From: Jan Kara <jack@suse.cz>
To: Miklos Szeredi <miklos@szeredi.hu>
Cc: viro@ZenIV.linux.org.uk, torvalds@linux-foundation.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
hch@infradead.org, akpm@linux-foundation.org,
dhowells@redhat.com, zab@redhat.com, jack@suse.cz,
luto@amacapital.net, mszeredi@suse.cz
Subject: Re: [PATCH 07/11] vfs: add cross-rename
Date: Mon, 13 Jan 2014 08:52:27 +0100 [thread overview]
Message-ID: <20140113075227.GG3837@quack.suse.cz> (raw)
In-Reply-To: <1389219015-10980-8-git-send-email-miklos@szeredi.hu>
On Wed 08-01-14 23:10:11, Miklos Szeredi wrote:
> From: Miklos Szeredi <mszeredi@suse.cz>
>
> If flags contain RENAME_EXCHANGE then exchange source and destination files.
> There's no restriction on the type of the files; e.g. a directory can be
> exchanged with a symlink.
>
> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
> ---
> fs/dcache.c | 46 +++++++++++++++++----
> fs/namei.c | 107 +++++++++++++++++++++++++++++++++---------------
> include/linux/dcache.h | 1 +
> include/uapi/linux/fs.h | 1 +
> security/security.c | 16 ++++++++
> 5 files changed, 131 insertions(+), 40 deletions(-)
>
> diff --git a/fs/namei.c b/fs/namei.c
> index 3fbc95c72e31..97c6dbb47eca 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -4020,6 +4020,8 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
> const unsigned char *old_name;
> struct inode *source = old_dentry->d_inode;
> struct inode *target = new_dentry->d_inode;
> + bool new_is_dir = false;
> + unsigned max_links = new_dir->i_sb->s_max_links;
>
> if (source == target)
> return 0;
> @@ -4028,10 +4030,16 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
> if (error)
> return error;
>
> - if (!target)
> + if (!target) {
> error = may_create(new_dir, new_dentry);
> - else
> - error = may_delete(new_dir, new_dentry, is_dir);
> + } else {
> + new_is_dir = d_is_dir(new_dentry);
> +
> + if (!(flags & RENAME_EXCHANGE))
> + error = may_delete(new_dir, new_dentry, is_dir);
> + else
> + error = may_delete(new_dir, new_dentry, new_is_dir);
> + }
> if (error)
> return error;
>
> @@ -4042,10 +4050,17 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
> * If we are going to change the parent - check write permissions,
> * we'll need to flip '..'.
> */
> - if (is_dir && new_dir != old_dir) {
> - error = inode_permission(source, MAY_WRITE);
> - if (error)
> - return error;
> + if (new_dir != old_dir) {
> + if (is_dir) {
> + error = inode_permission(source, MAY_WRITE);
> + if (error)
> + return error;
> + }
> + if ((flags & RENAME_EXCHANGE) && new_is_dir) {
> + error = inode_permission(target, MAY_WRITE);
> + if (error)
> + return error;
> + }
> }
>
> error = security_inode_rename(old_dir, old_dentry, new_dir, new_dentry,
> @@ -4055,25 +4070,24 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
>
> old_name = fsnotify_oldname_init(old_dentry->d_name.name);
> dget(new_dentry);
> - if (!is_dir)
> - lock_two_nondirectories(source, target);
> - else if (target)
> - mutex_lock(&target->i_mutex);
> + if (!(flags & RENAME_EXCHANGE)) {
> + if (!is_dir)
> + lock_two_nondirectories(source, target);
> + else if (target)
> + mutex_lock(&target->i_mutex);
> + }
>
> error = -EBUSY;
> if (d_mountpoint(old_dentry) || d_mountpoint(new_dentry))
> goto out;
>
> - if (is_dir) {
> - unsigned max_links = new_dir->i_sb->s_max_links;
> -
> + if (max_links && new_dir != old_dir) {
> error = -EMLINK;
> - if (max_links && !target && new_dir != old_dir &&
> - new_dir->i_nlink >= max_links)
> + if (is_dir && !new_is_dir && new_dir->i_nlink >= max_links)
> + goto out;
> + if ((flags & RENAME_EXCHANGE) && !is_dir && new_is_dir &&
> + old_dir->i_nlink > max_links)
This should be >=, shouldn't it?
