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Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 04/73] VFS: Make lookup_hash() return a struct path [ver #2] To: linux-fsdevel@vger.kernel.org, viro@ZenIV.linux.org.uk, valerie.aurora@gmail.com Cc: linux-kernel@vger.kernel.org, Jan Blunck (Original author), Valerie Aurora , David Howells (Forward porting) Date: Tue, 21 Feb 2012 17:57:52 +0000 Message-ID: <20120221175752.25235.8473.stgit@warthog.procyon.org.uk> In-Reply-To: <20120221175721.25235.8901.stgit@warthog.procyon.org.uk> References: <20120221175721.25235.8901.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9575 Lines: 319 Signed-off-by: Jan Blunck (Original author) Signed-off-by: Valerie Aurora Signed-off-by: David Howells (Forward porting) --- fs/namei.c | 121 +++++++++++++++++++++++++++++++----------------------------- 1 files changed, 62 insertions(+), 59 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 4dc0e1d..2d983f7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1766,9 +1766,20 @@ static struct dentry *__lookup_hash(struct qstr *name, * needs parent already locked. Doesn't follow mounts. * SMP-safe. */ -static struct dentry *lookup_hash(struct nameidata *nd) +static int lookup_hash(struct nameidata *nd, struct qstr *name, + struct path *path) { - return __lookup_hash(&nd->last, nd->path.dentry, nd); + struct dentry *result; + + result = __lookup_hash(name, nd->path.dentry, nd); + if (IS_ERR(result)) { + path->mnt = NULL; + path->dentry = NULL; + return PTR_ERR(result); + } + path->mnt = nd->path.mnt; + path->dentry = result; + return 0; } /** @@ -2098,7 +2109,6 @@ static struct file *do_last(struct nameidata *nd, struct path *path, const struct open_flags *op, const char *pathname) { struct dentry *dir = nd->path.dentry; - struct dentry *dentry; int open_flag = op->open_flag; int will_truncate = open_flag & O_TRUNC; int want_write = 0; @@ -2178,18 +2188,14 @@ static struct file *do_last(struct nameidata *nd, struct path *path, mutex_lock(&dir->d_inode->i_mutex); - dentry = lookup_hash(nd); - error = PTR_ERR(dentry); - if (IS_ERR(dentry)) { + error = lookup_hash(nd, &nd->last, path); + if (error) { mutex_unlock(&dir->d_inode->i_mutex); goto exit; } - path->dentry = dentry; - path->mnt = nd->path.mnt; - /* Negative dentry, just create the file */ - if (!dentry->d_inode) { + if (!path->dentry->d_inode) { umode_t mode = op->mode; if (!IS_POSIXACL(dir->d_inode)) mode &= ~current_umask(); @@ -2208,15 +2214,15 @@ static struct file *do_last(struct nameidata *nd, struct path *path, open_flag &= ~O_TRUNC; will_truncate = 0; acc_mode = MAY_OPEN; - error = security_path_mknod(&nd->path, dentry, mode, 0); + error = security_path_mknod(&nd->path, path->dentry, mode, 0); if (error) goto exit_mutex_unlock; - error = vfs_create(dir->d_inode, dentry, mode, nd); + error = vfs_create(dir->d_inode, path->dentry, mode, nd); if (error) goto exit_mutex_unlock; mutex_unlock(&dir->d_inode->i_mutex); dput(nd->path.dentry); - nd->path.dentry = dentry; + nd->path.dentry = path->dentry; goto common; } @@ -2395,8 +2401,8 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt, struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path, int is_dir) { - struct dentry *dentry = ERR_PTR(-EEXIST); struct nameidata nd; + struct path new_path; int error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd); if (error) return ERR_PTR(error); @@ -2405,6 +2411,7 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path * Yucky last component or no last component at all? * (foo/., foo/.., /////) */ + error = -EEXIST; if (nd.last_type != LAST_NORM) goto out; nd.flags &= ~LOOKUP_PARENT; @@ -2415,11 +2422,11 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path * Do the final lookup. */ mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); - dentry = lookup_hash(&nd); - if (IS_ERR(dentry)) + error = lookup_hash(&nd, &nd.last, &new_path); + if (error) goto fail; - if (dentry->d_inode) + if (new_path.dentry->d_inode) goto eexist; /* * Special case - lookup gave negative, but... we had foo/bar/ @@ -2428,20 +2435,20 @@ struct dentry *kern_path_create(int dfd, const char *pathname, struct path *path * been asking for (non-existent) directory. -ENOENT for you. */ if (unlikely(!is_dir && nd.last.name[nd.last.len])) { - dput(dentry); - dentry = ERR_PTR(-ENOENT); - goto fail; + error = -ENOENT; + goto fail_do_put; } *path = nd.path; - return dentry; + return new_path.dentry; eexist: - dput(dentry); - dentry = ERR_PTR(-EEXIST); + error = -EEXIST; +fail_do_put: + dput(new_path.dentry); fail: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); out: path_put(&nd.path); - return dentry; + return