nd->last_type != LAST_NORM) goto exit; if (nd->last.name[nd->last.len]) { - putname(nd->last.name); + __putname(nd->last.name); goto exit; } error = -ELOOP; if (count++==32) { - putname(nd->last.name); + __putname(nd->last.name); goto exit; } dir = nd->dentry; - down(&dir->d_inode->i_sem); - dentry = __lookup_hash(&nd->last, nd->dentry, nd); - putname(nd->last.name); + mutex_lock(&dir->d_inode->i_mutex); + path.dentry = lookup_hash(nd); + path.mnt = nd->mnt; + __putname(nd->last.name); goto do_last; } @@ -1431,19 +1878,37 @@ do_link: * * Simple function to lookup and return a dentry and create it * if it doesn't exist. Is SMP-safe. + * + * Returns with nd->dentry->d_inode->i_mutex locked. */ struct dentry *lookup_create(struct nameidata *nd, int is_dir) { - struct dentry *dentry; + struct dentry *dentry = ERR_PTR(-EEXIST); - down(&nd->dentry->d_inode->i_sem); - dentry = ERR_PTR(-EEXIST); + mutex_lock_nested(&nd->dentry->d_inode->i_mutex, I_MUTEX_PARENT); + /* + * Yucky last component or no last component at all? + * (foo/., foo/.., /////) + */ if (nd->last_type != LAST_NORM) goto fail; nd->flags &= ~LOOKUP_PARENT; - dentry = lookup_hash(&nd->last, nd->dentry); + nd->flags |= LOOKUP_CREATE; + nd->intent.open.flags = O_EXCL; + + /* + * Do the final lookup. + */ + dentry = lookup_hash(nd); if (IS_ERR(dentry)) goto fail; + + /* + * Special case - lookup gave negative, but... we had foo/bar/ + * From the vfs_mknod() POV we just have a negative dentry - + * all is fine. Let's be bastards - you had / on the end, you've + * been asking for (non-existent) directory. -ENOENT for you. + */ if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode) goto enoent; return dentry; @@ -1453,10 +1918,12 @@ enoent: fail: return dentry; } +EXPORT_SYMBOL_GPL(lookup_create); -int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) +int vfs_mknod(struct inode *dir, struct dentry *dentry, + int mode, dev_t dev, struct nameidata *nd) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry, nd); if (error) return error; @@ -1473,14 +1940,13 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) DQUOT_INIT(dir); error = dir->i_op->mknod(dir, dentry, mode, dev); - if (!error) { - inode_dir_notify(dir, DN_CREATE); - security_inode_post_mknod(dir, dentry, mode, dev); - } + if (!error) + fsnotify_create(dir, dentry); return error; } -asmlinkage long sys_mknod(const char __user * filename, int mode, unsigned dev) +asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, + unsigned dev) { int error = 0; char * tmp; @@ -1493,7 +1959,7 @@ asmlinkage long sys_mknod(const char __user * filename, int mode, unsigned dev) if (IS_ERR(tmp)) return PTR_ERR(tmp); - error = path_lookup(tmp, LOOKUP_PARENT, &nd); + error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); if (error) goto out; dentry = lookup_create(&nd, 0); @@ -1507,11 +1973,12 @@ asmlinkage long sys_mknod(const char __user * filename, int mode, unsigned dev) error = vfs_create(nd.dentry->d_inode,dentry,mode,&nd); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode, - new_decode_dev(dev)); + error = vfs_mknod(nd.dentry->d_inode, dentry, mode, + new_decode_dev(dev), &nd); break; case S_IFIFO: case S_IFSOCK: - error = vfs_mknod(nd.dentry->d_inode,dentry,mode,0); + error = vfs_mknod(nd.dentry->d_inode, dentry, mode, + 0, &nd); break; case S_IFDIR: error = -EPERM; @@ -1521,7 +1988,7 @@ asmlinkage long sys_mknod(const char __user * filename, int mode, unsigned dev) } dput(dentry); } - up(&nd.dentry->d_inode->i_sem); + mutex_unlock(&nd.dentry->d_inode->i_mutex); path_release(&nd); out: putname(tmp); @@ -1529,9 +1996,15 @@ out: return error; } -int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) +asmlinkage long sys_mknod(const char __user *filename, int mode, unsigned dev) +{ + return sys_mknodat(AT_FDCWD, filename, mode, dev); +} + +int vfs_mkdir(struct inode *dir, struct dentry *dentry, + int