diff options
Diffstat (limited to 'fs/namei.c')
-rw-r--r-- | fs/namei.c | 270 |
1 files changed, 216 insertions, 54 deletions
diff --git a/fs/namei.c b/fs/namei.c index d1e467b7b9de..8da39bd08b7d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -43,6 +43,9 @@ #include "internal.h" #include "mount.h" +#define CREATE_TRACE_POINTS +#include <trace/events/namei.h> + /* [Feb-1997 T. Schoebel-Theuer] * Fundamental changes in the pathname lookup mechanisms (namei) * were necessary because of omirr. The reason is that omirr needs @@ -377,9 +380,11 @@ EXPORT_SYMBOL(generic_permission); * flag in inode->i_opflags, that says "this has not special * permission function, use the fast case". */ -static inline int do_inode_permission(struct inode *inode, int mask) +static inline int do_inode_permission(struct vfsmount *mnt, struct inode *inode, int mask) { if (unlikely(!(inode->i_opflags & IOP_FASTPERM))) { + if (likely(mnt && inode->i_op->permission2)) + return inode->i_op->permission2(mnt, inode, mask); if (likely(inode->i_op->permission)) return inode->i_op->permission(inode, mask); @@ -403,7 +408,7 @@ static inline int do_inode_permission(struct inode *inode, int mask) * This does not check for a read-only file system. You probably want * inode_permission(). */ -int __inode_permission(struct inode *inode, int mask) +int __inode_permission2(struct vfsmount *mnt, struct inode *inode, int mask) { int retval; @@ -423,7 +428,7 @@ int __inode_permission(struct inode *inode, int mask) return -EACCES; } - retval = do_inode_permission(inode, mask); + retval = do_inode_permission(mnt, inode, mask); if (retval) return retval; @@ -431,7 +436,14 @@ int __inode_permission(struct inode *inode, int mask) if (retval) return retval; - return security_inode_permission(inode, mask); + retval = security_inode_permission(inode, mask); + return retval; +} +EXPORT_SYMBOL(__inode_permission2); + +int __inode_permission(struct inode *inode, int mask) +{ + return __inode_permission2(NULL, inode, mask); } EXPORT_SYMBOL(__inode_permission); @@ -466,14 +478,20 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask) * * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask. */ -int inode_permission(struct inode *inode, int mask) +int inode_permission2(struct vfsmount *mnt, struct inode *inode, int mask) { int retval; retval = sb_permission(inode->i_sb, inode, mask); if (retval) return retval; - return __inode_permission(inode, mask); + return __inode_permission2(mnt, inode, mask); +} +EXPORT_SYMBOL(inode_permission2); + +int inode_permission(struct inode *inode, int mask) +{ + return inode_permission2(NULL, inode, mask); } EXPORT_SYMBOL(inode_permission); @@ -786,6 +804,81 @@ static inline int d_revalidate(struct dentry *dentry, unsigned int flags) return 1; } +#define INIT_PATH_SIZE 64 + +static void success_walk_trace(struct nameidata *nd) +{ + struct path *pt = &nd->path; + struct inode *i = nd->inode; + char buf[INIT_PATH_SIZE], *try_buf; + int cur_path_size; + char *p; + + /* When eBPF/ tracepoint is disabled, keep overhead low. */ + if (!trace_inodepath_enabled()) + return; + + /* First try stack allocated buffer. */ + try_buf = buf; + cur_path_size = INIT_PATH_SIZE; + + while (cur_path_size <= PATH_MAX) { + /* Free previous heap allocation if we are now trying + * a second or later heap allocation. + */ + if (try_buf != buf) + kfree(try_buf); + + /* All but the first alloc are on the heap. */ + if (cur_path_size != INIT_PATH_SIZE) { + try_buf = kmalloc(cur_path_size, GFP_KERNEL); + if (!try_buf) { + try_buf = buf; + sprintf(try_buf, "error:buf_alloc_failed"); + break; + } + } + + p = d_path(pt, try_buf, cur_path_size); + + if (!IS_ERR(p)) { + char *end = mangle_path(try_buf, p, "\n"); + + if (end) { + try_buf[end - try_buf] = 0; + break; + } else { + /* On mangle errors, double path size + * till PATH_MAX. + */ + cur_path_size = cur_path_size << 1; + continue; + } + } + + if (PTR_ERR(p) == -ENAMETOOLONG) { + /* If d_path complains that name is too long, + * then double path size till PATH_MAX. + */ + cur_path_size = cur_path_size << 1; + continue; + } + + sprintf(try_buf, "error:d_path_failed_%lu", + -1 * PTR_ERR(p)); + break; + } + + if (cur_path_size > PATH_MAX) + sprintf(try_buf, "error:d_path_name_too_long"); + + trace_inodepath(i, try_buf); + + if (try_buf != buf) + kfree(try_buf); + return; +} + /** * complete_walk - successful completion of path walk * @nd: pointer nameidata @@ -808,15 +901,21 @@ static int complete_walk(struct nameidata *nd) return -ECHILD; } - if (likely(!(nd->flags & LOOKUP_JUMPED))) + if (likely(!