ERR_PTR(error); } EXPORT_SYMBOL(kern_path_create); @@ -2673,7 +2680,7 @@ static long do_rmdir(int dfd, const char __user *pathname) { int error = 0; char * name; - struct dentry *dentry; + struct path path; struct nameidata nd; error = user_path_parent(dfd, pathname, &nd, &name); @@ -2695,25 +2702,24 @@ static long do_rmdir(int dfd, const char __user *pathname) nd.flags &= ~LOOKUP_PARENT; mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); - dentry = lookup_hash(&nd); - error = PTR_ERR(dentry); - if (IS_ERR(dentry)) + error = lookup_hash(&nd, &nd.last, &path); + if (error) goto exit2; - if (!dentry->d_inode) { + if (!path.dentry->d_inode) { error = -ENOENT; goto exit3; } error = mnt_want_write(nd.path.mnt); if (error) goto exit3; - error = security_path_rmdir(&nd.path, dentry); + error = security_path_rmdir(&nd.path, path.dentry); if (error) goto exit4; - error = vfs_rmdir(nd.path.dentry->d_inode, dentry); + error = vfs_rmdir(nd.path.dentry->d_inode, path.dentry); exit4: mnt_drop_write(nd.path.mnt); exit3: - dput(dentry); + path_put_conditional(&path, &nd); exit2: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); exit1: @@ -2769,7 +2775,7 @@ static long do_unlinkat(int dfd, const char __user *pathname) { int error; char *name; - struct dentry *dentry; + struct path path; struct nameidata nd; struct inode *inode = NULL; @@ -2784,27 +2790,26 @@ static long do_unlinkat(int dfd, const char __user *pathname) nd.flags &= ~LOOKUP_PARENT; mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); - dentry = lookup_hash(&nd); - error = PTR_ERR(dentry); - if (!IS_ERR(dentry)) { + error = lookup_hash(&nd, &nd.last, &path); + if (!error) { /* Why not before? Because we want correct error value */ if (nd.last.name[nd.last.len]) goto slashes; - inode = dentry->d_inode; + inode = path.dentry->d_inode; if (!inode) goto slashes; ihold(inode); error = mnt_want_write(nd.path.mnt); if (error) goto exit2; - error = security_path_unlink(&nd.path, dentry); + error = security_path_unlink(&nd.path, path.dentry); if (error) goto exit3; - error = vfs_unlink(nd.path.dentry->d_inode, dentry); + error = vfs_unlink(nd.path.dentry->d_inode, path.dentry); exit3: mnt_drop_write(nd.path.mnt); exit2: - dput(dentry); + path_put_conditional(&path, &nd); } mutex_unlock(&nd.path.dentry->d_inode->i_mutex); if (inode) @@ -2815,8 +2820,8 @@ exit1: return error; slashes: - error = !dentry->d_inode ? -ENOENT : - S_ISDIR(dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR; + error = !path.dentry->d_inode ? -ENOENT : + S_ISDIR(path.dentry->d_inode->i_mode) ? -EISDIR : -ENOTDIR; goto exit2; } @@ -3156,7 +3161,7 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, int, newdfd, const char __user *, newname) { struct dentry *old_dir, *new_dir; - struct dentry *old_dentry, *new_dentry; + struct path old, new; struct dentry *trap; struct nameidata oldnd, newnd; char *from; @@ -3190,16 +3195,15 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, trap = lock_rename(new_dir, old_dir); - old_dentry = lookup_hash(&oldnd); - error = PTR_ERR(old_dentry); - if (IS_ERR(old_dentry)) + error = lookup_hash(&oldnd, &oldnd.last, &old); + if (error) goto exit3; /* source must exist */ error = -ENOENT; - if (!old_dentry->d_inode) + if (!old.dentry->d_inode) goto exit4; /* unless the source is a directory trailing slashes give -ENOTDIR */ - if (!S_ISDIR(old_dentry->d_inode->i_mode)) { + if (!S_ISDIR(old.dentry->d_inode->i_mode)) { error = -ENOTDIR; if (oldnd.last.name[oldnd.last.len]) goto exit4; @@ -3208,32 +3212,31 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, } /* source should not be ancestor of target */ error = -EINVAL; - if (old_dentry == trap) + if (old.dentry == trap) goto exit4; - new_dentry = lookup_hash(&newnd); - error = PTR_ERR(new_dentry); - if (IS_ERR(new_dentry)) + error = lookup_hash(&newnd, &newnd.last, &new); + if (error) goto exit4; /* target should not be an ancestor of source */ error = -ENOTEMPTY; - if (new_dentry == trap) + if (new.dentry == trap) goto exit5; error = mnt_want_write(oldnd.path.mnt); if (error) goto exit5; - error = security_path_rename(&oldnd.path, old_dentry, - &newnd.path, new_dentry); + error = security_path_rename(&oldnd.path, old.dentry, + &newnd.path, new.dentry); if (error) goto exit6; - error = vfs_rename(old_dir->d_inode, old_dentry, - new_dir->d_inode, new_dentry); + error = vfs_rename(old_dir->d_inode, old.dentry, + new_dir->d_inode, new.dentry); exit6: mnt_drop_write(oldnd.path.mnt); exit5: - dput(new_dentry); + path_put_conditional(&new, &newnd); exit4: - dput(old_dentry); + path_put_conditional(&old, &oldnd); exit3: unlock_rename(new_dir, old_dir); exit2: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/