mode, struct nameidata *nd) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry, nd); if (error) return error; @@ -1546,44 +2019,49 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) DQUOT_INIT(dir); error = dir->i_op->mkdir(dir, dentry, mode); - if (!error) { - inode_dir_notify(dir, DN_CREATE); - security_inode_post_mkdir(dir,dentry, mode); - } + if (!error) + fsnotify_mkdir(dir, dentry); return error; } -asmlinkage long sys_mkdir(const char __user * pathname, int mode) +asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) { int error = 0; char * tmp; + struct dentry *dentry; + struct nameidata nd; tmp = getname(pathname); error = PTR_ERR(tmp); - if (!IS_ERR(tmp)) { - struct dentry *dentry; - struct nameidata nd; + if (IS_ERR(tmp)) + goto out_err; - error = path_lookup(tmp, LOOKUP_PARENT, &nd); - if (error) - goto out; - dentry = lookup_create(&nd, 1); - error = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { - if (!IS_POSIXACL(nd.dentry->d_inode)) - mode &= ~current->fs->umask; - error = vfs_mkdir(nd.dentry->d_inode, dentry, mode); - dput(dentry); - } - up(&nd.dentry->d_inode->i_sem); - path_release(&nd); -out: - putname(tmp); - } + error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); + if (error) + goto out; + dentry = lookup_create(&nd, 1); + error = PTR_ERR(dentry); + if (IS_ERR(dentry)) + goto out_unlock; + if (!IS_POSIXACL(nd.dentry->d_inode)) + mode &= ~current->fs->umask; + error = vfs_mkdir(nd.dentry->d_inode, dentry, mode, &nd); + dput(dentry); +out_unlock: + mutex_unlock(&nd.dentry->d_inode->i_mutex); + path_release(&nd); +out: + putname(tmp); +out_err: return error; } +asmlinkage long sys_mkdir(const char __user *pathname, int mode) +{ + return sys_mkdirat(AT_FDCWD, pathname, mode); +} + /* * We try to drop the dentry early: we should have * a usage count of 2 if we're the only user of this @@ -1599,26 +2077,22 @@ out: * if it cannot handle the case of removing a directory * that is still in use by something else.. */ -static void d_unhash(struct dentry *dentry) +void dentry_unhash(struct dentry *dentry) { dget(dentry); + shrink_dcache_parent(dentry); spin_lock(&dcache_lock); - switch (atomic_read(&dentry->d_count)) { - default: - spin_unlock(&dcache_lock); - shrink_dcache_parent(dentry); - spin_lock(&dcache_lock); - if (atomic_read(&dentry->d_count) != 2) - break; - case 2: + spin_lock(&dentry->d_lock); + if (atomic_read(&dentry->d_count) == 2) __d_drop(dentry); - } + spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); } -int vfs_rmdir(struct inode *dir, struct dentry *dentry) +int vfs_rmdir(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) { - int error = may_delete(dir, dentry, 1); + int error = may_delete(dir, dentry, 1, nd); if (error) return error; @@ -1628,8 +2102,8 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) DQUOT_INIT(dir); - down(&dentry->d_inode->i_sem); - d_unhash(dentry); + mutex_lock(&dentry->d_inode->i_mutex); + dentry_unhash(dentry); if (d_mountpoint(dentry)) error = -EBUSY; else { @@ -1640,9 +2114,8 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) dentry->d_inode->i_flags |= S_DEAD; } } - up(&dentry->d_inode->i_sem); + mutex_unlock(&dentry->d_inode->i_mutex); if (!error) { - inode_dir_notify(dir, DN_DELETE); d_delete(dentry); } dput(dentry); @@ -1650,7 +2123,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) return error; } -asmlinkage long sys_rmdir(const char __user * pathname) +static long do_rmdir(int dfd, const char __user *pathname) { int error = 0; char * name; @@ -1661,7 +2134,7 @@ asmlinkage long sys_rmdir(const char __user * pathname) if(IS_ERR(name)) return PTR_ERR(name); - error = path_lookup(name, LOOKUP_PARENT, &nd); + error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); if (error) goto exit; @@ -1676,14 +2149,15 @@ asmlinkage long sys_rmdir(const char __user * pathname) error = -EBUSY; goto