diff --git a/Documentation/filesystems/path-lookup.rst b/Documentation/filesystems/path-lookup.rst index a6fa7619b69ec1..2b2df6aa54324b 100644 --- a/Documentation/filesystems/path-lookup.rst +++ b/Documentation/filesystems/path-lookup.rst @@ -1297,18 +1297,18 @@ to lookup: RCU-walk, REF-walk, and REF-walk with forced revalidation. yet. This is primarily used to tell the audit subsystem the full context of a particular access being audited. -``LOOKUP_ROOT`` indicates that the ``root`` field in the ``nameidata`` was +``ND_ROOT_PRESET`` indicates that the ``root`` field in the ``nameidata`` was provided by the caller, so it shouldn't be released when it is no longer needed. -``LOOKUP_JUMPED`` means that the current dentry was chosen not because +``ND_JUMPED`` means that the current dentry was chosen not because it had the right name but for some other reason. This happens when following "``..``", following a symlink to ``/``, crossing a mount point or accessing a "``/proc/$PID/fd/$FD``" symlink (also known as a "magic link"). In this case the filesystem has not been asked to revalidate the name (with ``d_revalidate()``). In such cases the inode may still need to be revalidated, so ``d_op->d_weak_revalidate()`` is called if -``LOOKUP_JUMPED`` is set when the look completes - which may be at the +``ND_JUMPED`` is set when the look completes - which may be at the final component or, when creating, unlinking, or renaming, at the penultimate component. Resolution-restriction flags diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 43b492d08dec3c..bf19fd6b86e71a 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -899,3 +899,12 @@ iov_iter_copy_from_user_atomic() is gone; use copy_page_from_iter_atomic(). The difference is copy_page_from_iter_atomic() advances the iterator and you don't need iov_iter_advance() after it. However, if you decide to use only a part of obtained data, you should do iov_iter_revert(). + +--- + +**mandatory** + +Calling conventions for file_open_root() changed; now it takes struct path * +instead of passing mount and dentry separately. For callers that used to +pass mnt_root> pair (i.e. the root of given mount), a new helper +is provided - file_open_root_mnt(). In-tree users adjusted. diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c index 328b16f99b3038..6ead1e24045765 100644 --- a/arch/um/drivers/mconsole_kern.c +++ b/arch/um/drivers/mconsole_kern.c @@ -141,7 +141,7 @@ void mconsole_proc(struct mc_request *req) mconsole_reply(req, "Proc not available", 1, 0); goto out; } - file = file_open_root(mnt->mnt_root, mnt, ptr, O_RDONLY, 0); + file = file_open_root_mnt(mnt, ptr, O_RDONLY, 0); if (IS_ERR(file)) { mconsole_reply(req, "Failed to open file", 1, 0); printk(KERN_ERR "open /proc/%s: %ld\n", ptr, PTR_ERR(file)); diff --git a/fs/coredump.c b/fs/coredump.c index c3d8fc14b99304..07afb5ddb1c4e7 100644 --- a/fs/coredump.c +++ b/fs/coredump.c @@ -755,8 +755,8 @@ void do_coredump(const kernel_siginfo_t *siginfo) task_lock(&init_task); get_fs_root(init_task.fs, &root); task_unlock(&init_task); - cprm.file = file_open_root(root.dentry, root.mnt, - cn.corename, open_flags, 0600); + cprm.file = file_open_root(&root, cn.corename, + open_flags, 