> goto out;
> -
> - if (target)
> - shrink_dcache_parent(new_dentry);
> } else {
> error = try_break_deleg(source, delegated_inode);
> if (error)
> @@ -4084,27 +4098,40 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
> goto out;
> }
> }
> + if (is_dir && !(flags & RENAME_EXCHANGE) && target)
> + shrink_dcache_parent(new_dentry);
> error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry,
> flags);
> if (error)
> goto out;
>
> - if (target) {
> + if (!(flags & RENAME_EXCHANGE) && target) {
> if (is_dir)
> target->i_flags |= S_DEAD;
> dont_mount(new_dentry);
> }
> - if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE))
> - d_move(old_dentry, new_dentry);
> + if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) {
> + if (!(flags & RENAME_EXCHANGE))
> + d_move(old_dentry, new_dentry);
> + else
> + d_exchange(old_dentry, new_dentry);
> + }
> out:
> - if (!is_dir)
> - unlock_two_nondirectories(source, target);
> - else if (target)
> - mutex_unlock(&target->i_mutex);
> + if (!(flags & RENAME_EXCHANGE)) {
> + if (!is_dir)
> + unlock_two_nondirectories(source, target);
> + else if (target)
> + mutex_unlock(&target->i_mutex);
> + }
> dput(new_dentry);
> - if (!error)
> + if (!error) {
> fsnotify_move(old_dir, new_dir, old_name, is_dir,
> - target, old_dentry);
> + !(flags & RENAME_EXCHANGE) ? target : NULL, old_dentry);
> + if (flags & RENAME_EXCHANGE) {
> + fsnotify_move(new_dir, old_dir, old_dentry->d_name.name,
> + new_is_dir, NULL, new_dentry);
> + }
> + }
> fsnotify_oldname_free(old_name);
>
> return error;
> @@ -4124,9 +4151,12 @@ SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
> bool should_retry = false;
> int error;
>
> - if (flags & ~RENAME_NOREPLACE)
> + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
> return -EOPNOTSUPP;
>
> + if ((flags & RENAME_NOREPLACE) && (flags & RENAME_EXCHANGE))
> + return -EINVAL;
> +
> retry:
> from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
> if (IS_ERR(from)) {
> @@ -4161,7 +4191,8 @@ retry:
>
> oldnd.flags &= ~LOOKUP_PARENT;
> newnd.flags &= ~LOOKUP_PARENT;
> - newnd.flags |= LOOKUP_RENAME_TARGET;
> + if (!(flags & RENAME_EXCHANGE))
> + newnd.flags |= LOOKUP_RENAME_TARGET;
>
> retry_deleg:
> trap = lock_rename(new_dir, old_dir);
> @@ -4181,12 +4212,23 @@ retry_deleg:
> error = -EEXIST;
> if ((flags & RENAME_NOREPLACE) && d_is_positive(new_dentry))
> goto exit5;
> + if (flags & RENAME_EXCHANGE) {
> + error = -ENOENT;
> + if (!new_dentry->d_inode)
> + goto exit5;
Should this be d_is_positive()?