exit1; } - down(&nd.dentry->d_inode->i_sem); - dentry = lookup_hash(&nd.last, nd.dentry); + mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + dentry = lookup_hash(&nd); error = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { - error = vfs_rmdir(nd.dentry->d_inode, dentry); - dput(dentry); - } - up(&nd.dentry->d_inode->i_sem); + if (IS_ERR(dentry)) + goto exit2; + error = vfs_rmdir(nd.dentry->d_inode, dentry, &nd); + dput(dentry); +exit2: + mutex_unlock(&nd.dentry->d_inode->i_mutex); exit1: path_release(&nd); exit: @@ -1691,9 +2165,15 @@ exit: return error; } -int vfs_unlink(struct inode *dir, struct dentry *dentry) +asmlinkage long sys_rmdir(const char __user *pathname) { - int error = may_delete(dir, dentry, 0); + return do_rmdir(AT_FDCWD, pathname); +} + +int vfs_unlink(struct inode *dir, struct dentry *dentry, + struct nameidata *nd) +{ + int error = may_delete(dir, dentry, 0, nd); if (error) return error; @@ -1703,7 +2183,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) DQUOT_INIT(dir); - down(&dentry->d_inode->i_sem); + mutex_lock(&dentry->d_inode->i_mutex); if (d_mountpoint(dentry)) error = -EBUSY; else { @@ -1711,23 +2191,23 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) if (!error) error = dir->i_op->unlink(dir, dentry); } - up(&dentry->d_inode->i_sem); + mutex_unlock(&dentry->d_inode->i_mutex); /* We don't d_delete() NFS sillyrenamed files--they still exist. */ if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) { d_delete(dentry); - inode_dir_notify(dir, DN_DELETE); } + return error; } /* * Make sure that the actual truncation of the file will occur outside its - * directory's i_sem. Truncate can take a long time if there is a lot of + * directory's i_mutex. Truncate can take a long time if there is a lot of * writeout happening, and we don't want to prevent access to the directory * while waiting on the I/O. */ -asmlinkage long sys_unlink(const char __user * pathname) +static long do_unlinkat(int dfd, const char __user *pathname) { int error = 0; char * name; @@ -1739,14 +2219,14 @@ asmlinkage long sys_unlink(const char __user * pathname) if(IS_ERR(name)) return PTR_ERR(name); - error = path_lookup(name, LOOKUP_PARENT, &nd); + error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); if (error) goto exit; error = -EISDIR; if (nd.last_type != LAST_NORM) goto exit1; - down(&nd.dentry->d_inode->i_sem); - dentry = lookup_hash(&nd.last, nd.dentry); + mutex_lock_nested(&nd.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (!IS_ERR(dentry)) { /* Why not before? Because we want correct error value */ @@ -1755,18 +2235,17 @@ asmlinkage long sys_unlink(const char __user * pathname) inode = dentry->d_inode; if (inode) atomic_inc(&inode->i_count); - error = vfs_unlink(nd.dentry->d_inode, dentry); + error = vfs_unlink(nd.dentry->d_inode, dentry, &nd); exit2: dput(dentry); } - up(&nd.dentry->d_inode->i_sem); + mutex_unlock(&nd.dentry->d_inode->i_mutex); + if (inode) + iput(inode); /* truncate the inode here */ exit1: path_release(&nd); exit: putname(name); - - if (inode) - iput(inode); /* truncate the inode here */ return error; slashes: @@ -1775,9 +2254,26 @@ slashes: goto exit2; } -int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode) +asmlinkage long sys_unlinkat(int dfd, const char __user *pathname, int flag) +{ + if ((flag & ~AT_REMOVEDIR) != 0) + return -EINVAL; + + if (flag & AT_REMOVEDIR) + return do_rmdir(dfd, pathname); + + return do_unlinkat(dfd, pathname); +} + +asmlinkage long sys_unlink(const char __user *pathname) +{ + return do_unlinkat(AT_FDCWD, pathname); +} + +int vfs_symlink(struct inode *dir, struct dentry *dentry, + const char *oldname, int mode, struct nameidata *nd) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry, nd); if (error) return error; @@ -1791,47 +2287,55 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, i DQUOT_INIT(dir); error = dir->i_op->symlink(dir, dentry, oldname); - if (!error) { - inode_dir_notify(dir, DN_CREATE); - security_inode_post_symlink(dir, dentry, oldname); - } + if (!error) + fsnotify_create(dir, dentry); return error; } -asmlinkage long sys_symlink(const char __user * oldname, const char __user * newname) +asmlinkage long sys_symlinkat(const char __user *oldname, + int newdfd, const char __user *newname) { int error = 0; char * from; char * to; + struct dentry *dentry; + struct nameidata nd; from = getname(oldname); if(IS_ERR(from)) return PTR_ERR(from); to = getname(newname); error = PTR_ERR(to); - if (!IS_ERR(to)) { - struct dentry *dentry; - struct nameidata nd; + if (IS_ERR(to)) + goto out_putname; - error = path_lookup(to, LOOKUP_PARENT, &nd); - if (error) - goto out; - dentry = lookup_create(&nd, 0); - error = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { - error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO); - dput(dentry); - } - up(&nd.dentry->d_inode->i_sem); - path_release(&nd); + error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); + if (error) + goto out; + dentry = lookup_create(&nd, 0); + error = PTR_ERR(dentry); + if (IS_ERR(dentry)) + goto out_unlock; + + error = vfs_symlink(nd.dentry->d_inode, dentry, from, S_IALLUGO, &nd); + dput(dentry); +out_unlock: + mutex_unlock(&nd.dentry->d_inode->i_mutex); + path_release(&nd); out: - putname(to); - } + putname(to); +out_putname: putname(from); return error; } -int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) +asmlinkage long sys_symlink(const char __user *oldname, const char __user *newname) +{ + return sys_symlinkat(oldname, AT_FDCWD, newname); +} + +int vfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry, struct nameidata *nd) { struct inode *inode = old_dentry->d_inode; int error; @@ -1839,7 +2343,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry, NULL); + error = may_create(dir, new_dentry, nd); if (error) return error; @@ -1860,14 +2364,12 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (error) return error; - down(&old_dentry->d_inode->i_sem); + mutex_lock(&old_dentry->d_inode->i_mutex); DQUOT_INIT(dir); error = dir->i_op->link(old_dentry, dir, new_dentry); - up(&old_dentry->d_inode->i_sem); - if (!error) { - inode_dir_notify(dir, DN_CREATE); - security_inode_post_link(old_dentry, dir, new_dentry); - } + mutex_unlock(&old_dentry->d_inode->i_mutex); + if (!error) + fsnotify_create(dir, new_dentry); return error; } @@ -1880,21 +2382,28 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -asmlinkage long sys_link(const char __user * oldname, const char __user * newname) +asmlinkage long sys_linkat(int olddfd, const char __user *oldname, + int newdfd, const char __user *newname, + int flags) { struct dentry *new_dentry; struct nameidata nd, old_nd; int error; char * to; + if ((flags & ~AT_SYMLINK_FOLLOW) != 0) + return -EINVAL; + to = getname(newname); if (IS_ERR(to)) return PTR_ERR(to); - error = __user_walk(oldname, 0, &old_nd); + error = __user_walk_fd(olddfd, oldname, + flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, + &old_nd); if (error) goto exit; - error = path_lookup(to, LOOKUP_PARENT, &nd); + error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); if (error) goto out; error = -EXDEV; @@ -1902,11 +2411,12 @@ asmlinkage long sys_link(const char __user * oldname, const char __user * newnam goto out_release; new_dentry = lookup_create(&nd, 0); error = PTR_ERR(new_dentry); - if (!IS_ERR(new_dentry)) { - error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry); - dput(new_dentry); - } - up(&nd.dentry->d_inode->i_sem); + if (IS_ERR(new_dentry)) + goto out_unlock; + error = vfs_link(old_nd.dentry, nd.dentry->d_inode, new_dentry, &nd); + dput(new_dentry); +out_unlock: + mutex_unlock(&nd.dentry->d_inode->i_mutex); out_release: path_release(&nd); out: @@ -1917,6 +2427,11 @@ exit: return error; } +asmlinkage long sys_link(const