0600); path_put(&root); } else { cprm.file = filp_open(cn.corename, open_flags, 0600); diff --git a/fs/fhandle.c b/fs/fhandle.c index ec6feeccc27615..6630c69c23a2a3 100644 --- a/fs/fhandle.c +++ b/fs/fhandle.c @@ -229,7 +229,7 @@ static long do_handle_open(int mountdirfd, struct file_handle __user *ufh, path_put(&path); return fd; } - file = file_open_root(path.dentry, path.mnt, "", open_flag, 0); + file = file_open_root(&path, "", open_flag, 0); if (IS_ERR(file)) { put_unused_fd(fd); retval = PTR_ERR(file); diff --git a/fs/internal.h b/fs/internal.h index 6aeae7ef33803d..3ce8edbaa3ca2f 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -129,7 +129,7 @@ struct open_flags { }; extern struct file *do_filp_open(int dfd, struct filename *pathname, const struct open_flags *op); -extern struct file *do_file_open_root(struct dentry *, struct vfsmount *, +extern struct file *do_file_open_root(const struct path *, const char *, const struct open_flags *); extern struct open_how build_open_how(int flags, umode_t mode); extern int build_open_flags(const struct open_how *how, struct open_flags *op); diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c index 90d255fbdd9b34..87aac4c72c37da 100644 --- a/fs/kernel_read_file.c +++ b/fs/kernel_read_file.c @@ -160,7 +160,7 @@ int kernel_read_file_from_path_initns(const char *path, loff_t offset, get_fs_root(init_task.fs, &root); task_unlock(&init_task); - file = file_open_root(root.dentry, root.mnt, path, O_RDONLY, 0); + file = file_open_root(&root, path, O_RDONLY, 0); path_put(&root); if (IS_ERR(file)) return PTR_ERR(file); diff --git a/fs/namei.c b/fs/namei.c index 79b0ff9b151e22..bf6d8a738c599e 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -554,7 +554,7 @@ struct nameidata { struct qstr last; struct path root; struct inode *inode; /* path.dentry.d_inode */ - unsigned int flags; + unsigned int flags, state; unsigned seq, m_seq, r_seq; int last_type; unsigned depth; @@ -573,10 +573,15 @@ struct nameidata { umode_t dir_mode; } __randomize_layout; -static void set_nameidata(struct nameidata *p, int dfd, struct filename *name) +#define ND_ROOT_PRESET 1 +#define ND_ROOT_GRABBED 2 +#define ND_JUMPED 4 + +static void __set_nameidata(struct nameidata *p, int dfd, struct filename *name) { struct nameidata *old = current->nameidata; p->stack = p->internal; + p->depth = 0; p->dfd = dfd; p->name = name; p->path.mnt = NULL; @@ -586,6 +591,17 @@ static void set_nameidata(struct nameidata *p, int dfd, struct filename *name) current->nameidata = p; } +static inline void set_nameidata(struct nameidata *p, int dfd, struct filename *name, + const struct path *root) +{ + __set_nameidata(p, dfd, name); + p->state = 0; + if (unlikely(root)) { + p->state = ND_ROOT_PRESET; + p->root = *root; + } +} + static void restore_nameidata(void) { struct nameidata *now = current->nameidata, *old = now->saved; @@ -645,9 +661,9 @@ static void terminate_walk(struct nameidata *nd) path_put(&nd->path); for (i = 0; i < nd->depth; i++) path_put(&nd->stack[i].link); - if (nd->flags & LOOKUP_ROOT_GRABBED) { + if (nd->state & ND_ROOT_GRABBED) { path_put(&nd->root); - nd->flags &= ~LOOKUP_ROOT_GRABBED; + nd->state &= ~ND_ROOT_GRABBED; } } else { nd->flags &= ~LOOKUP_RCU; @@ -710,9 +726,9 @@ static bool legitimize_root(struct nameidata *nd) if (!nd->root.mnt && (nd->flags & LOOKUP_IS_SCOPED)) return false; /* Nothing to do if nd->root is zero or is managed by the VFS user. */ - if (!nd->root.mnt || (nd->flags & LOOKUP_ROOT)) + if (!nd->root.mnt || (nd->state & ND_ROOT_PRESET)) return true; - nd->flags |= LOOKUP_ROOT_GRABBED; + nd->state |= ND_ROOT_GRABBED; return legitimize_path(nd, &nd->root, nd->root_seq); } @@ -849,8 +865,9 @@ static int complete_walk(struct nameidata *nd) * We don't want to zero nd->root for scoped-lookups or * externally-managed nd->root. */ - if (!(nd->flags & (LOOKUP_ROOT | LOOKUP_IS_SCOPED))) - nd->root.mnt = NULL; + if (!(nd->state & ND_ROOT_PRESET)) + if (!(nd->flags & LOOKUP_IS_SCOPED)) + nd->root.mnt = NULL; nd->flags &= ~LOOKUP_CACHED; if (!try_to_unlazy(nd)) return -ECHILD; @@ -877,7 +894,7 @@ static int complete_walk(struct nameidata *nd) return -EXDEV; } - if (likely(!(nd->flags & LOOKUP_JUMPED))) + if (likely(!(nd->state & ND_JUMPED))) return 0; if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE))) @@ -915,7 +932,7 @@ static int set_root(struct nameidata *nd) } while (read_seqcount_retry(&fs->seq, seq)); } else { get_fs_root(fs, &nd->root); - nd->flags |= LOOKUP_ROOT_GRABBED; + nd->state |= ND_ROOT_GRABBED; } return 0; } @@ -948,7 +965,7 @@ static int nd_jump_root(struct nameidata *nd) path_get(&nd->path); nd->inode = nd->path.dentry->d_inode; } - nd->flags |= LOOKUP_JUMPED; + nd->state |= ND_JUMPED; return 0; } @@ -976,7 +993,7 @@ int nd_jump_link(struct path *path) path_put(&nd->path); nd->path = *path; nd->inode = nd->path.dentry->d_inode; - nd->flags |= LOOKUP_JUMPED; + nd->state |= ND_JUMPED; return 0; err: @@ -1423,7 +1440,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, if (mounted) { path->mnt = &mounted->mnt; dentry = path->dentry = mounted->mnt.mnt_root; - nd->flags |= LOOKUP_JUMPED; + nd->state |= ND_JUMPED; *seqp = read_seqcount_begin(&dentry->d_seq); *inode = dentry->d_inode; /* @@ -1468,7 +1485,7 @@ static inline int handle_mounts(struct nameidata *nd, struct dentry *dentry, if (unlikely(nd->flags & LOOKUP_NO_XDEV)) ret = -EXDEV; else - nd->flags |= LOOKUP_JUMPED; + nd->state |= ND_JUMPED; } if (unlikely(ret)) { dput(path->dentry); @@ -2219,7 +2236,7 @@ static int link_path_walk(const char *name, struct nameidata *nd) case 2: if (name[1] == '.') { type = LAST_DOTDOT; - nd->flags |= LOOKUP_JUMPED; + nd->state |= ND_JUMPED; } break; case 1: @@ -2227,7 +2244,7 @@ static int link_path_walk(const char *name, struct nameidata *nd) } if (likely(type == LAST_NORM)) { struct dentry *parent = nd->path.dentry; - nd->flags &= ~LOOKUP_JUMPED; + nd->state &= ~ND_JUMPED; if (unlikely(parent->d_flags & DCACHE_OP_HASH)) { struct qstr this = { { .hash_len = hash_len }, .name = name }; err = parent->d_op->d_hash(parent, &this); @@ -2301,14 +2318,14 @@ static const char *path_init(struct nameidata *nd, unsigned flags) if (flags & LOOKUP_RCU) rcu_read_lock(); - nd->flags = flags | LOOKUP_JUMPED; - nd->depth = 0; + nd->flags = flags; + nd->state |= ND_JUMPED; nd->m_seq = __read_seqcount_begin(&mount_lock.seqcount); nd->r_seq = __read_seqcount_begin(&rename_lock.seqcount); smp_rmb(); - if (flags & LOOKUP_ROOT) { + if (nd->state & ND_ROOT_PRESET) { struct dentry *root = nd->root.dentry; struct inode *inode = root->d_inode; if (*s && unlikely(!d_can_lookup(root))) @@ -2383,7 +2400,7 @@ static const char *path_init(struct nameidata *nd, unsigned flags) nd->root_seq = nd->seq; } else { path_get(&nd->root); - nd->flags |= LOOKUP_ROOT_GRABBED; + nd->state |= ND_ROOT_GRABBED; } } return s; @@ -2422,7 +2439,7 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path ; if (!err && unlikely(nd->flags & LOOKUP_MOUNTPOINT)) { err = handle_lookup_down(nd); - nd->flags &= ~LOOKUP_JUMPED; // no d_weak_revalidate(), please... + nd->state &= ~ND_JUMPED; // no d_weak_revalidate(), please... } if (!err) err = complete_walk(nd); @@ -2446,11 +2463,7 @@ int filename_lookup(int dfd, struct filename *name, unsigned flags, struct nameidata nd; if (IS_ERR(name)) return PTR_ERR(name); - if (unlikely(root)) { - nd.root = *root; - flags |= LOOKUP_ROOT; - } - set_nameidata(&nd, dfd, name); + set_nameidata(&nd, dfd, name, root); retval = path_lookupat(&nd, flags | LOOKUP_RCU, path); if (unlikely(retval == -ECHILD)) retval = path_lookupat(&nd, flags, path); @@ -2491,7 +2504,7 @@ static struct filename *filename_parentat(int dfd, struct filename *name, if (IS_ERR(name)) return name; - set_nameidata(&nd, dfd, name); + set_nameidata(&nd, dfd, name, NULL); retval = path_parentat(&nd, flags | LOOKUP_RCU, parent); if (unlikely(retval == -ECHILD)) retval = path_parentat(&nd, flags, parent); @@ -3517,7 +3530,7 @@ struct file *do_filp_open(int dfd, struct filename *pathname, int flags = op->lookup_flags; struct file *filp; - set_nameidata(&nd, dfd, pathname); + set_nameidata(&nd, dfd, pathname, NULL); filp = path_openat(&nd, op, flags | LOOKUP_RCU); if (unlikely(filp == ERR_PTR(-ECHILD))) filp = path_openat(&nd, op, flags); @@ -3527,25 +3540,22 @@ struct file *do_filp_open(int dfd, struct filename *pathname, return filp; } -struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, +struct file *do_file_open_root(const struct path *root, const char *name, const struct open_flags *op) { struct nameidata nd; struct file *file; struct filename *filename; - int flags = op->lookup_flags | LOOKUP_ROOT; - - nd.root.mnt = mnt; - nd.root.dentry = dentry; + int flags = op->lookup_flags; - if (d_is_symlink(dentry) && op->intent & LOOKUP_OPEN) + if (d_is_symlink(root->dentry) && op->intent & LOOKUP_OPEN) return ERR_PTR(-ELOOP); filename = getname_kernel(name); if (IS_ERR(filename)) return ERR_CAST(filename); - set_nameidata(&nd, -1, filename); + set_nameidata(&nd, -1, filename, root); file = path_openat(&nd, op, flags | LOOKUP_RCU); if (unlikely(file == ERR_PTR(-ECHILD))) file = path_openat(&nd, op, flags); diff --git a/fs/nfs/nfstrace.h b/fs/nfs/nfstrace.h index 73080526f5f359..8a224871be74c6 100644 --- a/fs/nfs/nfstrace.h +++ b/fs/nfs/nfstrace.h @@ -280,8 +280,6 @@ TRACE_DEFINE_ENUM(LOOKUP_OPEN); TRACE_DEFINE_ENUM(LOOKUP_CREATE); TRACE_DEFINE_ENUM(LOOKUP_EXCL); TRACE_DEFINE_ENUM(LOOKUP_RENAME_TARGET); -TRACE_DEFINE_ENUM(LOOKUP_JUMPED); -TRACE_DEFINE_ENUM(LOOKUP_ROOT); TRACE_DEFINE_ENUM(LOOKUP_EMPTY); TRACE_DEFINE_ENUM(LOOKUP_DOWN); @@ -297,8 +295,6 @@ TRACE_DEFINE_ENUM(LOOKUP_DOWN); { LOOKUP_CREATE, "CREATE" }, \ { LOOKUP_EXCL, "EXCL" }, \ { LOOKUP_RENAME_TARGET, "RENAME_TARGET" }, \ - { LOOKUP_JUMPED, "JUMPED" }, \ - { LOOKUP_ROOT, "ROOT" }, \ { LOOKUP_EMPTY, "EMPTY" }, \ { LOOKUP_DOWN, "DOWN" }) diff --git a/fs/open.c b/fs/open.c index 1a325b3194dfeb..94bef26ff1b616 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1173,7 +1173,7 @@ struct file *filp_open(const char *filename, int flags, umode_t mode) } EXPORT_SYMBOL(filp_open); -struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, +struct file *file_open_root(const struct path *root, const char *filename, int flags, umode_t mode) { struct open_flags op; @@ -1181,7 +1181,7 @@ struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, int err = build_open_flags(&how, &op); if (err) return ERR_PTR(err); - return do_file_open_root(dentry, mnt, filename, &op); + return do_file_open_root(root, filename, &op); } EXPORT_SYMBOL(file_open_root); diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index dea0f5ee540cce..5d66faecd4ef06 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -1807,7 +1807,7 @@ static int process_sysctl_arg(char *param, char *val, panic("%s: Failed to allocate path for %s\n", __func__, param); strreplace(path, '.', '/'); - file = file_open_root((*proc_mnt)->mnt_root, *proc_mnt, path, O_WRONLY, 0); + file = file_open_root_mnt(*proc_mnt, path, O_WRONLY, 0); if (IS_ERR(file)) { err = PTR_ERR(file); if (err == -ENOENT) diff --git a/include/linux/fs.h b/include/linux/fs.h index 02bf57e6f6e2be..bb40ac8608a7b1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2768,8 +2768,14 @@ extern long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode); extern struct file *file_open_name(struct filename *, int, umode_t); extern struct file *filp_open(const char *, int, umode_t); -extern struct file *file_open_root(struct dentry *, struct vfsmount *, +extern struct file *file_open_root(const struct path *, const char *, int, umode_t); +static inline struct file *file_open_root_mnt(struct vfsmount *mnt, + const char *name, int flags, umode_t mode) +{ + return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root}, + name, flags, mode); +} extern struct file * dentry_open(const struct path *, int, const struct cred *); extern struct file * open_with_fake_path(const struct path *, int, struct inode*, const struct cred *); diff --git a/include/linux/namei.h b/include/linux/namei.h index b9605b2b46e714..be9a2b349ca7e8 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -36,9 +36,6 @@ enum {LAST_NORM, LAST_ROOT, LAST_DOT, LAST_DOTDOT}; /* internal use only */ #define LOOKUP_PARENT 0x0010 -#define LOOKUP_JUMPED 0x1000 -#define LOOKUP_ROOT 0x2000 -#define LOOKUP_ROOT_GRABBED 0x0008 /* Scoping flags for lookup. */ #define LOOKUP_NO_SYMLINKS 0x010000 /* No symlink crossing. */ diff --git a/kernel/usermode_driver.c b/kernel/usermode_driver.c index bb7bb3b478abfa..9dae1f6487136a 100644 --- a/kernel/usermode_driver.c +++ b/kernel/usermode_driver.c @@ -26,7 +26,7 @@ static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *na if (IS_ERR(mnt)) return mnt; - file = file_open_root(mnt->mnt_root, mnt, name, O_CREAT | O_WRONLY, 0700); + file = file_open_root_mnt(mnt, name, O_CREAT | O_WRONLY, 0700); if (IS_ERR(file)) { mntput(mnt); return ERR_CAST(file);