diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 701 |
1 files changed, 486 insertions, 215 deletions
@@ -463,25 +463,9 @@ err_root: return -ECHILD; } -/** - * release_open_intent - free up open intent resources - * @nd: pointer to nameidata - */ -void release_open_intent(struct nameidata *nd) +static inline int d_revalidate(struct dentry *dentry, unsigned int flags) { - struct file *file = nd->intent.open.file; - - if (file && !IS_ERR(file)) { - if (file->f_path.dentry == NULL) - put_filp(file); - else - fput(file); - } -} - -static inline int d_revalidate(struct dentry *dentry, struct nameidata *nd) -{ - return dentry->d_op->d_revalidate(dentry, nd); + return dentry->d_op->d_revalidate(dentry, flags); } /** @@ -527,7 +511,7 @@ static int complete_walk(struct nameidata *nd) return 0; /* Note: we do not d_invalidate() */ - status = d_revalidate(dentry, nd); + status = d_revalidate(dentry, nd->flags); if (status > 0) return 0; @@ -602,10 +586,25 @@ static inline void path_to_nameidata(const struct path *path, nd->path.dentry = path->dentry; } +/* + * Helper to directly jump to a known parsed path from ->follow_link, + * caller must have taken a reference to path beforehand. + */ +void nd_jump_link(struct nameidata *nd, struct path *path) +{ + path_put(&nd->path); + + nd->path = *path; + nd->inode = nd->path.dentry->d_inode; + nd->flags |= LOOKUP_JUMPED; + + BUG_ON(nd->inode->i_op->follow_link); +} + static inline void put_link(struct nameidata *nd, struct path *link, void *cookie) { struct inode *inode = link->dentry->d_inode; - if (!IS_ERR(cookie) && inode->i_op->put_link) + if (inode->i_op->put_link) inode->i_op->put_link(link->dentry, nd, cookie); path_put(link); } @@ -613,19 +612,19 @@ static inline void put_link(struct nameidata *nd, struct path *link, void *cooki static __always_inline int follow_link(struct path *link, struct nameidata *nd, void **p) { - int error; struct dentry *dentry = link->dentry; + int error; + char *s; BUG_ON(nd->flags & LOOKUP_RCU); if (link->mnt == nd->path.mnt) mntget(link->mnt); - if (unlikely(current->total_link_count >= 40)) { - *p = ERR_PTR(-ELOOP); /* no ->put_link(), please */ - path_put(&nd->path); - return -ELOOP; - } + error = -ELOOP; + if (unlikely(current->total_link_count >= 40)) + goto out_put_nd_path; + cond_resched(); current->total_link_count++; @@ -633,30 +632,28 @@ follow_link(struct path *link, struct nameidata *nd, void **p) nd_set_link(nd, NULL); error = security_inode_follow_link(link->dentry, nd); - if (error) { - *p = ERR_PTR(error); /* no ->put_link(), please */ - path_put(&nd->path); - return error; - } + if (error) + goto out_put_nd_path; nd->last_type = LAST_BIND; *p = dentry->d_inode->i_op->follow_link(dentry, nd); error = PTR_ERR(*p); - if (!IS_ERR(*p)) { - char *s = nd_get_link(nd); - error = 0; - if (s) - error = __vfs_follow_link(nd, s); - else if (nd->last_type == LAST_BIND) { - nd->flags |= LOOKUP_JUMPED; - nd->inode = nd->path.dentry->d_inode; - if (nd->inode->i_op->follow_link) { - /* stepped on a _really_ weird one */ - path_put(&nd->path); - error = -ELOOP; - } - } + if (IS_ERR(*p)) + goto out_put_nd_path; + + error = 0; + s = nd_get_link(nd); + if (s) { + error = __vfs_follow_link(nd, s); + if (unlikely(error)) + put_link(nd, link, *p); } + + return error; + +out_put_nd_path: + path_put(&nd->path); + path_put(link); return error; } @@ -675,6 +672,16 @@ static int follow_up_rcu(struct path *path) return 1; } +/* + * follow_up - Find the mountpoint of path's vfsmount + * + * Given a path, find the mountpoint of its source file system. + * Replace @path with the path of the mountpoint in the parent mount. + * Up is towards /. + * + * Return 1 if we went up a level and 0 if we were already at the + * root. + */ int follow_up(struct path *path) { struct mount *mnt = real_mount(path->mnt); @@ -1048,7 +1055,7 @@ static void follow_dotdot(struct nameidata *nd) * dir->d_inode->i_mutex must be held */ static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir, - struct nameidata *nd, bool *need_lookup) + unsigned int flags, bool *need_lookup) { struct dentry *dentry; int error; @@ -1059,7 +1066,7 @@ static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir, if (d_need_lookup(dentry)) { *need_lookup = true; } else if (dentry->d_flags & DCACHE_OP_REVALIDATE) { - error = d_revalidate(dentry, nd); + error = d_revalidate(dentry, flags); if (unlikely(error <= 0)) { if (error < 0) { dput(dentry); @@ -1089,7 +1096,7 @@ static struct dentry *lookup_dcache(struct qstr *name, struct dentry *dir, * dir->d_inode->i_mutex must be held */ static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry, - struct nameidata *nd) + unsigned int flags) { struct dentry *old; @@ -1099,7 +1106,7 @@ static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry, return ERR_PTR(-ENOENT); } - old = dir->i_op->lookup(dir, dentry, nd); + old = dir->i_op->lookup(dir, dentry, flags); if (unlikely(old)) { dput(dentry); dentry = old; @@ -1108,16 +1115,16 @@ static struct dentry *lookup_real(struct inode *dir, struct dentry *dentry, } static struct dentry *__lookup_hash(struct qstr *name, - struct dentry *base, struct nameidata *nd) + struct dentry *base, unsigned int flags) { bool need_lookup; struct dentry *dentry; - dentry = lookup_dcache(name, base, nd, &need_lookup); + dentry = lookup_dcache(name, base, flags, &need_lookup); if (!need_lookup) return dentry; - return lookup_real(base->d_inode, dentry, nd); + return lookup_real(base->d_inode, dentry, flags); } /* @@ -1167,7 +1174,7 @@ static int lookup_fast(struct nameidata *nd, struct qstr *name, if (unlikely(d_need_lookup(dentry))) goto unlazy; if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) { - status = d_revalidate(dentry, nd); + status = d_revalidate(dentry, nd->flags); if (unlikely(status <= 0)) { if (status != -ECHILD) need_reval = 0; @@ -1197,7 +1204,7 @@ unlazy: } if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE) && need_reval) - status = d_revalidate(dentry, nd); + status = d_revalidate(dentry, nd->flags); if (unlikely(status <= 0)) { if (status < 0) { dput(dentry); @@ -1236,7 +1243,7 @@ static int lookup_slow(struct nameidata *nd, struct qstr *name, BUG_ON(nd->inode != parent->d_inode); mutex_lock(&parent->d_inode->i_mutex); - dentry = __lookup_hash(name, parent, nd); + dentry = __lookup_hash(name, parent, nd->flags); mutex_unlock(&parent->d_inode->i_mutex); if (IS_ERR(dentry)) return PTR_ERR(dentry); @@ -1383,9 +1390,10 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd) void *cookie; res = follow_link(&link, nd, &cookie); - if (!res) - res = walk_component(nd, path, &nd->last, - nd->last_type, LOOKUP_FOLLOW); + if (res) + break; + res = walk_component(nd, path, &nd->last, + nd->last_type, LOOKUP_FOLLOW); put_link(nd, &link, cookie); } while (res > 0); @@ -1777,8 +1785,9 @@ static int path_lookupat(int dfd, const char *name, struct path link = path; nd->flags |= LOOKUP_PARENT; err = follow_link(&link, nd, &cookie); - if (!err) - err = lookup_last(nd, &path); + if (err) + break; + err = lookup_last(nd, &path); put_link(nd, &link, cookie); } } @@ -1821,9 +1830,27 @@ static int do_path_lookup(int dfd, const char *name, return retval; } -int kern_path_parent(const char *name, struct nameidata *nd) +/* does lookup, returns the object with parent locked */ +struct dentry *kern_path_locked(const char *name, struct path *path) { - return do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, nd); + struct nameidata nd; + struct dentry *d; + int err = do_path_lookup(AT_FDCWD, name, LOOKUP_PARENT, &nd); + if (err) + return ERR_PTR(err); + if (nd.last_type != LAST_NORM) { + path_put(&nd.path); + return ERR_PTR(-EINVAL); + } + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); + d = lookup_one_len(nd.last.name, nd.path.dentry, nd.last.len); + if (IS_ERR(d)) { + mutex_unlock(&nd.path.dentry->d_inode->i_mutex); + path_put(&nd.path); + return d; + } + *path = nd.path; + return d; } int kern_path(const char *name, unsigned int flags, struct path *path) @@ -1866,7 +1893,7 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, */ static struct dentry *lookup_hash(struct nameidata *nd) { - return __lookup_hash(&nd->last, nd->path.dentry, nd); + return __lookup_hash(&nd->last, nd->path.dentry, nd->flags); } /** @@ -1913,7 +1940,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) if (err) return ERR_PTR(err); - return __lookup_hash(&this, base, NULL); + return __lookup_hash(&this, base, 0); } int user_path_at_empty(int dfd, const char __user *name, unsigned flags, @@ -2086,10 +2113,9 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) } int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, - struct nameidata *nd) + bool want_excl) { int error = may_create(dir, dentry); - if (error) return error; @@ -2100,7 +2126,7 @@ int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, error = security_inode_create(dir, dentry, mode); if (error) return error; - error = dir->i_op->create(dir, dentry, mode, nd); + error = dir->i_op->create(dir, dentry, mode, want_excl); if (!error) fsnotify_create(dir, dentry); return error; @@ -2187,21 +2213,275 @@ static inline int open_to_namei_flags(int flag) return flag; } +static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode) +{ + int error = security_path_mknod(dir, dentry, mode, 0); + if (error) + return error; + + error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); + if (error) + return error; + + return security_inode_create(dir->dentry->d_inode, dentry, mode); +} + /* - * Handle the last step of open() + * Attempt to atomically look up, create and open a file from a negative + * dentry. + * + * Returns 0 if successful. The file will have been created and attached to + * @file by the filesystem calling finish_open(). + * + * Returns 1 if the file was looked up only or didn't need creating. The + * caller will need to perform the open themselves. @path will have been + * updated to point to the new dentry. This may be negative. + * + * Returns an error code otherwise. */ -static struct file *do_last(struct nameidata *nd, struct path *path, - const struct open_flags *op, const char *pathname) +static int atomic_open(struct nameidata *nd, struct dentry *dentry, + struct path *path, struct file *file, + const struct open_flags *op, + bool *want_write, bool need_lookup, + int *opened) +{ + struct inode *dir = nd->path.dentry->d_inode; + unsigned open_flag = open_to_namei_flags(op->open_flag); + umode_t mode; + int error; + int acc_mode; + int create_error = 0; + struct dentry *const DENTRY_NOT_SET = (void *) -1UL; + + BUG_ON(dentry->d_inode); + + /* Don't create child dentry for a dead directory. */ + if (unlikely(IS_DEADDIR(dir))) { + error = -ENOENT; + goto out; + } + + mode = op->mode & S_IALLUGO; + if ((open_flag & O_CREAT) && !IS_POSIXACL(dir)) + mode &= ~current_umask(); + + if (open_flag & O_EXCL) { + open_flag &= ~O_TRUNC; + *opened |= FILE_CREATED; + } + + /* + * Checking write permission is tricky, bacuse we don't know if we are + * going to actually need it: O_CREAT opens should work as long as the + * file exists. But checking existence breaks atomicity. The trick is + * to check access and if not granted clear O_CREAT from the flags. + * + * Another problem is returing the "right" error value (e.g. for an + * O_EXCL open we want to return EEXIST not EROFS). + */ + if ((open_flag & (O_CREAT | O_TRUNC)) || + (open_flag & O_ACCMODE) != O_RDONLY) { + error = mnt_want_write(nd->path.mnt); + if (!error) { + *want_write = true; + } else if (!