char __user *oldname, const char __user *newname) +{ + return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); +} + /* * 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... @@ -1924,17 +2439,17 @@ exit: * a) we can get into loop creation. Check is done in is_subdir(). * b) race potential - two innocent renames can create a loop together. * That's where 4.4 screws up. Current fix: serialization on - * sb->s_vfs_rename_sem. We might be more accurate, but that's another + * sb->s_vfs_rename_mutex. We might be more accurate, but that's another * story. * c) we have to lock _three_ objects - parents and victim (if it exists). - * And that - after we got ->i_sem on parents (until then we don't know + * And that - after we got ->i_mutex on parents (until then we don't know * whether the target exists). Solution: try to be smart with locking * order for inodes. We rely on the fact that tree topology may change - * only under ->s_vfs_rename_sem _and_ that parent of the object we + * only under ->s_vfs_rename_mutex _and_ that parent of the object we * move will be locked. Thus we can rank directories by the tree * (ancestors first) and rank all non-directories after them. * That works since everybody except rename does "lock parent, lookup, - * lock child" and rename is under ->s_vfs_rename_sem. + * lock child" and rename is under ->s_vfs_rename_mutex. * HOWEVER, it relies on the assumption that any object with ->lookup() * has no more than 1 dentry. If "hybrid" objects will ever appear, * we'd better make sure that there's no link(2) for them. @@ -1944,13 +2459,13 @@ exit: * stuff into VFS), but the former is not going away. Solution: the same * trick as in rmdir(). * e) conversion from fhandle to dentry may come in the wrong moment - when - * we are removing the target. Solution: we will have to grab ->i_sem + * we are removing the target. Solution: we will have to grab ->i_mutex * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on - * ->i_sem on parents, which works but leads to some truely excessive + * ->i_mutex on parents, which works but leads to some truely excessive * locking]. */ -int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) { int error = 0; struct inode *target; @@ -1971,8 +2486,8 @@ int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, target = new_dentry->d_inode; if (target) { - down(&target->i_sem); - d_unhash(new_dentry); + mutex_lock(&target->i_mutex); + dentry_unhash(new_dentry); } if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) error = -EBUSY; @@ -1981,21 +2496,19 @@ int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, if (target) { if (!error) target->i_flags |= S_DEAD; - up(&target->i_sem); + mutex_unlock(&target->i_mutex); if (d_unhashed(new_dentry)) d_rehash(new_dentry); dput(new_dentry); } - if (!error) { - d_move(old_dentry,new_dentry); - security_inode_post_rename(old_dir, old_dentry, - new_dir, 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; } -int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) { struct inode *target; int error; @@ -2007,19 +2520,17 @@ int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, dget(new_dentry); target = new_dentry->d_inode; if (target) - down(&target->i_sem); + mutex_lock(&target->i_mutex); if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) error = -EBUSY; else error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); if (!error) { - /* The following d_move() should become unconditional */ - if (!