diff options
Diffstat (limited to 'fs/autofs')
| -rw-r--r-- | fs/autofs/Kconfig | 13 | ||||
| -rw-r--r-- | fs/autofs/Makefile | 1 | ||||
| -rw-r--r-- | fs/autofs/autofs_i.h | 51 | ||||
| -rw-r--r-- | fs/autofs/dev-ioctl.c | 159 | ||||
| -rw-r--r-- | fs/autofs/expire.c | 130 | ||||
| -rw-r--r-- | fs/autofs/init.c | 15 | ||||
| -rw-r--r-- | fs/autofs/inode.c | 472 | ||||
| -rw-r--r-- | fs/autofs/root.c | 232 | ||||
| -rw-r--r-- | fs/autofs/symlink.c | 5 | ||||
| -rw-r--r-- | fs/autofs/waitq.c | 86 |
10 files changed, 603 insertions, 561 deletions
diff --git a/fs/autofs/Kconfig b/fs/autofs/Kconfig index eaebcd430cc3..54c12d9484cb 100644 --- a/fs/autofs/Kconfig +++ b/fs/autofs/Kconfig @@ -1,17 +1,6 @@ -config AUTOFS4_FS - tristate "Old Kconfig name for Kernel automounter support" - select AUTOFS_FS - help - This name exists for people to just automatically pick up the - new name of the autofs Kconfig option. All it does is select - the new option name. - - It will go away in a release or two as people have - transitioned to just plain AUTOFS_FS. - +# SPDX-License-Identifier: GPL-2.0-only config AUTOFS_FS tristate "Kernel automounter support (supports v3, v4 and v5)" - default n help The automounter is a tool to automatically mount remote file systems on demand. This implementation is partially kernel-based to reduce diff --git a/fs/autofs/Makefile b/fs/autofs/Makefile index 1f85d35ec8b7..495ac542e172 100644 --- a/fs/autofs/Makefile +++ b/fs/autofs/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0-only # # Makefile for the linux autofs-filesystem routines. # diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h index 3e59f0ed777b..4fd555528c5d 100644 --- a/fs/autofs/autofs_i.h +++ b/fs/autofs/autofs_i.h @@ -1,10 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright 1997-1998 Transmeta Corporation - All Rights Reserved * Copyright 2005-2006 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ /* Internal header file for autofs */ @@ -19,6 +16,7 @@ #include <linux/wait.h> #include <linux/sched.h> #include <linux/sched/signal.h> +#include <uapi/linux/mount.h> #include <linux/mount.h> #include <linux/namei.h> #include <linux/uaccess.h> @@ -28,6 +26,11 @@ #include <linux/completion.h> #include <linux/file.h> #include <linux/magic.h> +#include <linux/fs_context.h> +#include <linux/fs_parser.h> +#include "../mount.h" +#include <linux/ns_common.h> + /* This is the range of ioctl() numbers we claim as ours */ #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY @@ -54,23 +57,22 @@ extern struct file_system_type autofs_fs_type; */ struct autofs_info { struct dentry *dentry; - struct inode *inode; - int flags; struct completion expire_complete; struct list_head active; - int active_count; struct list_head expiring; struct autofs_sb_info *sbi; + unsigned long exp_timeout; unsigned long last_used; - atomic_t count; + int count; kuid_t uid; kgid_t gid; + struct rcu_head rcu; }; #define AUTOFS_INF_EXPIRING (1<<0) /* dentry in the process of expiring */ @@ -84,12 +86,16 @@ struct autofs_info { */ #define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */ +#define AUTOFS_INF_EXPIRE_SET (1<<3) /* per-dentry expire timeout set for + this mount point. + */ struct autofs_wait_queue { wait_queue_head_t queue; struct autofs_wait_queue *next; autofs_wqt_t wait_queue_token; /* We use the following to see what we are waiting for */ struct qstr name; + u32 offset; u32 dev; u64 ino; kuid_t uid; @@ -105,12 +111,14 @@ struct autofs_wait_queue { #define AUTOFS_SBI_CATATONIC 0x0001 #define AUTOFS_SBI_STRICTEXPIRE 0x0002 +#define AUTOFS_SBI_IGNORE 0x0004 struct autofs_sb_info { u32 magic; int pipefd; struct file *pipe; struct pid *oz_pgrp; + u64 mnt_ns_id; int version; int sub_version; int min_proto; @@ -149,6 +157,11 @@ static inline int autofs_oz_mode(struct autofs_sb_info *sbi) task_pgrp(current) == sbi->oz_pgrp); } +static inline bool autofs_empty(struct autofs_info *ino) +{ + return ino->count < 2; +} + struct inode *autofs_get_inode(struct super_block *, umode_t); void autofs_free_ino(struct autofs_info *); @@ -203,18 +216,36 @@ static inline void managed_dentry_clear_managed(struct dentry *dentry) /* Initializing function */ -int autofs_fill_super(struct super_block *, void *, int); +extern const struct fs_parameter_spec autofs_param_specs[]; +int autofs_init_fs_context(struct fs_context *fc); struct autofs_info *autofs_new_ino(struct autofs_sb_info *); void autofs_clean_ino(struct autofs_info *); -static inline int autofs_prepare_pipe(struct file *pipe) +static inline int autofs_check_pipe(struct file *pipe) { + if (pipe->f_mode & FMODE_PATH) + return -EINVAL; if (!(pipe->f_mode & FMODE_CAN_WRITE)) return -EINVAL; if (!S_ISFIFO(file_inode(pipe)->i_mode)) return -EINVAL; + return 0; +} + +static inline void autofs_set_packet_pipe_flags(struct file *pipe) +{ /* We want a packet pipe */ pipe->f_flags |= O_DIRECT; + /* We don't expect -EAGAIN */ + pipe->f_flags &= ~O_NONBLOCK; +} + +static inline int autofs_prepare_pipe(struct file *pipe) +{ + int ret = autofs_check_pipe(pipe); + if (ret < 0) + return ret; + autofs_set_packet_pipe_flags(pipe); return 0; } diff --git a/fs/autofs/dev-ioctl.c b/fs/autofs/dev-ioctl.c index e9fe74d1541b..6743b3b64217 100644 --- a/fs/autofs/dev-ioctl.c +++ b/fs/autofs/dev-ioctl.c @@ -1,16 +1,15 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 2008 Red Hat, Inc. All rights reserved. * Copyright 2008 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ +#include <linux/module.h> #include <linux/miscdevice.h> #include <linux/compat.h> -#include <linux/syscalls.h> +#include <linux/fdtable.h> #include <linux/magic.h> +#include <linux/nospec.h> #include "autofs_i.h" @@ -23,7 +22,7 @@ * another mount. This situation arises when starting automount(8) * or other user space daemon which uses direct mounts or offset * mounts (used for autofs lazy mount/umount of nested mount trees), - * which have been left busy at at service shutdown. + * which have been left busy at service shutdown. */ typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *, @@ -111,6 +110,7 @@ static inline void free_dev_ioctl(struct autofs_dev_ioctl *param) */ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) { + unsigned int inr = _IOC_NR(cmd); int err; err = check_dev_ioctl_version(cmd, param); @@ -129,15 +129,19 @@ static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param) goto out; } + /* Setting the per-dentry expire timeout requires a trailing + * path component, ie. no '/', so invert the logic of the + * check_name() return for AUTOFS_DEV_IOCTL_TIMEOUT_CMD. + */ err = check_name(param->path); + if (inr == AUTOFS_DEV_IOCTL_TIMEOUT_CMD) + err = err ? 