diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/fs/namei.c b/fs/namei.c index dc42bfac5c57..a1cd129a2e8b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1469,7 +1469,7 @@ static int __traverse_mounts(struct path *path, unsigned flags, bool *jumped, int ret = 0; while (flags & DCACHE_MANAGED_DENTRY) { - /* Allow the filesystem to manage the transit without i_mutex + /* Allow the filesystem to manage the transit without i_rwsem * being held. */ if (flags & DCACHE_MANAGE_TRANSIT) { ret = path->dentry->d_op->d_manage(path, false); @@ -2908,7 +2908,8 @@ static int lookup_one_common(struct mnt_idmap *idmap, * @base: base directory to lookup from * * Look up a dentry by name in the dcache, returning NULL if it does not - * currently exist. The function does not try to create a dentry. + * currently exist. The function does not try to create a dentry and if one + * is found it doesn't try to revalidate it. * * Note that this routine is purely a helper for filesystem usage and should * not be called by generic code. It does no permission checking. @@ -2924,7 +2925,7 @@ struct dentry *try_lookup_noperm(struct qstr *name, struct dentry *base) if (err) return ERR_PTR(err); - return lookup_dcache(name, base, 0); + return d_lookup(base, name); } EXPORT_SYMBOL(try_lookup_noperm); @@ -2936,7 +2937,7 @@ EXPORT_SYMBOL(try_lookup_noperm); * Note that this routine is purely a helper for filesystem usage and should * not be called by generic code. It does no permission checking. * - * The caller must hold base->i_mutex. + * The caller must hold base->i_rwsem. */ struct dentry *lookup_noperm(struct qstr *name, struct dentry *base) { @@ -2962,7 +2963,7 @@ EXPORT_SYMBOL(lookup_noperm); * * This can be used for in-kernel filesystem clients such as file servers. * - * The caller must hold base->i_mutex. + * The caller must hold base->i_rwsem. */ struct dentry *lookup_one(struct mnt_idmap *idmap, struct qstr *name, struct dentry *base) @@ -3048,14 +3049,22 @@ EXPORT_SYMBOL(lookup_one_positive_unlocked); * Note that this routine is purely a helper for filesystem usage and should * not be called by generic code. It does no permission checking. * - * Unlike lookup_noperm, it should be called without the parent + * Unlike lookup_noperm(), it should be called without the parent * i_rwsem held, and will take the i_rwsem itself if necessary. + * + * Unlike try_lookup_noperm() it *does* revalidate the dentry if it already + * existed. */ struct dentry *lookup_noperm_unlocked(struct qstr *name, struct dentry *base) { struct dentry *ret; + int err; - ret = try_lookup_noperm(name, base); + err = lookup_noperm_common(name, base); + if (err) + return ERR_PTR(err); + + ret = lookup_dcache(name, base, 0); if (!ret) ret = lookup_slow(name, base, 0); return ret; @@ -3462,7 +3471,7 @@ static int may_open(struct mnt_idmap *idmap, const struct path *path, return -EACCES; break; default: - VFS_BUG_ON_INODE(1, inode); + VFS_BUG_ON_INODE(!IS_ANON_FILE(inode), inode); } error = inode_permission(idmap, inode, MAY_OPEN | acc_mode); @@ -4533,13 +4542,13 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname) * @dentry: victim * @delegated_inode: returns victim inode, if the inode is delegated. * - * The caller must hold dir->i_mutex. + * The caller must hold dir->i_rwsem exclusively. * * If vfs_unlink discovers a delegation, it will return -EWOULDBLOCK and * return a reference to the inode in delegated_inode. The caller * should then break the delegation on that inode and retry. Because * breaking a delegation may take a long time, the caller should drop - * dir->i_mutex before doing so. + * dir->i_rwsem before doing so. * * Alternatively, a caller may pass NULL for delegated_inode. This may * be appropriate for callers that expect the underlying filesystem not @@ -4598,7 +4607,7 @@ EXPORT_SYMBOL(vfs_unlink); /* * Make sure that the actual truncation of the file will occur outside its - * directory's i_mutex. Truncate can take a long time if there is a lot of + * directory's i_rwsem. Truncate can take a long time if there is a lot of * writeout happening, and we don't want to prevent access to the directory * while waiting on the I/O. */ @@ -4776,13 +4785,13 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn * @new_dentry: where to create the new link * @delegated_inode: returns inode needing a delegation break * - * The caller must hold dir->i_mutex + * The caller must hold dir->i_rwsem exclusively. * * If vfs_link discovers a delegation on the to-be-linked file in need * of breaking, it will return -EWOULDBLOCK and return a reference to the * inode in delegated_inode. The caller should then break the delegation * and retry. Because breaking a delegation may take a long time, the - * caller should drop the i_mutex before doing so. + * caller should drop the i_rwsem before doing so. * * Alternatively, a caller may pass NULL for delegated_inode. This may * be appropriate for callers that expect the underlying filesystem not @@ -4978,7 +4987,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * c) we may have to lock up to _four_ objects - parents and victim (if it exists), * and source (if it's a non-directory or a subdirectory that moves to * different parent). - * And that - after we got ->i_mutex on parents (until then we don't know + * And that - after we got ->i_rwsem on parents (until then we don't know * whether the target exists). Solution: try to be smart with locking * order for inodes. We rely on the fact that tree topology may change * only under ->s_vfs_rename_mutex _and_ that parent of the object we @@ -4990,15 +4999,16 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * has no more than 1 dentry. If "hybrid" objects will ever appear, * we'd better make sure that there's no link(2) for them. * d) conversion from fhandle to dentry may come in the wrong moment - when - * we are removing the target. Solution: we will have to grab ->i_mutex + * we are removing the target. Solution: we will have to grab ->i_rwsem * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on - * ->i_mutex on parents, which works but leads to some truly excessive + * ->i_rwsem on parents, which works but leads to some truly excessive * locking]. */ int vfs_rename(struct renamedata *rd) { int error; - struct inode *old_dir = rd->old_dir, *new_dir = rd->new_dir; + struct inode *old_dir = d_inode(rd->old_parent); + struct inode *new_dir = d_inode(rd->new_parent); struct dentry *old_dentry = rd->old_dentry; struct dentry *new_dentry = rd->new_dentry; struct inode **delegated_inode = rd->delegated_inode; @@ -5257,10 +5267,10 @@ retry_deleg: if (error) goto exit5; - rd.old_dir = old_path.dentry->d_inode; + rd.old_parent = old_path.dentry; rd.old_dentry = old_dentry; rd.old_mnt_idmap = mnt_idmap(old_path.mnt); - rd.new_dir = new_path.dentry->d_inode; + rd.new_parent = new_path.dentry; rd.new_dentry = new_dentry; rd.new_mnt_idmap = mnt_idmap(new_path.mnt); rd.delegated_inode = &delegated_inode; |