(old_dir->i_sb->s_type->fs_flags & FS_ODD_RENAME)) + if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) d_move(old_dentry, new_dentry); - security_inode_post_rename(old_dir, old_dentry, new_dir, new_dentry); } if (target) - up(&target->i_sem); + mutex_unlock(&target->i_mutex); dput(new_dentry); return error; } @@ -2029,18 +2540,19 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, { int error; int is_dir = S_ISDIR(old_dentry->d_inode->i_mode); + const char *old_name; if (old_dentry->d_inode == new_dentry->d_inode) return 0; - error = may_delete(old_dir, old_dentry, is_dir); + error = may_delete(old_dir, old_dentry, is_dir, NULL); if (error) return error; if (!new_dentry->d_inode) error = may_create(new_dir, new_dentry, NULL); else - error = may_delete(new_dir, new_dentry, is_dir); + error = may_delete(new_dir, new_dentry, is_dir, NULL); if (error) return error; @@ -2050,22 +2562,24 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, DQUOT_INIT(old_dir); DQUOT_INIT(new_dir); + 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); if (!error) { - if (old_dir == new_dir) - inode_dir_notify(old_dir, DN_RENAME); - else { - inode_dir_notify(old_dir, DN_DELETE); - inode_dir_notify(new_dir, DN_CREATE); - } + const char *new_name = old_dentry->d_name.name; + fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir, + new_dentry->d_inode, old_dentry->d_inode); } + fsnotify_oldname_free(old_name); + return error; } -static inline int do_rename(const char * oldname, const char * newname) +static int do_rename(int olddfd, const char *oldname, + int newdfd, const char *newname) { int error = 0; struct dentry * old_dir, * new_dir; @@ -2073,11 +2587,11 @@ static inline int do_rename(const char * oldname, const char * newname) struct dentry * trap; struct nameidata oldnd, newnd; - error = path_lookup(oldname, LOOKUP_PARENT, &oldnd); + error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd); if (error) goto exit; - error = path_lookup(newname, LOOKUP_PARENT, &newnd); + error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd); if (error) goto exit1; @@ -2096,7 +2610,7 @@ static inline int do_rename(const char * oldname, const char * newname) trap = lock_rename(new_dir, old_dir); - old_dentry = lookup_hash(&oldnd.last, old_dir); + old_dentry = lookup_hash(&oldnd); error = PTR_ERR(old_dentry); if (IS_ERR(old_dentry)) goto exit3; @@ -2116,7 +2630,10 @@ static inline int do_rename(const char * oldname, const char * newname) error = -EINVAL; if (old_dentry == trap) goto exit4; - new_dentry = lookup_hash(&newnd.last, new_dir); + error = -EROFS; + if (MNT_IS_RDONLY(newnd.mnt)) + goto exit4; + new_dentry = lookup_hash(&newnd); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) goto exit4; @@ -2141,7 +2658,8 @@ exit: return error; } -asmlinkage long sys_rename(const char __user * oldname, const char __user * newname) +asmlinkage long sys_renameat(int olddfd, const char __user *oldname, + int newdfd, const char __user *newname) { int error; char * from; @@ -2153,13 +2671,18 @@ asmlinkage long sys_rename(const char __user * oldname, const char __user * newn to = getname(newname); error = PTR_ERR(to); if (!IS_ERR(to)) { - error = do_rename(from,to); + error = do_rename(olddfd, from, newdfd, to); putname(to); } putname(from); return error; } +asmlinkage long sys_rename(const char __user *oldname, const char __user *newname) +{ + return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); +} + int vfs_readlink(struct dentry *dentry, char __user *buffer, int buflen, const char *link) { int len; @@ -2177,40 +2700,25 @@ out: return len; } -static inline int -__vfs_follow_link(struct nameidata *nd, const char *link) +/* + * A helper for ->readlink(). This should be used *ONLY* for symlinks that + * have ->follow_link() touching nd only in nd_set_link(). Using (or not + * using) it for any given inode is up to filesystem. + */ +int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) { - int res = 0; - char *name; - if (IS_ERR(link)) - goto fail; + struct nameidata nd; + void *cookie; - if (*link == '/') { - path_release(nd); - if (!walk_init_root(link, nd)) - /* weird __emul_prefix() stuff did it */ - goto out; - } - res = link_path_walk(link, nd); -out: - if (current->link_count || res || nd->last_type!