0 : -EINVAL; if (err) { pr_warn("invalid path supplied for cmd(0x%08x)\n", cmd); goto out; } } else { - unsigned int inr = _IOC_NR(cmd); - if (inr == AUTOFS_DEV_IOCTL_OPENMOUNT_CMD || inr == AUTOFS_DEV_IOCTL_REQUESTER_CMD || inr == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) { @@ -189,7 +193,7 @@ static int find_autofs_mount(const char *pathname, struct path path; int err; - err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0); + err = kern_path(pathname, LOOKUP_MOUNTPOINT, &path); if (err) return err; err = -ENOENT; @@ -227,32 +231,14 @@ static int test_by_type(const struct path *path, void *p) */ static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) { - int err, fd; - - fd = get_unused_fd_flags(O_CLOEXEC); - if (likely(fd >= 0)) { - struct file *filp; - struct path path; - - err = find_autofs_mount(name, &path, test_by_dev, &devid); - if (err) - goto out; - - filp = dentry_open(&path, O_RDONLY, current_cred()); - path_put(&path); - if (IS_ERR(filp)) { - err = PTR_ERR(filp); - goto out; - } - - fd_install(fd, filp); - } + struct path path __free(path_put) = {}; + int err; - return fd; + err = find_autofs_mount(name, &path, test_by_dev, &devid); + if (err) + return err; -out: - put_unused_fd(fd); - return err; + return FD_ADD(O_CLOEXEC, dentry_open(&path, O_RDONLY, current_cred())); } /* Open a file descriptor on an autofs mount point */ @@ -291,7 +277,7 @@ static int autofs_dev_ioctl_closemount(struct file *fp, struct autofs_sb_info *sbi, struct autofs_dev_ioctl *param) { - return ksys_close(param->ioctlfd); + return close_fd(param->ioctlfd); } /* @@ -377,6 +363,7 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp, swap(sbi->oz_pgrp, new_pid); sbi->pipefd = pipefd; sbi->pipe = pipe; + sbi->mnt_ns_id = to_ns_common(current->nsproxy->mnt_ns)->ns_id; sbi->flags &= ~AUTOFS_SBI_CATATONIC; } out: @@ -397,16 +384,97 @@ static int autofs_dev_ioctl_catatonic(struct file *fp, return 0; } -/* Set the autofs mount timeout */ +/* + * Set the autofs mount expire timeout. + * + * There are two places an expire timeout can be set, in the autofs + * super block info. (this is all that's needed for direct and offset + * mounts because there's a distinct mount corresponding to each of + * these) and per-dentry within within the dentry info. If a per-dentry + * timeout is set it will override the expire timeout set in the parent + * autofs super block info. + * + * If setting the autofs super block expire timeout the autofs_dev_ioctl + * size field will be equal to the autofs_dev_ioctl structure size. If + * setting the per-dentry expire timeout the mount point name is passed + * in the autofs_dev_ioctl path field and the size field updated to + * reflect this. + * + * Setting the autofs mount expire timeout sets the timeout in the super + * block info. struct. Setting the per-dentry timeout does a little more. + * If the timeout is equal to -1 the per-dentry timeout (and flag) is + * cleared which reverts to using the super block timeout, otherwise if + * timeout is 0 the timeout is set to this value and the flag is left + * set which disables expiration for the mount point, lastly the flag + * and the timeout are set enabling the dentry to use this timeout. + */ static int autofs_dev_ioctl_timeout(struct file *fp, struct autofs_sb_info *sbi, struct autofs_dev_ioctl *param) { - unsigned long timeout; + unsigned long timeout = param->timeout.timeout; + + /* If setting the expire timeout for an individual indirect + * mount point dentry the mount trailing component path is + * placed in param->path and param->size adjusted to account + * for it otherwise param->size it is set to the structure + * size. + */ + if (param->size == AUTOFS_DEV_IOCTL_SIZE) { + param->timeout.timeout = sbi->exp_timeout / HZ; + sbi->exp_timeout = timeout * HZ; + } else { + struct dentry *base = fp->f_path.dentry; + int path_len = param->size - AUTOFS_DEV_IOCTL_SIZE - 1; + struct dentry *dentry; + struct autofs_info *ino; + + if (!autofs_type_indirect(sbi->type)) + return -EINVAL; + + dentry = try_lookup_noperm(&QSTR_LEN(param->path, path_len), + base); + if (IS_ERR_OR_NULL(dentry)) + return dentry ? PTR_ERR(dentry) : -ENOENT; + ino = autofs_dentry_ino(dentry); + if (!ino) { + dput(dentry); + return -ENOENT; + } + + if (ino->exp_timeout && ino->flags & AUTOFS_INF_EXPIRE_SET) + param->timeout.timeout = ino->exp_timeout / HZ; + else + param->timeout.timeout = sbi->exp_timeout / HZ; + + if (timeout == -1) { + /* Revert to using the super block timeout */ + ino->flags &= ~AUTOFS_INF_EXPIRE_SET; + ino->exp_timeout = 0; + } else { + /* Set the dentry expire flag and timeout. + * + * If timeout is 0 it will prevent the expire + * of this particular automount. + */ + ino->flags |= AUTOFS_INF_EXPIRE_SET; + ino->exp_timeout = timeout * HZ; + } + + /* An expire timeout greater than the superblock timeout + * could be a problem at shutdown but the super block + * timeout itself can change so all we can really do is + * warn the user. + */ + if (ino->flags & AUTOFS_INF_EXPIRE_SET && + ino->exp_timeout > sbi->exp_timeout) + pr_warn("per-mount expire timeout is greater than " + "the parent autofs mount timeout which could " + "prevent shutdown\n"); + + dput(dentry); + } - timeout = param->timeout.timeout; - param->timeout.timeout = sbi->exp_timeout / HZ; - sbi->exp_timeout = timeout * HZ; return 0; } @@ -499,7 +567,7 @@ static int autofs_dev_ioctl_askumount(struct file *fp, * located path is the root of a mount we return 1 along with * the super magic of the mount or 0 otherwise. * - * In both cases the the device number (as returned by + * In both cases the device number (as returned by * new_encode_dev()) is also returned. */ static int autofs_dev_ioctl_ismountpoint(struct file *fp, @@ -522,8 +590,8 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp, if (!fp || param->ioctlfd == -1) { if (autofs_type_any(type)) - err = kern_path_mountpoint(AT_FDCWD, - name, &path, LOOKUP_FOLLOW); + err = kern_path(name, LOOKUP_FOLLOW | LOOKUP_MOUNTPOINT, + &path); else err = find_autofs_mount(name, &path, test_by_type, &type); @@ -566,7 +634,7 @@ out: static ioctl_fn lookup_dev_ioctl(unsigned int cmd) { - static