(nd->flags & LOOKUP_JUMPED))) { + success_walk_trace(nd); return 0; + } - if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE))) + if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE))) { + success_walk_trace(nd); return 0; + } status = dentry->d_op->d_weak_revalidate(dentry, nd->flags); - if (status > 0) + if (status > 0) { + success_walk_trace(nd); return 0; + } if (!status) status = -ESTALE; @@ -1082,7 +1181,7 @@ const char *get_link(struct nameidata *nd) return ERR_PTR(error); nd->last_type = LAST_BIND; - res = inode->i_link; + res = READ_ONCE(inode->i_link); if (!res) { const char * (*get)(struct dentry *, struct inode *, struct delayed_call *); @@ -1707,13 +1806,13 @@ out: static inline int may_lookup(struct nameidata *nd) { if (nd->flags & LOOKUP_RCU) { - int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK); + int err = inode_permission2(nd->path.mnt, nd->inode, MAY_EXEC|MAY_NOT_BLOCK); if (err != -ECHILD) return err; if (unlazy_walk(nd)) return -ECHILD; } - return inode_permission(nd->inode, MAY_EXEC); + return inode_permission2(nd->path.mnt, nd->inode, MAY_EXEC); } static inline int handle_dots(struct nameidata *nd, int type) @@ -2489,6 +2588,7 @@ EXPORT_SYMBOL(vfs_path_lookup); /** * lookup_one_len - filesystem helper to lookup single pathname component * @name: pathname component to lookup + * @mnt: mount we are looking up on * @base: base directory to lookup from * @len: maximum length @len should be interpreted to * @@ -2497,7 +2597,7 @@ EXPORT_SYMBOL(vfs_path_lookup); * * The caller must hold base->i_mutex. */ -struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) +struct dentry *lookup_one_len2(const char *name, struct vfsmount *mnt, struct dentry *base, int len) { struct qstr this; unsigned int c; @@ -2531,12 +2631,18 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) return ERR_PTR(err); } - err = inode_permission(base->d_inode, MAY_EXEC); + err = inode_permission2(mnt, base->d_inode, MAY_EXEC); if (err) return ERR_PTR(err); return __lookup_hash(&this, base, 0); } +EXPORT_SYMBOL(lookup_one_len2); + +struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) +{ + return lookup_one_len2(name, NULL, base, len); +} EXPORT_SYMBOL(lookup_one_len); /** @@ -2814,7 +2920,7 @@ EXPORT_SYMBOL(__check_sticky); * 11. We don't allow removal of NFS sillyrenamed files; it's handled by * nfs_async_unlink(). */ -static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) +static int may_delete(struct vfsmount *mnt, struct inode *dir, struct dentry *victim, bool isdir) { struct inode *inode = d_backing_inode(victim); int error; @@ -2826,7 +2932,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) BUG_ON(victim->d_parent->d_inode != dir); audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + error = inode_permission2(mnt, dir, MAY_WRITE | MAY_EXEC); if (error) return error; if (IS_APPEND(dir)) @@ -2858,7 +2964,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) * 4. We should have write and exec permissions on dir * 5. We can't do it if dir is immutable (done in permission()) */ -static inline int may_create(struct inode *dir, struct dentry *child) +static inline int may_create(struct vfsmount *mnt, struct inode *dir, struct dentry *child) { struct user_namespace *s_user_ns; audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE); @@ -2870,7 +2976,7 @@ static inline int may_create(struct inode *dir, struct dentry *child) if (!kuid_has_mapping(s_user_ns, current_fsuid()) || !kgid_has_mapping(s_user_ns, current_fsgid())) return -EOVERFLOW; - return inode_permission(dir, MAY_WRITE | MAY_EXEC); + return inode_permission2(mnt, dir, MAY_WRITE | MAY_EXEC); } /* @@ -2917,10 +3023,10 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) } EXPORT_SYMBOL(unlock_rename); -int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, - bool want_excl) +int vfs_create2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, + umode_t mode, bool want_excl) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -2936,6 +3042,13 @@ int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_create2); + +int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, + bool want_excl) +{ + return vfs_create2(NULL, dir, dentry, mode, want_excl); +} EXPORT_SYMBOL(vfs_create); bool may_open_dev(const struct path *path) @@ -2947,6 +3060,7 @@ bool may_open_dev(const struct path *path) static int may_open(const struct path *path, int acc_mode, int flag) { struct dentry *dentry = path->dentry; + struct vfsmount *mnt = path->mnt; struct inode *inode = dentry->d_inode; int error; @@ -2971,7 +3085,7 @@ static int may_open(const struct path *path, int acc_mode, int flag) break; } - error = inode_permission(inode, MAY_OPEN | acc_mode); + error = inode_permission2(mnt, inode, MAY_OPEN | acc_mode); if (error) return error; @@ -3006,7 +3120,7 @@ static int handle_truncate(struct file *filp) if (!error) error = security_path_truncate(path); if (!error) { - error = do_truncate(path->dentry, 0, + error = do_truncate2(path->mnt, path->dentry, 0, ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, filp); } @@ -3033,7 +3147,7 @@ static int may_o_create(const struct path *dir, struct dentry *dentry, umode_t m !kgid_has_mapping(s_user_ns, current_fsgid())) return -EOVERFLOW; - error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); + error = inode_permission2(dir->mnt, dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); if (error) return error; @@ -3452,7 +3566,8 @@ struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag) int error; /* we want directory to be writable */ - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + error = inode_permission2(ERR_PTR(-EOPNOTSUPP), dir, + MAY_WRITE | MAY_EXEC); if (error) goto out_err; error = -EOPNOTSUPP; @@ -3730,9 +3845,9 @@ inline struct dentry *user_path_create(int dfd, const char __user *pathname, } EXPORT_SYMBOL(user_path_create); -int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +int vfs_mknod2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -3756,6 +3871,12 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_mknod2); + +int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +{ + return vfs_mknod2(NULL, dir, dentry, mode, dev); +} EXPORT_SYMBOL(vfs_mknod); static int may_mknod(umode_t mode) @@ -3798,12 +3919,12 @@ retry: goto out; switch (mode & S_IFMT) { case 0: case S_IFREG: - error = vfs_create(path.dentry->d_inode,dentry,mode,true); + error = vfs_create2(path.mnt, path.dentry->d_inode,dentry,mode,true); if (!error) ima_post_path_mknod(dentry); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(path.dentry->d_inode,dentry,mode, + error = vfs_mknod2(path.mnt, path.dentry->d_inode,dentry,mode, new_decode_dev(dev)); break; case S_IFIFO: case S_IFSOCK: @@ -3824,9 +3945,9 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d return sys_mknodat(AT_FDCWD, filename, mode, dev); } -int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +int vfs_mkdir2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, umode_t mode) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); unsigned max_links = dir->i_sb->s_max_links; if (error) @@ -3848,6 +3969,12 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) fsnotify_mkdir(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_mkdir2); + +int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + return vfs_mkdir2(NULL, dir, dentry, mode); +} EXPORT_SYMBOL(vfs_mkdir); SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) @@ -3866,7 +3993,7 @@ retry: mode &= ~current_umask(); error = security_path_mkdir(&path, dentry, mode); if (!error) - error = vfs_mkdir(path.dentry->d_inode, dentry, mode); + error = vfs_mkdir2(path.mnt, path.dentry->d_inode, dentry, mode); done_path_create(&path, dentry); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; @@ -3880,9 +4007,9 @@ SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode) return sys_mkdirat(AT_FDCWD, pathname, mode); } -int vfs_rmdir(struct inode *dir, struct dentry *dentry) +int vfs_rmdir2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry) { - int error = may_delete(dir, dentry, 1); + int error = may_delete(mnt, dir, dentry, 1); if (error) return error; @@ -3917,6 +4044,12 @@ out: d_delete(dentry); return error; } +EXPORT_SYMBOL(vfs_rmdir2); + +int vfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + return vfs_rmdir2(NULL, dir, dentry); +} EXPORT_SYMBOL(vfs_rmdir); static long do_rmdir(int dfd, const char __user *pathname) @@ -3962,7 +4095,7 @@ retry: error = security_path_rmdir(&path, dentry); if (error) goto exit3; - error = vfs_rmdir(path.dentry->d_inode, dentry); + error = vfs_rmdir2(path.mnt, path.dentry->d_inode, dentry); exit3: dput(dentry); exit2: @@ -4001,10 +4134,10 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname) * be appropriate for callers that expect the underlying filesystem not * to be NFS exported. */ -int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) +int vfs_unlink2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) { struct inode *target = dentry->d_inode; - int error = may_delete(dir, dentry, 0); + int error = may_delete(mnt, dir, dentry, 0); if (error) return error; @@ -4039,6 +4172,12 @@ out: return error; } +EXPORT_SYMBOL(vfs_unlink2); + +int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) +{ + return vfs_unlink2(NULL, dir, dentry, delegated_inode); +} EXPORT_SYMBOL(vfs_unlink); /* @@ -4086,7 +4225,7 @@ retry_deleg: error = security_path_unlink(&path, dentry); if (error) goto exit2; - error = vfs_unlink(path.dentry->d_inode, dentry, &delegated_inode); + error = vfs_unlink2(path.mnt, path.dentry->d_inode, dentry, &delegated_inode); exit2: dput(dentry); } @@ -4136,9 +4275,9 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname) return do_unlinkat(AT_FDCWD, pathname); } -int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) +int vfs_symlink2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, const char *oldname) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -4155,6 +4294,12 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_symlink2); + +int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) +{ + return vfs_symlink2(NULL, dir, dentry, oldname); +} EXPORT_SYMBOL(vfs_symlink); SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, @@ -4177,7 +4322,7 @@ retry: error = security_path_symlink(&path, dentry, from->name); if (!error) - error = vfs_symlink(path.dentry->d_inode, dentry, from->name); + error = vfs_symlink2(path.mnt, path.dentry->d_inode, dentry, from->name); done_path_create(&path, dentry); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; @@ -4212,7 +4357,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn * be appropriate for callers that expect the underlying filesystem not * to be NFS exported. */ -int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) +int vfs_link2(struct vfsmount *mnt, struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) { struct inode *inode = old_dentry->d_inode; unsigned max_links = dir->i_sb->s_max_links; @@ -4221,7 +4366,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry); + error = may_create(mnt, dir, new_dentry); if (error) return error; @@ -4271,6 +4416,12 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de fsnotify_link(dir, inode, new_dentry); return error; } +EXPORT_SYMBOL(vfs_link2); + +int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) +{ + return vfs_link2(NULL, old_dentry, dir, new_dentry, delegated_inode); +} EXPORT_SYMBOL(vfs_link); /* @@ -4326,7 +4477,7 @@ retry: error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_dput; - error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); + error = vfs_link2(old_path.mnt, old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); out_dput: done_path_create(&new_path, new_dentry); if (delegated_inode) { @@ -4402,7 +4553,8 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ -int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, +int vfs_rename2(struct vfsmount *mnt, + struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, struct inode **delegated_inode, unsigned int flags) { @@ -4417,19 +4569,19 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (source == target) return 0; - error = may_delete(old_dir, old_dentry, is_dir); + error = may_delete(mnt, old_dir, old_dentry, is_dir); if (error) return error; if (!target) { - error = may_create(new_dir, new_dentry); + error = may_create(mnt, new_dir, new_dentry); } else { new_is_dir = d_is_dir(new_dentry); if (!(flags & RENAME_EXCHANGE)) - error = may_delete(new_dir, new_dentry, is_dir); + error = may_delete(mnt, new_dir, new_dentry, is_dir); else - error = may_delete(new_dir, new_dentry, new_is_dir); + error = may_delete(mnt, new_dir, new_dentry, new_is_dir); } if (error) return error; @@ -4443,12 +4595,12 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, */ if (new_dir != old_dir) { if (is_dir) { - error = inode_permission(source, MAY_WRITE); + error = inode_permission2(mnt, source, MAY_WRITE); if (error) return error; } if ((flags & RENAME_EXCHANGE) && new_is_dir) { - error = inode_permission(target, MAY_WRITE); + error = inode_permission2(mnt, target, MAY_WRITE); if (error) return error; } @@ -4525,6 +4677,14 @@ out: return error; } +EXPORT_SYMBOL(vfs_rename2); + +int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode, unsigned int flags) +{ + return vfs_rename2(NULL, old_dir, old_dentry, new_dir, new_dentry, delegated_inode, flags); +} EXPORT_SYMBOL(vfs_rename); SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, @@ -4638,7 +4798,7 @@ retry_deleg: &new_path, new_dentry, flags); if (error) goto exit5; - error = vfs_rename(old_path.dentry->d_inode, old_dentry, + error = vfs_rename2(old_path.mnt, old_path.dentry->d_inode, old_dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode, flags); exit5: @@ -4683,7 +4843,7 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna int vfs_whiteout(struct inode *dir, struct dentry *dentry) { - int error = may_create(dir, dentry); + int error = may_create(NULL, dir, dentry); if (error) return error; @@ -4720,9 +4880,11 @@ static int generic_readlink(struct dentry *dentry, char __user *buffer, { DEFINE_DELAYED_CALL(done); struct inode *inode = d_inode(dentry); - const char *link = inode->i_link; + const char *link; int res; + link = READ_ONCE(inode->i_link); + if (!link) { link = inode->i_op->get_link(dentry, inode, &done); if (IS_ERR(link)) |