=LAST_NORM) - return res; - /* - * If it is an iterative symlinks resolution in open_namei() we - * have to copy the last component. And all that crap because of - * bloody create() on broken symlinks. Furrfu... - */ - name = __getname(); - if (unlikely(!name)) { - path_release(nd); - return -ENOMEM; + nd.depth = 0; + cookie = dentry->d_inode->i_op->follow_link(dentry, &nd); + if (!IS_ERR(cookie)) { + int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); + if (dentry->d_inode->i_op->put_link) + dentry->d_inode->i_op->put_link(dentry, &nd, cookie); + cookie = ERR_PTR(res); } - strcpy(name, nd->last.name); - nd->last.name = name; - return 0; -fail: - path_release(nd); - return PTR_ERR(link); + return PTR_ERR(cookie); } int vfs_follow_link(struct nameidata *nd, const char *link) @@ -2218,13 +2726,135 @@ int vfs_follow_link(struct nameidata *nd, const char *link) return __vfs_follow_link(nd, link); } + +#ifdef CONFIG_VSERVER_COWBL + +#include + +struct dentry *cow_break_link(const char *pathname) +{ + int ret, mode, pathlen; + struct nameidata old_nd, dir_nd; + struct dentry *old_dentry, *new_dentry; + struct dentry *res = ERR_PTR(-EMLINK); + struct vfsmount *old_mnt, *new_mnt; + struct file *old_file; + struct file *new_file; + char *to, *path, pad='\251'; + loff_t size; + + vxdprintk(VXD_CBIT(misc, 1), "cow_break_link(»%s«)", pathname); + path = kmalloc(PATH_MAX, GFP_KERNEL); + + ret = path_lookup(pathname, LOOKUP_FOLLOW, &old_nd); + vxdprintk(VXD_CBIT(misc, 2), "path_lookup(old): %d", ret); + old_dentry = old_nd.dentry; + old_mnt = old_nd.mnt; + mode = old_dentry->d_inode->i_mode; + + to = d_path(old_dentry, old_mnt, path, PATH_MAX-2); + pathlen = strlen(to); + vxdprintk(VXD_CBIT(misc, 2), "old path »%s«", to); + + to[pathlen+1] = 0; +retry: + to[pathlen] = pad--; + if (pad <= '\240') + goto out_rel_old; + + vxdprintk(VXD_CBIT(misc, 1), "temp copy »%s«", to); + ret = path_lookup(to, + LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE, &dir_nd); + + /* this puppy downs the inode sem */ + new_dentry = lookup_create(&dir_nd, 0); + vxdprintk(VXD_CBIT(misc, 2), + "lookup_create(new): %p", new_dentry); + if (!new_dentry) { + path_release(&dir_nd); + goto retry; + } + + ret = vfs_create(dir_nd.dentry->d_inode, new_dentry, mode, &dir_nd); + vxdprintk(VXD_CBIT(misc, 2), + "vfs_create(new): %d", ret); + if (ret == -EEXIST) { + mutex_unlock(&dir_nd.dentry->d_inode->i_mutex); + dput(new_dentry); + path_release(&dir_nd); + goto retry; + } + else if (ret < 0) { + res = ERR_PTR(ret); + goto out_rel_both; + } + + new_mnt = dir_nd.mnt; + + dget(old_dentry); + mntget(old_mnt); + /* this one cleans up the dentry in case of failure */ + old_file = dentry_open(old_dentry, old_mnt, O_RDONLY); + vxdprintk(VXD_CBIT(misc, 2), + "dentry_open(old): %p", old_file); + if (!old_file) + goto out_rel_both; + + dget(new_dentry); + mntget(new_mnt); + /* this one cleans up the dentry in case of failure */ + new_file = dentry_open(new_dentry, new_mnt, O_WRONLY); + vxdprintk(VXD_CBIT(misc, 2), + "dentry_open(new): %p", new_file); + if (!new_file) + goto out_fput_old; + + size = i_size_read(old_file->f_dentry->d_inode); + ret = vfs_sendfile(new_file, old_file, NULL, size, 0); + vxdprintk(VXD_CBIT(misc, 2), "vfs_sendfile: %d", ret); + + if (ret < 0) + goto out_fput_both; + + ret = vfs_rename(dir_nd.dentry->d_inode, new_dentry, + old_nd.dentry->d_parent->d_inode, old_dentry); + vxdprintk(VXD_CBIT(misc, 2), "vfs_rename: %d", ret); + if (!ret) { + res = new_dentry; + dget(new_dentry); + } + +out_fput_both: + vxdprintk(VXD_CBIT(misc, 3), + "fput(new_file=%p[#%d])", new_file, + atomic_read(&new_file->f_count)); + fput(new_file); + +out_fput_old: + vxdprintk(VXD_CBIT(misc, 3), + "fput(old_file=%p[#%d])", old_file, + atomic_read(&old_file->f_count)); + fput(old_file); + +out_rel_both: + mutex_unlock(&dir_nd.dentry->d_inode->i_mutex); + dput(new_dentry); + + path_release(&dir_nd); +out_rel_old: + path_release(&old_nd); + kfree(path); + return res; +} + +#endif + /* get the link contents into pagecache */ static char *page_getlink(struct dentry * dentry, struct page **ppage) { struct page * page; struct address_space *mapping = dentry->d_inode->i_mapping; - page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage, - NULL); + page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) goto sync_fail; wait_on_page_locked(page); @@ -2253,34 +2883,52 @@ int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) return res; } -int page_follow_link(struct dentry *dentry, struct nameidata *nd) +void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd) { struct page *page = NULL; - char *s = page_getlink(dentry, &page); - int res = __vfs_follow_link(nd, s); + nd_set_link(nd, page_getlink(dentry, &page)); + return page; +} + +void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) +{ + struct page *page = cookie; + if (page) { kunmap(page); page_cache_release(page); } - return res; } -int page_symlink(struct inode *inode, const char *symname, int len) +int __page_symlink(struct inode *inode, const char *symname, int len, + gfp_t gfp_mask) { struct address_space *mapping = inode->i_mapping; - struct page *page = grab_cache_page(mapping, 0); + struct page *page; int err = -ENOMEM; char *kaddr; +retry: + page = find_or_create_page(mapping, 0, gfp_mask); if (!page) goto fail; err = mapping->a_ops->prepare_write(NULL, page, 0, len-1); + if (err == AOP_TRUNCATED_PAGE) { + page_cache_release(page); + goto retry; + } if (err) goto fail_map; kaddr = kmap_atomic(page, KM_USER0); memcpy(kaddr, symname, len-1); kunmap_atomic(kaddr, KM_USER0); - mapping->a_ops->commit_write(NULL, page, 0, len-1); + err = mapping->a_ops->commit_write(NULL, page, 0, len-1); + if (err == AOP_TRUNCATED_PAGE) { + page_cache_release(page); + goto retry; + } + if (err) + goto fail_map; /* * Notice that we are _not_ going to block here - end of page is * unmapped, so this will only try to map the rest of page, see @@ -2290,7 +2938,8 @@ int page_symlink(struct inode *inode, const char *symname, int len) */ if (!PageUptodate(page)) { err = mapping->a_ops->readpage(NULL, page); - wait_on_page_locked(page); + if (err != AOP_TRUNCATED_PAGE) + wait_on_page_locked(page); } else { unlock_page(page); } @@ -2306,37 +2955,49 @@ fail: return err; } +int page_symlink(struct inode *inode, const char *symname, int len) +{ + return __page_symlink(inode, symname, len, + mapping_gfp_mask(inode->i_mapping)); +} + struct inode_operations page_symlink_inode_operations = { - .readlink = page_readlink, - .follow_link = page_follow_link, + .readlink = generic_readlink, + .follow_link = page_follow_link_light, + .put_link = page_put_link, }; EXPORT_SYMBOL(__user_walk); +EXPORT_SYMBOL(__user_walk_fd); EXPORT_SYMBOL(follow_down); EXPORT_SYMBOL(follow_up); EXPORT_SYMBOL(get_write_access); /* binfmt_aout */ EXPORT_SYMBOL(getname); EXPORT_SYMBOL(lock_rename); -EXPORT_SYMBOL(lookup_create); -EXPORT_SYMBOL(lookup_hash); EXPORT_SYMBOL(lookup_one_len); -EXPORT_SYMBOL(page_follow_link); +EXPORT_SYMBOL(page_follow_link_light); +EXPORT_SYMBOL(page_put_link); EXPORT_SYMBOL(page_readlink); +EXPORT_SYMBOL(__page_symlink); EXPORT_SYMBOL(page_symlink); EXPORT_SYMBOL(page_symlink_inode_operations); EXPORT_SYMBOL(path_lookup); EXPORT_SYMBOL(path_release); EXPORT_SYMBOL(path_walk); EXPORT_SYMBOL(permission); +EXPORT_SYMBOL(vfs_permission); +EXPORT_SYMBOL(file_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create); EXPORT_SYMBOL(vfs_follow_link); EXPORT_SYMBOL(vfs_link); EXPORT_SYMBOL(vfs_mkdir); EXPORT_SYMBOL(vfs_mknod); -EXPORT_SYMBOL(vfs_permission); +EXPORT_SYMBOL(generic_permission); EXPORT_SYMBOL(vfs_readlink); EXPORT_SYMBOL(vfs_rename); EXPORT_SYMBOL(vfs_rmdir); EXPORT_SYMBOL(vfs_symlink); EXPORT_SYMBOL(vfs_unlink); +EXPORT_SYMBOL(dentry_unhash); +EXPORT_SYMBOL(generic_readlink);