ioctl_fn _ioctls[] = { + static const ioctl_fn _ioctls[] = { autofs_dev_ioctl_version, autofs_dev_ioctl_protover, autofs_dev_ioctl_protosubver, @@ -584,7 +652,10 @@ static ioctl_fn lookup_dev_ioctl(unsigned int cmd) }; unsigned int idx = cmd_idx(cmd); - return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx]; + if (idx >= ARRAY_SIZE(_ioctls)) + return NULL; + idx = array_index_nospec(idx, ARRAY_SIZE(_ioctls)); + return _ioctls[idx]; } /* ioctl dispatcher */ diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c index d441244b79df..5c2d459e1e48 100644 --- a/fs/autofs/expire.c +++ b/fs/autofs/expire.c @@ -1,11 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> * Copyright 2001-2006 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include "autofs_i.h" @@ -73,6 +70,24 @@ done: return status; } +/* p->d_lock held */ +static struct dentry *positive_after(struct dentry *p, struct dentry *child) +{ + child = child ? d_next_sibling(child) : d_first_child(p); + + hlist_for_each_entry_from(child, d_sib) { + spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED); + if (simple_positive(child)) { + dget_dlock(child); + spin_unlock(&child->d_lock); + return child; + } + spin_unlock(&child->d_lock); + } + + return NULL; +} + /* * Calculate and dget next entry in the subdirs list under root. */ @@ -80,43 +95,14 @@ static struct dentry *get_next_positive_subdir(struct dentry *prev, struct dentry *root) { struct autofs_sb_info *sbi = autofs_sbi(root->d_sb); - struct list_head *next; struct dentry *q; spin_lock(&sbi->lookup_lock); spin_lock(&root->d_lock); - - if (prev) - next = prev->d_child.next; - else { - prev = dget_dlock(root); - next = prev->d_subdirs.next; - } - -cont: - if (next == &root->d_subdirs) { - spin_unlock(&root->d_lock); - spin_unlock(&sbi->lookup_lock); - dput(prev); - return NULL; - } - - q = list_entry(next, struct dentry, d_child); - - spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED); - /* Already gone or negative dentry (under construction) - try next */ - if (!d_count(q) || !simple_positive(q)) { - spin_unlock(&q->d_lock); - next = q->d_child.next; - goto cont; - } - dget_dlock(q); - spin_unlock(&q->d_lock); + q = positive_after(root, prev); spin_unlock(&root->d_lock); spin_unlock(&sbi->lookup_lock); - dput(prev); - return q; } @@ -127,59 +113,28 @@ static struct dentry *get_next_positive_dentry(struct dentry *prev, struct dentry *root) { struct autofs_sb_info *sbi = autofs_sbi(root->d_sb); - struct list_head *next; - struct dentry *p, *ret; + struct dentry *p = prev, *ret = NULL, *d = NULL; if (prev == NULL) return dget(root); spin_lock(&sbi->lookup_lock); -relock: - p = prev; spin_lock(&p->d_lock); -again: - next = p->d_subdirs.next; - if (next == &p->d_subdirs) { - while (1) { - struct dentry *parent; - - if (p == root) { - spin_unlock(&p->d_lock); - spin_unlock(&sbi->lookup_lock); - dput(prev); - return NULL; - } - - parent = p->d_parent; - if (!spin_trylock(&parent->d_lock)) { - spin_unlock(&p->d_lock); - cpu_relax(); - goto relock; - } - spin_unlock(&p->d_lock); - next = p->d_child.next; - p = parent; - if (next != &parent->d_subdirs) - break; - } - } - ret = list_entry(next, struct dentry, d_child); + while (1) { + struct dentry *parent; - spin_lock_nested(&ret->d_lock, DENTRY_D_LOCK_NESTED); - /* Negative dentry - try next */ - if (!simple_positive(ret)) { + ret = positive_after(p, d); + if (ret || p == root) + break; + parent = p->d_parent; spin_unlock(&p->d_lock); - lock_set_subclass(&ret->d_lock.dep_map, 0, _RET_IP_); - p = ret; - goto again; + spin_lock(&parent->d_lock); + d = p; + p = parent; } - dget_dlock(ret); - spin_unlock(&ret->d_lock); spin_unlock(&p->d_lock); spin_unlock(&sbi->lookup_lock); - dput(prev); - return ret; } @@ -253,7 +208,7 @@ static int autofs_tree_busy(struct vfsmount *mnt, } } else { struct autofs_info *ino = autofs_dentry_ino(p); - unsigned int ino_count = atomic_read(&ino->count); + unsigned int ino_count = READ_ONCE(ino->count); /* allow for dget above and top is already dgot */ if (p == top) @@ -397,7 +352,7 @@ static struct dentry *should_expire(struct dentry *dentry, return NULL; } - if (d_really_is_positive(dentry) && d_is_symlink(dentry)) { + if (d_is_symlink(dentry)) { pr_debug("checking symlink %p %pd\n", dentry, dentry); /* Forced expire, user space handles busy mounts */ @@ -413,7 +368,7 @@ static struct dentry *should_expire(struct dentry *dentry, return NULL; } - if (simple_empty(dentry)) + if (autofs_empty(ino)) return NULL; /* Case 2: tree mount, expire iff entire tree is not busy */ @@ -421,7 +376,7 @@ static struct dentry *should_expire(struct dentry *dentry, /* Not a forced expire? */ if (!(how & AUTOFS_EXP_FORCED)) { /* ref-walk currently on this dentry? */ - ino_count = atomic_read(&ino->count) + 1; + ino_count = READ_ONCE(ino->count) + 1; if (d_count(dentry) > ino_count) return NULL; } @@ -438,7 +393,7 @@ static struct dentry *should_expire(struct dentry *dentry, /* Not a forced expire? */ if (!(how & AUTOFS_EXP_FORCED)) { /* ref-walk currently on this dentry? */ - ino_count = atomic_read(&ino->count) + 1; + ino_count = READ_ONCE(ino->count) + 1; if (d_count(dentry) > ino_count) return NULL; } @@ -474,8 +429,6 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb, if (!root) return NULL; - timeout = sbi->exp_timeout; - dentry = NULL; while ((dentry = get_next_positive_subdir(dentry, root))) { spin_lock(&sbi->fs_lock); @@ -486,6 +439,11 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb, } spin_unlock(&sbi->fs_lock); + if (ino->flags & AUTOFS_INF_EXPIRE_SET) + timeout = ino->exp_timeout; + else + timeout = sbi->exp_timeout; + expired = should_expire(dentry, mnt, timeout, how); if (!expired) continue; @@ -501,9 +459,10 @@ static struct dentry *autofs_expire_indirect(struct super_block *sb, */ how &= ~AUTOFS_EXP_LEAVES; found = should_expire(expired, mnt, timeout, how); - if (!found || found != expired) - /* Something has changed, continue */ + if (found != expired) { // something has changed, continue + dput(found); goto next; + } if (expired != dentry) dput(dentry); @@ -596,7 +555,6 @@ int autofs_expire_run(struct super_block *sb, pkt.len = dentry->d_name.len; memcpy(pkt.name, dentry->d_name.name, pkt.len); pkt.name[pkt.len] = '\0'; - dput(dentry); if (copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire))) ret = -EFAULT; @@ -609,6 +567,8 @@ int autofs_expire_run(struct super_block *sb, complete_all(&ino->expire_complete); spin_unlock(&sbi->fs_lock); + dput(dentry); + return ret; } diff --git a/fs/autofs/init.c b/fs/autofs/init.c index c0c1db2cc6ea..1d644a35ffa0 100644 --- a/fs/autofs/init.c +++ b/fs/autofs/init.c @@ -1,25 +1,17 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include <linux/module.h> #include <linux/init.h> #include "autofs_i.h" -static struct dentry *autofs_mount(struct file_system_type *fs_type, - int flags, const char *dev_name, void *data) -{ - return mount_nodev(fs_type, flags, data, autofs_fill_super); -} - struct file_system_type autofs_fs_type = { .owner = THIS_MODULE, .name = "autofs", - .mount = autofs_mount, + .init_fs_context = autofs_init_fs_context, + .parameters = autofs_param_specs, .kill_sb = autofs_kill_sb, }; MODULE_ALIAS_FS("autofs"); @@ -46,4 +38,5 @@ static void __exit exit_autofs_fs(void) module_init(init_autofs_fs) module_exit(exit_autofs_fs) +MODULE_DESCRIPTION("Kernel automounter support"); MODULE_LICENSE("GPL"); diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c index 0e8ea2d9a2bb..b932b1719dfc 100644 --- a/fs/autofs/inode.c +++ b/fs/autofs/inode.c @@ -1,15 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 2005-2006 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include <linux/seq_file.h> #include <linux/pagemap.h> -#include <linux/parser.h> #include "autofs_i.h" @@ -23,6 +19,8 @@ struct autofs_info *autofs_new_ino(struct autofs_sb_info *sbi) INIT_LIST_HEAD(&ino->expiring); ino->last_used = jiffies; ino->sbi = sbi; + ino->exp_timeout = -1; + ino->count = 1; } return ino; } @@ -31,12 +29,13 @@ void autofs_clean_ino(struct autofs_info *ino) { ino->uid = GLOBAL_ROOT_UID; ino->gid = GLOBAL_ROOT_GID; + ino->exp_timeout = -1; ino->last_used = jiffies; } void autofs_free_ino(struct autofs_info *ino) { - kfree(ino); + kfree_rcu(ino, rcu); } void autofs_kill_sb(struct super_block *sb) @@ -56,7 +55,7 @@ void autofs_kill_sb(struct super_block *sb) } pr_debug("shutting down\n"); - kill_litter_super(sb); + kill_anon_super(sb); if (sbi) kfree_rcu(sbi, rcu); } @@ -82,18 +81,20 @@ static int autofs_show_options(struct seq_file *m, struct dentry *root) seq_printf(m, ",maxproto=%d", sbi->max_proto); if (autofs_type_offset(sbi->type)) - seq_printf(m, ",offset"); + seq_puts(m, ",offset"); else if (autofs_type_direct(sbi->type)) - seq_printf(m, ",direct"); + seq_puts(m, ",direct"); else - seq_printf(m, ",indirect"); + seq_puts(m, ",indirect"); if (sbi->flags & AUTOFS_SBI_STRICTEXPIRE) - seq_printf(m, ",strictexpire"); + seq_puts(m, ",strictexpire"); + if (sbi->flags & AUTOFS_SBI_IGNORE) + seq_puts(m, ",ignore"); #ifdef CONFIG_CHECKPOINT_RESTORE if (sbi->pipe) seq_printf(m, ",pipe_ino=%ld", file_inode(sbi->pipe)->i_ino); else - seq_printf(m, ",pipe_ino=-1"); + seq_puts(m, ",pipe_ino=-1"); #endif return 0; } @@ -110,182 +111,171 @@ static const struct super_operations autofs_sops = { .evict_inode = autofs_evict_inode, }; -enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto, - Opt_indirect, Opt_direct, Opt_offset, Opt_strictexpire}; - -static const match_table_t tokens = { - {Opt_fd, "fd=%u"}, - {Opt_uid, "uid=%u"}, - {Opt_gid, "gid=%u"}, - {Opt_pgrp, "pgrp=%u"}, - {Opt_minproto, "minproto=%u"}, - {Opt_maxproto, "maxproto=%u"}, - {Opt_indirect, "indirect"}, - {Opt_direct, "direct"}, - {Opt_offset, "offset"}, - {Opt_strictexpire, "strictexpire"}, - {Opt_err, NULL} +enum { + Opt_direct, + Opt_fd, + Opt_gid, + Opt_ignore, + Opt_indirect, + Opt_maxproto, + Opt_minproto, + Opt_offset, + Opt_pgrp, + Opt_strictexpire, + Opt_uid, }; -static int parse_options(char *options, - struct inode *root, int *pgrp, bool *pgrp_set, - struct autofs_sb_info *sbi) +const struct fs_parameter_spec autofs_param_specs[] = { + fsparam_flag ("direct", Opt_direct), + fsparam_fd ("fd", Opt_fd), + fsparam_gid ("gid", Opt_gid), + fsparam_flag ("ignore", Opt_ignore), + fsparam_flag ("indirect", Opt_indirect), + fsparam_u32 ("maxproto", Opt_maxproto), + fsparam_u32 ("minproto", Opt_minproto), + fsparam_flag ("offset", Opt_offset), + fsparam_u32 ("pgrp", Opt_pgrp), + fsparam_flag ("strictexpire", Opt_strictexpire), + fsparam_uid ("uid", Opt_uid), + {} +}; + +struct autofs_fs_context { + kuid_t uid; + kgid_t gid; + int pgrp; + bool pgrp_set; +}; + +/* + * Open the fd. We do it here rather than in get_tree so that it's done in the + * context of the system call that passed the data and not the one that + * triggered the superblock creation, lest the fd gets reassigned. + */ +static int autofs_parse_fd(struct fs_context *fc, struct autofs_sb_info *sbi, + struct fs_parameter *param, + struct fs_parse_result *result) { - char *p; - substring_t args[MAX_OPT_ARGS]; - int option; - int pipefd = -1; - kuid_t uid; - kgid_t gid; + struct file *pipe; + int ret; - root->i_uid = current_uid(); - root->i_gid = current_gid(); + if (param->type == fs_value_is_file) { + /* came through the new api */ + pipe = param->file; + param->file = NULL; + } else { + pipe = fget(result->uint_32); + } + if (!pipe) { + errorf(fc, "could not open pipe file descriptor"); + return -EBADF; + } - sbi->min_proto = AUTOFS_MIN_PROTO_VERSION; - sbi->max_proto = AUTOFS_MAX_PROTO_VERSION; + ret = autofs_check_pipe(pipe); + if (ret < 0) { + errorf(fc, "Invalid/unusable pipe"); + fput(pipe); + return -EBADF; + } - sbi->pipefd = -1; + autofs_set_packet_pipe_flags(pipe); - if (!options) - return 1; - - while ((p = strsep(&options, ",")) != NULL) { - int token; - - if (!*p) - continue; - - token = match_token(p, tokens, args); - switch (token) { - case Opt_fd: - if (match_int(args, &pipefd)) - return 1; - sbi->pipefd = pipefd; - break; - case Opt_uid: - if (match_int(args, &option)) - return 1; - uid = make_kuid(current_user_ns(), option); - if (!uid_valid(uid)) - return 1; - root->i_uid = uid; - break; - case Opt_gid: - if (match_int(args, &option)) - return 1; - gid = make_kgid(current_user_ns(), option); - if (!gid_valid(gid)) - return 1; - root->i_gid = gid; - break; - case Opt_pgrp: - if (match_int(args, &option)) - return 1; - *pgrp = option; - *pgrp_set = true; - break; - case Opt_minproto: - if (match_int(args, &option)) - return 1; - sbi->min_proto = option; - break; - case Opt_maxproto: - if (match_int(args, &option)) - return 1; - sbi->max_proto = option; - break; - case Opt_indirect: - set_autofs_type_indirect(&sbi->type); - break; - case Opt_direct: - set_autofs_type_direct(&sbi->type); - break; - case Opt_offset: - set_autofs_type_offset(&sbi->type); - break; - case Opt_strictexpire: - sbi->flags |= AUTOFS_SBI_STRICTEXPIRE; - break; - default: - return 1; - } + if (sbi->pipe) + fput(sbi->pipe); + + sbi->pipefd = result->uint_32; + sbi->pipe = pipe; + + return 0; +} + +static int autofs_parse_param(struct fs_context *fc, struct fs_parameter *param) +{ + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = fc->s_fs_info; + struct fs_parse_result result; + int opt; + + opt = fs_parse(fc, autofs_param_specs, param, &result); + if (opt < 0) + return opt; + + switch (opt) { + case Opt_fd: + return autofs_parse_fd(fc, sbi, param, &result); + case Opt_uid: + ctx->uid = result.uid; + break; + case Opt_gid: + ctx->gid = result.gid; + break; + case Opt_pgrp: + ctx->pgrp = result.uint_32; + ctx->pgrp_set = true; + break; + case Opt_minproto: + sbi->min_proto = result.uint_32; + break; + case Opt_maxproto: + sbi->max_proto = result.uint_32; + break; + case Opt_indirect: + set_autofs_type_indirect(&sbi->type); + break; + case Opt_direct: + set_autofs_type_direct(&sbi->type); + break; + case Opt_offset: + set_autofs_type_offset(&sbi->type); + break; + case Opt_strictexpire: + sbi->flags |= AUTOFS_SBI_STRICTEXPIRE; + break; + case Opt_ignore: + sbi->flags |= AUTOFS_SBI_IGNORE; } - return (sbi->pipefd < 0); + + return 0; } -int autofs_fill_super(struct super_block *s, void *data, int silent) +static struct autofs_sb_info *autofs_alloc_sbi(void) { - struct inode *root_inode; - struct dentry *root; - struct file *pipe; struct autofs_sb_info *sbi; - struct autofs_info *ino; - int pgrp = 0; - bool pgrp_set = false; - int ret = -EINVAL; sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) - return -ENOMEM; - pr_debug("starting up, sbi = %p\n", sbi); + return NULL; - s->s_fs_info = sbi; sbi->magic = AUTOFS_SBI_MAGIC; - sbi->pipefd = -1; - sbi->pipe = NULL; - sbi->exp_timeout = 0; - sbi->oz_pgrp = NULL; - sbi->sb = s; - sbi->version = 0; - sbi->sub_version = 0; sbi->flags = AUTOFS_SBI_CATATONIC; + sbi->min_proto = AUTOFS_MIN_PROTO_VERSION; + sbi->max_proto = AUTOFS_MAX_PROTO_VERSION; + sbi->pipefd = -1; + sbi->mnt_ns_id = to_ns_common(current->nsproxy->mnt_ns)->ns_id; + set_autofs_type_indirect(&sbi->type); - sbi->min_proto = 0; - sbi->max_proto = 0; mutex_init(&sbi->wq_mutex); mutex_init(&sbi->pipe_mutex); spin_lock_init(&sbi->fs_lock); - sbi->queues = NULL; spin_lock_init(&sbi->lookup_lock); INIT_LIST_HEAD(&sbi->active_list); INIT_LIST_HEAD(&sbi->expiring_list); - s->s_blocksize = 1024; - s->s_blocksize_bits = 10; - s->s_magic = AUTOFS_SUPER_MAGIC; - s->s_op = &autofs_sops; - s->s_d_op = &autofs_dentry_operations; - s->s_time_gran = 1; - - /* - * Get the root inode and dentry, but defer checking for errors. - */ - ino = autofs_new_ino(sbi); - if (!ino) { - ret = -ENOMEM; - goto fail_free; - } - root_inode = autofs_get_inode(s, S_IFDIR | 0755); - root = d_make_root(root_inode); - if (!root) - goto fail_ino; - pipe = NULL; - root->d_fsdata = ino; + return sbi; +} - /* Can this call block? */ - if (parse_options(data, root_inode, &pgrp, &pgrp_set, sbi)) { - pr_err("called with bogus options\n"); - goto fail_dput; - } +static int autofs_validate_protocol(struct fs_context *fc) +{ + struct autofs_sb_info *sbi = fc->s_fs_info; /* Test versions first */ if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION || sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) { - pr_err("kernel does not match daemon version " + errorf(fc, "kernel does not match daemon version " "daemon (%d, %d) kernel (%d, %d)\n", sbi->min_proto, sbi->max_proto, AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION); - goto fail_dput; + return -EINVAL; } /* Establish highest kernel protocol version */ @@ -293,62 +283,148 @@ int autofs_fill_super(struct super_block *s, void *data, int silent) sbi->version = AUTOFS_MAX_PROTO_VERSION; else sbi->version = sbi->max_proto; - sbi->sub_version = AUTOFS_PROTO_SUBVERSION; - - if (pgrp_set) { - sbi->oz_pgrp = find_get_pid(pgrp); - if (!sbi->oz_pgrp) { - pr_err("could not find process group %d\n", - pgrp); - goto fail_dput; - } - } else { - sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); + + switch (sbi->version) { + case 4: + sbi->sub_version = 7; + break; + case 5: + sbi->sub_version = AUTOFS_PROTO_SUBVERSION; + break; + default: + sbi->sub_version = 0; } - if (autofs_type_trigger(sbi->type)) - __managed_dentry_set_managed(root); + return 0; +} + +static int autofs_fill_super(struct super_block *s, struct fs_context *fc) +{ + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = s->s_fs_info; + struct inode *root_inode; + struct autofs_info *ino; + + pr_debug("starting up, sbi = %p\n", sbi); + + sbi->sb = s; + s->s_blocksize = 1024; + s->s_blocksize_bits = 10; + s->s_magic = AUTOFS_SUPER_MAGIC; + s->s_op = &autofs_sops; + set_default_d_op(s, &autofs_dentry_operations); + s->s_time_gran = 1; + + /* + * Get the root inode and dentry, but defer checking for errors. + */ + ino = autofs_new_ino(sbi); + if (!ino) + return -ENOMEM; + root_inode = autofs_get_inode(s, S_IFDIR | 0755); + if (!root_inode) + return -ENOMEM; + + root_inode->i_uid = ctx->uid; + root_inode->i_gid = ctx->gid; root_inode->i_fop = &autofs_root_operations; root_inode->i_op = &autofs_dir_inode_operations; + s->s_root = d_make_root(root_inode); + if (unlikely(!s->s_root)) { + autofs_free_ino(ino); + return -ENOMEM; + } + s->s_root->d_fsdata = ino; + + if (ctx->pgrp_set) { + sbi->oz_pgrp = find_get_pid(ctx->pgrp); + if (!sbi->oz_pgrp) + return invalf(fc, "Could not find process group %d", + ctx->pgrp); + } else + sbi->oz_pgrp = get_task_pid(current, PIDTYPE_PGID); + + if (autofs_type_trigger(sbi->type)) + /* s->s_root won't be contended so there's little to + * be gained by not taking the d_lock when setting + * d_flags, even when a lot mounts are being done. + */ + managed_dentry_set_managed(s->s_root); + pr_debug("pipe fd = %d, pgrp = %u\n", sbi->pipefd, pid_nr(sbi->oz_pgrp)); - pipe = fget(sbi->pipefd); - if (!pipe) { - pr_err("could not open pipe file descriptor\n"); - goto fail_put_pid; - } - ret = autofs_prepare_pipe(pipe); - if (ret < 0) - goto fail_fput; - sbi->pipe = pipe; sbi->flags &= ~AUTOFS_SBI_CATATONIC; + return 0; +} - /* - * Success! Install the root dentry now to indicate completion. - */ - s->s_root = root; +/* + * Validate the parameters and then request a superblock. + */ +static int autofs_get_tree(struct fs_context *fc) +{ + struct autofs_sb_info *sbi = fc->s_fs_info; + int ret; + + ret = autofs_validate_protocol(fc); + if (ret) + return ret; + + if (sbi->pipefd < 0) + return invalf(fc, "No control pipe specified"); + + return get_tree_nodev(fc, autofs_fill_super); +} + +static void autofs_free_fc(struct fs_context *fc) +{ + struct autofs_fs_context *ctx = fc->fs_private; + struct autofs_sb_info *sbi = fc->s_fs_info; + + if (sbi) { + if (sbi->pipe) + fput(sbi->pipe); + kfree(sbi); + } + kfree(ctx); +} + +static const struct fs_context_operations autofs_context_ops = { + .free = autofs_free_fc, + .parse_param = autofs_parse_param, + .get_tree = autofs_get_tree, +}; + +/* + * Set up the filesystem mount context. + */ +int autofs_init_fs_context(struct fs_context *fc) +{ + struct autofs_fs_context *ctx; + struct autofs_sb_info *sbi; + + ctx = kzalloc(sizeof(struct autofs_fs_context), GFP_KERNEL); + if (!ctx) + goto nomem; + + ctx->uid = current_uid(); + ctx->gid = current_gid(); + + sbi = autofs_alloc_sbi(); + if (!sbi) + goto nomem_ctx; + + fc->fs_private = ctx; + fc->s_fs_info = sbi; + fc->ops = &autofs_context_ops; return 0; - /* - * Failure ... clean up. - */ -fail_fput: - pr_err("pipe file descriptor does not contain proper ops\n"); - fput(pipe); -fail_put_pid: - put_pid(sbi->oz_pgrp); -fail_dput: - dput(root); - goto fail_free; -fail_ino: - autofs_free_ino(ino); -fail_free: - kfree(sbi); - s->s_fs_info = NULL; - return ret; +nomem_ctx: + kfree(ctx); +nomem: + return -ENOMEM; } struct inode *autofs_get_inode(struct super_block *sb, umode_t mode) @@ -363,7 +439,7 @@ struct inode *autofs_get_inode(struct super_block *sb, umode_t mode) inode->i_uid = d_inode(sb->s_root)->i_uid; inode->i_gid = d_inode(sb->s_root)->i_gid; } - inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + simple_inode_init_ts(inode); inode->i_ino = get_next_ino(); if (S_ISDIR(mode)) { diff --git a/fs/autofs/root.c b/fs/autofs/root.c index 1246f396bf0e..2c31002b314a 100644 --- a/fs/autofs/root.c +++ b/fs/autofs/root.c @@ -1,11 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org> * Copyright 2001-2006 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include <linux/capability.h> @@ -13,10 +10,13 @@ #include "autofs_i.h" -static int autofs_dir_symlink(struct inode *, struct dentry *, const char *); +static int autofs_dir_permission(struct mnt_idmap *, struct inode *, int); +static int autofs_dir_symlink(struct mnt_idmap *, struct inode *, + struct dentry *, const char *); static int autofs_dir_unlink(struct inode *, struct dentry *); static int autofs_dir_rmdir(struct inode *, struct dentry *); -static int autofs_dir_mkdir(struct inode *, struct dentry *, umode_t); +static struct dentry *autofs_dir_mkdir(struct mnt_idmap *, struct inode *, + struct dentry *, umode_t); static long autofs_root_ioctl(struct file *, unsigned int, unsigned long); #ifdef CONFIG_COMPAT static long autofs_root_compat_ioctl(struct file *, @@ -51,6 +51,7 @@ const struct file_operations autofs_dir_operations = { const struct inode_operations autofs_dir_inode_operations = { .lookup = autofs_lookup, + .permission = autofs_dir_permission, .unlink = autofs_dir_unlink, .symlink = autofs_dir_symlink, .mkdir = autofs_dir_mkdir, @@ -63,44 +64,22 @@ const struct dentry_operations autofs_dentry_operations = { .d_release = autofs_dentry_release, }; -static void autofs_add_active(struct dentry *dentry) -{ - struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); - struct autofs_info *ino; - - ino = autofs_dentry_ino(dentry); - if (ino) { - spin_lock(&sbi->lookup_lock); - if (!ino->active_count) { - if (list_empty(&ino->active)) - list_add(&ino->active, &sbi->active_list); - } - ino->active_count++; - spin_unlock(&sbi->lookup_lock); - } -} - static void autofs_del_active(struct dentry *dentry) { struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); struct autofs_info *ino; ino = autofs_dentry_ino(dentry); - if (ino) { - spin_lock(&sbi->lookup_lock); - ino->active_count--; - if (!ino->active_count) { - if (!list_empty(&ino->active)) - list_del_init(&ino->active); - } - spin_unlock(&sbi->lookup_lock); - } + spin_lock(&sbi->lookup_lock); + list_del_init(&ino->active); + spin_unlock(&sbi->lookup_lock); } static int autofs_dir_open(struct inode *inode, struct file *file) { struct dentry *dentry = file->f_path.dentry; struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); + struct autofs_info *ino = autofs_dentry_ino(dentry); pr_debug("file=%p dentry=%p %pd\n", file, dentry, dentry); @@ -117,7 +96,7 @@ static int autofs_dir_open(struct inode *inode, struct file *file) * it. */ spin_lock(&sbi->lookup_lock); - if (!path_is_mountpoint(&file->f_path) && simple_empty(dentry)) { + if (!path_is_mountpoint(&file->f_path) && autofs_empty(ino)) { spin_unlock(&sbi->lookup_lock); return -ENOENT; } @@ -312,9 +291,26 @@ static struct dentry *autofs_mountpoint_changed(struct path *path) struct dentry *dentry = path->dentry; struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb); - /* - * If this is an indirect mount the dentry could have gone away - * as a result of an expire and a new one created. + /* If this is an indirect mount the dentry could have gone away + * and a new one created. + * + * This is unusual and I can't remember the case for which it + * was originally added now. But an example of how this can + * happen is an autofs indirect mount that has the "browse" + * option set and also has the "symlink" option in the autofs + * map entry. In this case the daemon will remove the browse + * directory and create a symlink as the mount leaving the + * struct path stale. + * + * Another not so obvious case is when a mount in an autofs + * indirect mount that uses the "nobrowse" option is being + * expired at the same time as a path walk. If the mount has + * been umounted but the mount point directory seen before + * becoming unhashed (during a lockless path walk) when a stat + * family system call is made the mount won't be re-mounted as + * it should. In this case the mount point that's been removed + * (by the daemon) will be stale and the a new mount point + * dentry created. */ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) { struct dentry *parent = dentry->d_parent; @@ -345,6 +341,14 @@ static struct vfsmount *autofs_d_automount(struct path *path) if (autofs_oz_mode(sbi)) return NULL; + /* Refuse to trigger mount if current namespace is not the owner + * and the mount is propagation