(open_flag & O_CREAT)) { + /* + * No O_CREATE -> atomicity not a requirement -> fall + * back to lookup + open + */ + goto no_open; + } else if (open_flag & (O_EXCL | O_TRUNC)) { + /* Fall back and fail with the right error */ + create_error = error; + goto no_open; + } else { + /* No side effects, safe to clear O_CREAT */ + create_error = error; + open_flag &= ~O_CREAT; + } + } + + if (open_flag & O_CREAT) { + error = may_o_create(&nd->path, dentry, op->mode); + if (error) { + create_error = error; + if (open_flag & O_EXCL) + goto no_open; + open_flag &= ~O_CREAT; + } + } + + if (nd->flags & LOOKUP_DIRECTORY) + open_flag |= O_DIRECTORY; + + file->f_path.dentry = DENTRY_NOT_SET; + file->f_path.mnt = nd->path.mnt; + error = dir->i_op->atomic_open(dir, dentry, file, open_flag, mode, + opened); + if (error < 0) { + if (create_error && error == -ENOENT) + error = create_error; + goto out; + } + + acc_mode = op->acc_mode; + if (*opened & FILE_CREATED) { + fsnotify_create(dir, dentry); + acc_mode = MAY_OPEN; + } + + if (error) { /* returned 1, that is */ + if (WARN_ON(file->f_path.dentry == DENTRY_NOT_SET)) { + error = -EIO; + goto out; + } + if (file->f_path.dentry) { + dput(dentry); + dentry = file->f_path.dentry; + } + goto looked_up; + } + + /* + * We didn't have the inode before the open, so check open permission + * here. + */ + error = may_open(&file->f_path, acc_mode, open_flag); + if (error) + fput(file); + +out: + dput(dentry); + return error; + +no_open: + if (need_lookup) { + dentry = lookup_real(dir, dentry, nd->flags); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + if (create_error) { + int open_flag = op->open_flag; + + error = create_error; + if ((open_flag & O_EXCL)) { + if (!dentry->d_inode) + goto out; + } else if (!dentry->d_inode) { + goto out; + } else if ((open_flag & O_TRUNC) && + S_ISREG(dentry->d_inode->i_mode)) { + goto out; + } + /* will fail later, go on to get the right error */ + } + } +looked_up: + path->dentry = dentry; + path->mnt = nd->path.mnt; + return 1; +} + +/* + * Look up and maybe create and open the last component. + * + * Must be called with i_mutex held on parent. + * + * Returns 0 if the file was successfully atomically created (if necessary) and + * opened. In this case the file will be returned attached to @file. + * + * Returns 1 if the file was not completely opened at this time, though lookups + * and creations will have been performed and the dentry returned in @path will + * be positive upon return if O_CREAT was specified. If O_CREAT wasn't + * specified then a negative dentry may be returned. + * + * An error code is returned otherwise. + * + * FILE_CREATE will be set in @*opened if the dentry was created and will be + * cleared otherwise prior to returning. + */ +static int lookup_open(struct nameidata *nd, struct path *path, + struct file *file, + const struct open_flags *op, + bool *want_write, int *opened) { struct dentry *dir = nd->path.dentry; + struct inode *dir_inode = dir->d_inode; struct dentry *dentry; + int error; + bool need_lookup; + + *opened &= ~FILE_CREATED; + dentry = lookup_dcache(&nd->last, dir, nd->flags, &need_lookup); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + /* Cached positive dentry: will open in f_op->open */ + if (!need_lookup && dentry->d_inode) + goto out_no_open; + + if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) { + return atomic_open(nd, dentry, path, file, op, want_write, + need_lookup, opened); + } + + if (need_lookup) { + BUG_ON(dentry->d_inode); + + dentry = lookup_real(dir_inode, dentry, nd->flags); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + } + + /* Negative dentry, just create the file */ + if (!dentry->d_inode && (op->open_flag & O_CREAT)) { + umode_t mode = op->mode; + if (!IS_POSIXACL(dir->d_inode)) + mode &= ~current_umask(); + /* + * This write is needed to ensure that a + * rw->ro transition does not occur between + * the time when the file is created and when + * a permanent write count is taken through + * the 'struct file' in finish_open(). + */ + error = mnt_want_write(nd->path.mnt); + if (error) + goto out_dput; + *want_write = true; + *opened |= FILE_CREATED; + error = security_path_mknod(&nd->path, dentry, mode, 0); + if (error) + goto out_dput; + error = vfs_create(dir->d_inode, dentry, mode, + nd->flags & LOOKUP_EXCL); + if (error) + goto out_dput; + } +out_no_open: + path->dentry = dentry; + path->mnt = nd->path.mnt; + return 1; + +out_dput: + dput(dentry); + return error; +} + +/* + * Handle the last step of open() + */ +static int do_last(struct nameidata *nd, struct path *path, + struct file *file, const struct open_flags *op, + int *opened, const char *pathname) +{ + struct dentry *dir = nd->path.dentry; int open_flag = op->open_flag; - int will_truncate = open_flag & O_TRUNC; - int want_write = 0; + bool will_truncate = (open_flag & O_TRUNC) != 0; + bool want_write = false; int acc_mode = op->acc_mode; - struct file *filp; struct inode *inode; - int symlink_ok = 0; + bool symlink_ok = false; struct path save_parent = { .dentry = NULL, .mnt = NULL }; bool retried = false; int error; @@ -2214,112 +2494,99 @@ static struct file *do_last(struct nameidata *nd, struct path *path, case LAST_DOT: error = handle_dots(nd, nd->last_type); if (error) - return ERR_PTR(error); + return error; /* fallthrough */ case LAST_ROOT: error = complete_walk(nd); if (error) - return ERR_PTR(error); + return error; audit_inode(pathname, nd->path.dentry); if (open_flag & O_CREAT) { error = -EISDIR; - goto exit; + goto out; } - goto ok; + goto finish_open; case LAST_BIND: error = complete_walk(nd); if (error) - return ERR_PTR(error); + return error; audit_inode(pathname, dir); - goto ok; + goto finish_open; } if (!(open_flag & O_CREAT)) { if (nd->last.name[nd->last.len]) nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY; if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW)) - symlink_ok = 1; + symlink_ok = true; /* we _can_ be in RCU mode here */ error = lookup_fast(nd, &nd->last, path, &inode); - if (unlikely(error)) { - if (error < 0) - goto exit; + if (likely(!error)) + goto finish_lookup; - error = lookup_slow(nd, &nd->last, path); - if (error < 0) - goto exit; + if (error < 0) + goto out; - inode = path->dentry->d_inode; - } - goto finish_lookup; - } - - /* create side of things */ - /* - * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED has been - * cleared when we got to the last component we are about to look up - */ - error = complete_walk(nd); - if (error) - return ERR_PTR(error); + BUG_ON(nd->inode != dir->d_inode); + } else { + /* create side of things */ + /* + * This will *only* deal with leaving RCU mode - LOOKUP_JUMPED + * has been cleared when we got to the last component we are + * about to look up + */ + error = complete_walk(nd); + if (error) + return error; - audit_inode(pathname, dir); - error = -EISDIR; - /* trailing slashes? */ - if (nd->last.name[nd->last.len]) - goto exit; + audit_inode(pathname, dir); + error = -EISDIR; + /* trailing slashes? */ + if (nd->last.name[nd->last.len]) + goto out; + } retry_lookup: mutex_lock(&dir->d_inode->i_mutex); + error = lookup_open(nd, path, file, op, &want_write, opened); + mutex_unlock(&dir->d_inode->i_mutex); - dentry = lookup_hash(nd); - error = PTR_ERR(dentry); - if (IS_ERR(dentry)) { - mutex_unlock(&dir->d_inode->i_mutex); - goto exit; - } + if (error <= 0) { + if (error) + goto out; - path->dentry = dentry; - path->mnt = nd->path.mnt; + if ((*opened & FILE_CREATED) || + !S_ISREG(file->f_path.dentry->d_inode->i_mode)) + will_truncate = false; - /* Negative dentry, just create the file */ - if (!dentry->d_inode) { - umode_t mode = op->mode; - if (!IS_POSIXACL(dir->d_inode)) - mode &= ~current_umask(); - /* - * This write is needed to ensure that a - * rw->ro transition does not occur between - * the time when the file is created and when - * a permanent write count is taken through - * the 'struct file' in nameidata_to_filp(). - */ - error = mnt_want_write(nd->path.mnt); - if (error) - goto exit_mutex_unlock; - want_write = 1; + audit_inode(pathname, file->f_path.dentry); + goto opened; + } + + if (*opened & FILE_CREATED) { /* Don't check for write permission, don't truncate */ open_flag &= ~O_TRUNC; - will_truncate = 0; + will_truncate = false; acc_mode = MAY_OPEN; - error = security_path_mknod(&nd->path, dentry, mode, 0); - if (error) - goto exit_mutex_unlock; - error = vfs_create(dir->d_inode, dentry, mode, nd); - if (error) - goto exit_mutex_unlock; - mutex_unlock(&dir->d_inode->i_mutex); - dput(nd->path.dentry); - nd->path.dentry = dentry; - goto common; + path_to_nameidata(path, nd); + goto finish_open_created; } /* * It already exists. */ - mutex_unlock(&dir->d_inode->i_mutex); audit_inode(pathname, path->dentry); + /* + * If atomic_open() acquired write access it is dropped now due to + * possible mount and symlink following (this might be optimized away if + * necessary...) + */ + if (want_write) { + mnt_drop_write(nd->path.mnt); + want_write = false; + } + error = -EEXIST; if (open_flag & O_EXCL) goto exit_dput; @@ -2338,18 +2605,18 @@ finish_lookup: error = -ENOENT; if (!inode) { path_to_nameidata(path, nd); - goto exit; + goto out; } if (should_follow_link(inode, !symlink_ok)) { if (nd->flags & LOOKUP_RCU) { if (unlikely(unlazy_walk(nd, path->dentry))) { error = -ECHILD; - goto exit; + goto out; } } BUG_ON(inode != path->dentry->d_inode); - return NULL; + return 1; } if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) { @@ -2365,119 +2632,122 @@ finish_lookup: error = complete_walk(nd); if (error) { path_put(&save_parent); - return ERR_PTR(error); + return error; } error = -EISDIR; if ((open_flag & O_CREAT) && S_ISDIR(nd->inode->i_mode)) - goto exit; + goto out; error = -ENOTDIR; if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup) - goto exit; + goto out; audit_inode(pathname, nd->path.dentry); -ok: +finish_open: if (!S_ISREG(nd->inode->i_mode)) - will_truncate = 0; + will_truncate = false; if (will_truncate) { error = mnt_want_write(nd->path.mnt); if (error) - goto exit; - want_write = 1; + goto out; + want_write = true; } -common: +finish_open_created: error = may_open(&nd->path, acc_mode, open_flag); if (error) - goto exit; - filp = nameidata_to_filp(nd); - if (filp == ERR_PTR(-EOPENSTALE) && save_parent.dentry && !retried) { - BUG_ON(save_parent.dentry != dir); - path_put(&nd->path); - nd->path = save_parent; - nd->inode = dir->d_inode; - save_parent.mnt = NULL; - save_parent.dentry = NULL; - if (want_write) { - mnt_drop_write(nd->path.mnt); - want_write = 0; - } - retried = true; - goto retry_lookup; - } - if (!IS_ERR(filp)) { - error = ima_file_check(filp, op->acc_mode); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } + goto out; + file->f_path.mnt = nd->path.mnt; + error = finish_open(file, nd->path.dentry, NULL, opened); + if (error) { + if (error == -EOPENSTALE) + goto stale_open; + goto out; } - if (!IS_ERR(filp)) { - if (will_truncate) { - error = handle_truncate(filp); - if (error) { - fput(filp); - filp = ERR_PTR(error); - } - } +opened: + error = open_check_o_direct(file); + if (error) + goto exit_fput; + error = ima_file_check(file, op->acc_mode); + if (error) + goto exit_fput; + + if (will_truncate) { + error = handle_truncate(file); + if (error) + goto exit_fput; } out: if (want_write) mnt_drop_write(nd->path.mnt); path_put(&save_parent); terminate_walk(nd); - return filp; + return error; -exit_mutex_unlock: - mutex_unlock(&dir->d_inode->i_mutex); exit_dput: path_put_conditional(path, nd); -exit: - filp = ERR_PTR(error); goto out; +exit_fput: + fput(file); + goto out; + +stale_open: + /* If no saved parent or already retried then can't retry */ + if (!save_parent.dentry || retried) + goto out; + + BUG_ON(save_parent.dentry != dir); + path_put(&nd->path); + nd->path = save_parent; + nd->inode = dir->d_inode; + save_parent.mnt = NULL; + save_parent.dentry = NULL; + if (want_write) { + mnt_drop_write(nd->path.mnt); + want_write = false; + } + retried = true; + goto retry_lookup; } static struct file *path_openat(int dfd, const char *pathname, struct nameidata *nd, const struct open_flags *op, int flags) { struct file *base = NULL; - struct file *filp; + struct file *file; struct path path; + int opened = 0; int error; - filp = get_empty_filp(); - if (!filp) + file = get_empty_filp(); + if (!file) return ERR_PTR(-ENFILE); - filp->f_flags = op->open_flag; - nd->intent.open.file = filp; - nd->intent.open.flags = open_to_namei_flags(op->open_flag); - nd->intent.open.create_mode = op->mode; + file->f_flags = op->open_flag; error = path_init(dfd, pathname, flags | LOOKUP_PARENT, nd, &base); if (unlikely(error)) - goto out_filp; + goto out; current->total_link_count = 0; error = link_path_walk(pathname, nd); if (unlikely(error)) - goto out_filp; + goto out; - filp = do_last(nd, &path, op, pathname); - while (unlikely(!filp)) { /* trailing symlink */ + error = do_last(nd, &path, file, op, &opened, pathname); + while (unlikely(error > 0)) { /* trailing symlink */ struct path link = path; void *cookie; if (!(nd->flags & LOOKUP_FOLLOW)) { path_put_conditional(&path, nd); path_put(&nd->path); - filp = ERR_PTR(-ELOOP); + error = -ELOOP; break; } nd->flags |= LOOKUP_PARENT; nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL); error = follow_link(&link, nd, &cookie); if (unlikely(error)) - filp = ERR_PTR(error); - else - filp = do_last(nd, &path, op, pathname); + break; + error = do_last(nd, &path, file, op, &opened, pathname); put_link(nd, &link, cookie); } out: @@ -2485,18 +2755,20 @@ out: path_put(&nd->root); if (base) fput(base); - release_open_intent(nd); - if (filp == ERR_PTR(-EOPENSTALE)) { - if (flags & LOOKUP_RCU) - filp = ERR_PTR(-ECHILD); - else - filp = ERR_PTR(-ESTALE); + if (!(opened & FILE_OPENED)) { + BUG_ON(!error); + put_filp(file); } - return filp; - -out_filp: - filp = ERR_PTR(error); - goto out; + if (unlikely(error)) { + if (error == -EOPENSTALE) { + if (flags & LOOKUP_RCU) + error = -ECHILD; + else + error = -ESTALE; + } + file = ERR_PTR(error); + } + return file; } struct file *do_filp_open(int dfd, const char *pathname, @@ -2551,7 +2823,6 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path goto out; nd.flags &= ~LOOKUP_PARENT; nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL; - nd.intent.open.flags = O_EXCL; /* * Do the final lookup. @@ -2670,7 +2941,7 @@ SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, umode_t, mode, goto out_drop_write; switch (mode & S_IFMT) { case 0: case S_IFREG: - error = vfs_create(path.dentry->d_inode,dentry,mode,NULL); + error = vfs_create(path.dentry->d_inode,dentry,mode,true); break; case S_IFCHR: case S_IFBLK: error = vfs_mknod(path.dentry->d_inode,dentry,mode, |