private. + */ + if (sbi->mnt_ns_id != to_ns_common(current->nsproxy->mnt_ns)->ns_id) { + if (vfsmount_to_propagation_flags(path->mnt) & MS_PRIVATE) + return ERR_PTR(-EPERM); + } + /* * If an expire request is pending everyone must wait. * If the expire fails we're still mounted so continue @@ -386,7 +390,7 @@ static struct vfsmount *autofs_d_automount(struct path *path) * the mount never trigger mounts themselves (they have an * autofs trigger mount mounted on them). But v4 pseudo direct * mounts do need the leaves to trigger mounts. In this case - * we have no choice but to use the list_empty() check and + * we have no choice but to use the autofs_empty() check and * require user space behave. */ if (sbi->version > 4) { @@ -395,7 +399,7 @@ static struct vfsmount *autofs_d_automount(struct path *path) goto done; } } else { - if (!simple_empty(dentry)) { + if (!autofs_empty(ino)) { spin_unlock(&sbi->fs_lock); goto done; } @@ -450,9 +454,8 @@ static int autofs_d_manage(const struct path *path, bool rcu_walk) if (rcu_walk) { /* We don't need fs_lock in rcu_walk mode, - * just testing 'AUTOFS_INFO_NO_RCU' is enough. - * simple_empty() takes a spinlock, so leave it - * to last. + * just testing 'AUTOFS_INF_WANT_EXPIRE' is enough. + * * We only return -EISDIR when certain this isn't * a mount-trap. */ @@ -465,9 +468,7 @@ static int autofs_d_manage(const struct path *path, bool rcu_walk) inode = d_inode_rcu(dentry); if (inode && S_ISLNK(inode->i_mode)) return -EISDIR; - if (list_empty(&dentry->d_subdirs)) - return 0; - if (!simple_empty(dentry)) + if (!autofs_empty(ino)) return -EISDIR; return 0; } @@ -487,7 +488,7 @@ static int autofs_d_manage(const struct path *path, bool rcu_walk) * we can avoid needless calls ->d_automount() and avoid * an incorrect ELOOP error return. */ - if ((!path_is_mountpoint(path) && !simple_empty(dentry)) || + if ((!path_is_mountpoint(path) && !autofs_empty(ino)) || (d_really_is_positive(dentry) && d_is_symlink(dentry))) status = -EISDIR; } @@ -530,28 +531,50 @@ static struct dentry *autofs_lookup(struct inode *dir, if (!autofs_oz_mode(sbi) && !IS_ROOT(dentry->d_parent)) return ERR_PTR(-ENOENT); - /* Mark entries in the root as mount triggers */ - if (IS_ROOT(dentry->d_parent) && - autofs_type_indirect(sbi->type)) - __managed_dentry_set_managed(dentry); - ino = autofs_new_ino(sbi); if (!ino) return ERR_PTR(-ENOMEM); + spin_lock(&sbi->lookup_lock); + spin_lock(&dentry->d_lock); + /* Mark entries in the root as mount triggers */ + if (IS_ROOT(dentry->d_parent) && + autofs_type_indirect(sbi->type)) + __managed_dentry_set_managed(dentry); dentry->d_fsdata = ino; ino->dentry = dentry; - autofs_add_active(dentry); + list_add(&ino->active, &sbi->active_list); + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dentry->d_lock); } return NULL; } -static int autofs_dir_symlink(struct inode *dir, - struct dentry *dentry, - const char *symname) +static int autofs_dir_permission(struct mnt_idmap *idmap, + struct inode *inode, int mask) +{ + if (mask & MAY_WRITE) { + struct autofs_sb_info *sbi = autofs_sbi(inode->i_sb); + + if (!autofs_oz_mode(sbi)) + return -EACCES; + + /* autofs_oz_mode() needs to allow path walks when the + * autofs mount is catatonic but the state of an autofs + * file system needs to be preserved over restarts. + */ + if (sbi->flags & AUTOFS_SBI_CATATONIC) + return -EACCES; + } + + return generic_permission(idmap, inode, mask); +} + +static int autofs_dir_symlink(struct mnt_idmap *idmap, + struct inode *dir, struct dentry *dentry, + const char *symname) { - struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; struct inode *inode; @@ -560,16 +583,6 @@ static int autofs_dir_symlink(struct inode *dir, pr_debug("%s <- %pd\n", symname, dentry); - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - BUG_ON(!ino); autofs_clean_ino(ino); @@ -589,15 +602,12 @@ static int autofs_dir_symlink(struct inode *dir, } inode->i_private = cp; inode->i_size = size; - d_add(dentry, inode); - dget(dentry); - atomic_inc(&ino->count); + d_make_persistent(dentry, inode); p_ino = autofs_dentry_ino(dentry->d_parent); - if (p_ino && !IS_ROOT(dentry)) - atomic_inc(&p_ino->count); + p_ino->count++; - dir->i_mtime = current_time(dir); + inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); return 0; } @@ -620,30 +630,16 @@ static int autofs_dir_symlink(struct inode *dir, static int autofs_dir_unlink(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); - struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - - if (atomic_dec_and_test(&ino->count)) { - p_ino = autofs_dentry_ino(dentry->d_parent); - if (p_ino && !IS_ROOT(dentry)) - atomic_dec(&p_ino->count); - } - dput(ino->dentry); + p_ino = autofs_dentry_ino(dentry->d_parent); + p_ino->count--; + d_make_discardable(dentry); d_inode(dentry)->i_size = 0; clear_nlink(d_inode(dentry)); - dir->i_mtime = current_time(dir); + inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); spin_lock(&sbi->lookup_lock); __autofs_add_expiring(dentry); @@ -683,7 +679,6 @@ static void autofs_set_leaf_automount_flags(struct dentry *dentry) static void autofs_clear_leaf_automount_flags(struct dentry *dentry) { - struct list_head *d_child; struct dentry *parent; /* flags for dentrys in the root are handled elsewhere */ @@ -696,10 +691,7 @@ static void autofs_clear_leaf_automount_flags(struct dentry *dentry) /* only consider parents below dentrys in the root */ if (IS_ROOT(parent->d_parent)) return; - d_child = &dentry->d_child; - /* Set parent managed if it's becoming empty */ - if (d_child->next == &parent->d_subdirs && - d_child->prev == &parent->d_subdirs) + if (autofs_dentry_ino(parent)->count == 2) managed_dentry_set_managed(parent); } @@ -711,21 +703,10 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) pr_debug("dentry %p, removing %pd\n", dentry, dentry); - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; + if (ino->count != 1) + return -ENOTEMPTY; spin_lock(&sbi->lookup_lock); - if (!simple_empty(dentry)) { - spin_unlock(&sbi->lookup_lock); - return -ENOTEMPTY; - } __autofs_add_expiring(dentry); d_drop(dentry); spin_unlock(&sbi->lookup_lock); @@ -733,12 +714,9 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) if (sbi->version < 5) autofs_clear_leaf_automount_flags(dentry); - if (atomic_dec_and_test(&ino->count)) { - p_ino = autofs_dentry_ino(dentry->d_parent); - if (p_ino && dentry->d_parent != dentry) - atomic_dec(&p_ino->count); - } - dput(ino->dentry); + p_ino = autofs_dentry_ino(dentry->d_parent); + p_ino->count--; + d_make_discardable(dentry); d_inode(dentry)->i_size = 0; clear_nlink(d_inode(dentry)); @@ -748,24 +726,15 @@ static int autofs_dir_rmdir(struct inode *dir, struct dentry *dentry) return 0; } -static int autofs_dir_mkdir(struct inode *dir, - struct dentry *dentry, umode_t mode) +static struct dentry *autofs_dir_mkdir(struct mnt_idmap *idmap, + struct inode *dir, struct dentry *dentry, + umode_t mode) { struct autofs_sb_info *sbi = autofs_sbi(dir->i_sb); struct autofs_info *ino = autofs_dentry_ino(dentry); struct autofs_info *p_ino; struct inode *inode; - if (!autofs_oz_mode(sbi)) - return -EACCES; - - /* autofs_oz_mode() needs to allow path walks when the - * autofs mount is catatonic but the state of an autofs - * file system needs to be preserved over restarts. - */ - if (sbi->flags & AUTOFS_SBI_CATATONIC) - return -EACCES; - pr_debug("dentry %p, creating %pd\n", dentry, dentry); BUG_ON(!ino); @@ -776,21 +745,18 @@ static int autofs_dir_mkdir(struct inode *dir, inode = autofs_get_inode(dir->i_sb, S_IFDIR | mode); if (!inode) - return -ENOMEM; - d_add(dentry, inode); + return ERR_PTR(-ENOMEM); if (sbi->version < 5) autofs_set_leaf_automount_flags(dentry); - dget(dentry); - atomic_inc(&ino->count); + d_make_persistent(dentry, inode); p_ino = autofs_dentry_ino(dentry->d_parent); - if (p_ino && !IS_ROOT(dentry)) - atomic_inc(&p_ino->count); + p_ino->count++; inc_nlink(dir); - dir->i_mtime = current_time(dir); + inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir)); - return 0; + return NULL; } /* Get/set timeout ioctl() operation */ diff --git a/fs/autofs/symlink.c b/fs/autofs/symlink.c index aad3902c0cc1..7ac67dc76039 100644 --- a/fs/autofs/symlink.c +++ b/fs/autofs/symlink.c @@ -1,9 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include "autofs_i.h" diff --git a/fs/autofs/waitq.c b/fs/autofs/waitq.c index 15a3e31d0904..33dd4660d82f 100644 --- a/fs/autofs/waitq.c +++ b/fs/autofs/waitq.c @@ -1,10 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved * Copyright 2001-2006 Ian Kent <raven@themaw.net> - * - * This file is part of the Linux kernel and is made available under - * the terms of the GNU General Public License, version 2, or at your - * option, any later version, incorporated herein by reference. */ #include <linux/sched/signal.h> @@ -33,10 +30,11 @@ void autofs_catatonic_mode(struct autofs_sb_info *sbi) while (wq) { nwq = wq->next; wq->status = -ENOENT; /* Magic is gone - report failure */ - kfree(wq->name.name); + kfree(wq->name.name - wq->offset); wq->name.name = NULL; - wq->wait_ctr--; - wake_up_interruptible(&wq->queue); + wake_up(&wq->queue); + if (!--wq->wait_ctr) + kfree(wq); wq = nwq; } fput(sbi->pipe); /* Close the pipe */ @@ -56,7 +54,7 @@ static int autofs_write(struct autofs_sb_info *sbi, mutex_lock(&sbi->pipe_mutex); while (bytes) { - wr = __kernel_write(file, data, bytes, &file->f_pos); + wr = __kernel_write(file, data, bytes, NULL); if (wr <= 0) break; data += wr; @@ -178,51 +176,6 @@ static void autofs_notify_daemon(struct autofs_sb_info *sbi, fput(pipe); } -static int autofs_getpath(struct autofs_sb_info *sbi, - struct dentry *dentry, char *name) -{ - struct dentry *root = sbi->sb->s_root; - struct dentry *tmp; - char *buf; - char *p; - int len; - unsigned seq; - -rename_retry: - buf = name; - len = 0; - - seq = read_seqbegin(&rename_lock); - rcu_read_lock(); - spin_lock(&sbi->fs_lock); - for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent) - len += tmp->d_name.len + 1; - - if (!len || --len > NAME_MAX) { - spin_unlock(&sbi->fs_lock); - rcu_read_unlock(); - if (read_seqretry(&rename_lock, seq)) - goto rename_retry; - return 0; - } - - *(buf + len) = '\0'; - p = buf + len - dentry->d_name.len; - strncpy(p, dentry->d_name.name, dentry->d_name.len); - - for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) { - *(--p) = '/'; - p -= tmp->d_name.len; - strncpy(p, tmp->d_name.name, tmp->d_name.len); - } - spin_unlock(&sbi->fs_lock); - rcu_read_unlock(); - if (read_seqretry(&rename_lock, seq)) - goto rename_retry; - - return len; -} - static struct autofs_wait_queue * autofs_find_wait(struct autofs_sb_info *sbi, const struct qstr *qstr) { @@ -355,6 +308,7 @@ int autofs_wait(struct autofs_sb_info *sbi, struct qstr qstr; char *name; int status, ret, type; + unsigned int offset = 0; pid_t pid; pid_t tgid; @@ -392,20 +346,23 @@ int autofs_wait(struct autofs_sb_info *sbi, return -ENOMEM; /* If this is a direct mount request create a dummy name */ - if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type)) + if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type)) { + qstr.name = name; qstr.len = sprintf(name, "%p", dentry); - else { - qstr.len = autofs_getpath(sbi, dentry, name); - if (!qstr.len) { + } else { + char *p = dentry_path_raw(dentry, name, NAME_MAX); + if (IS_ERR(p)) { kfree(name); return -ENOENT; } + qstr.name = ++p; // skip the leading slash + qstr.len = strlen(p); + offset = p - name; } - qstr.name = name; - qstr.hash = full_name_hash(dentry, name, qstr.len); + qstr.hash = full_name_hash(dentry, qstr.name, qstr.len); if (mutex_lock_interruptible(&sbi->wq_mutex)) { - kfree(qstr.name); + kfree(name); return -EINTR; } @@ -413,7 +370,7 @@ int autofs_wait(struct autofs_sb_info *sbi, if (ret <= 0) { if (ret != -EINTR) mutex_unlock(&sbi->wq_mutex); - kfree(qstr.name); + kfree(name); return ret; } @@ -421,7 +378,7 @@ int autofs_wait(struct autofs_sb_info *sbi, /* Create a new wait queue */ wq = kmalloc(sizeof(struct autofs_wait_queue), GFP_KERNEL); if (!wq) { - kfree(qstr.name); + kfree(name); mutex_unlock(&sbi->wq_mutex); return -ENOMEM; } @@ -433,6 +390,7 @@ int autofs_wait(struct autofs_sb_info *sbi, sbi->queues = wq; init_waitqueue_head(&wq->queue); memcpy(&wq->name, &qstr, sizeof(struct qstr)); + wq->offset = offset; wq->dev = autofs_get_dev(sbi); wq->ino = autofs_get_ino(sbi); wq->uid = current_uid(); @@ -472,7 +430,7 @@ int autofs_wait(struct autofs_sb_info *sbi, (unsigned long) wq->wait_queue_token, wq->name.len, wq->name.name, notify); mutex_unlock(&sbi->wq_mutex); - kfree(qstr.name); + kfree(name); } /* @@ -543,7 +501,7 @@ int autofs_wait_release(struct autofs_sb_info *sbi, } *wql = wq->next; /* Unlink from chain */ - kfree(wq->name.name); + kfree(wq->name.name - wq->offset); wq->name.name = NULL; /* Do not wait on this queue */ wq->status = status; wake_up(&wq->queue); |