Honza
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
next prev parent reply other threads:[~2014-01-13 7:52 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-08 22:10 [PATCH 00/11] cross rename v3 Miklos Szeredi
2014-01-08 22:10 ` [PATCH 01/11] vfs: add d_is_dir() Miklos Szeredi
2014-01-08 22:10 ` [PATCH 02/11] vfs: rename: move d_move() up Miklos Szeredi
2014-01-08 22:10 ` [PATCH 03/11] vfs: rename: use common code for dir and non-dir Miklos Szeredi
2014-01-08 22:10 ` [PATCH 04/11] vfs: add renameat2 syscall Miklos Szeredi
2014-01-14 22:11 ` Tetsuo Handa
2014-01-15 10:30 ` Miklos Szeredi
2014-01-15 13:50 ` Miklos Szeredi
2014-01-18 10:40 ` Tetsuo Handa
2014-01-08 22:10 ` [PATCH 05/11] vfs: add RENAME_NOREPLACE flag Miklos Szeredi
2014-01-15 18:19 ` J. Bruce Fields
2014-01-15 18:26 ` Andy Lutomirski
2014-01-15 23:33 ` J. Bruce Fields
2014-01-16 10:45 ` Miklos Szeredi
2014-01-15 18:35 ` Miklos Szeredi
2014-01-15 23:31 ` J. Bruce Fields
2014-01-08 22:10 ` [PATCH 06/11] security: add flags to rename hooks Miklos Szeredi
2014-01-08 22:10 ` [PATCH 07/11] vfs: add cross-rename Miklos Szeredi
2014-01-13 7:52 ` Jan Kara [this message]
2014-01-14 10:31 ` Miklos Szeredi
2014-01-14 12:47 ` Jan Kara
2014-01-08 22:10 ` [PATCH 08/11] ext4: rename: create ext4_renament structure for local vars Miklos Szeredi
2014-01-08 22:10 ` [PATCH 09/11] ext4: rename: move EMLINK check up Miklos Szeredi
2014-01-08 22:10 ` [PATCH 10/11] ext4: rename: split out helper functions Miklos Szeredi
2014-01-08 22:10 ` [PATCH 11/11] ext4: add cross rename support Miklos Szeredi
2014-01-13 12:25 ` Jan Kara
2014-01-14 10:35 ` Miklos Szeredi
2014-01-15 18:23 ` J. Bruce Fields
2014-01-15 18:31 ` Miklos Szeredi
2014-01-16 10:54 ` Miklos Szeredi
2014-01-16 14:48 ` J. Bruce Fields
2014-01-17 10:53 ` Michael Kerrisk (man-pages)
2014-01-17 14:41 ` Miklos Szeredi
2014-04-19 9:08 ` Michael Kerrisk (man-pages)
2014-04-19 12:08 ` Tetsuo Handa
2014-04-23 14:24 ` Miklos Szeredi
2014-04-24 11:20 ` [PATCH (for 3.15) 0/5] Fix cross rename race window for LSM Tetsuo Handa
2014-04-24 11:22 ` [PATCH (for 3.15) 1/5] LSM: Pass the rename flags to each LSM module Tetsuo Handa
2014-04-25 20:49 ` Casey Schaufler
2014-04-24 11:23 ` [PATCH (for 3.15) 2/5] SELinux: Handle the rename flags Tetsuo Handa
2014-04-24 11:24 ` [PATCH (for 3.15) 3/5] AppArmor: " Tetsuo Handa
2014-04-24 11:25 ` [PATCH (for 3.15) 4/5] TOMOYO: " Tetsuo Handa
2014-04-24 11:26 ` [PATCH (for 3.15) 5/5] LSM: Remove duplicated rename handling Tetsuo Handa
2014-05-01 11:58 ` [PATCH (for 3.15) 0/5] Fix cross rename race window for LSM Tetsuo Handa
2014-05-05 5:49 ` Tetsuo Handa
2014-05-11 15:53 ` Tetsuo Handa
2014-05-12 13:21 ` [PATCH (for 3.15) 0/5] Fix cross rename regressions " Tetsuo Handa
2014-05-12 13:22 ` [PATCH (for 3.15) 1/5] LSM: Pass the rename flags to each LSM module Tetsuo Handa
2014-05-19 12:19 ` John Johansen
2014-05-12 13:23 ` [PATCH (for 3.15) 2/5] SELinux: Handle the rename flags Tetsuo Handa
2014-05-12 13:24 ` [PATCH (for 3.15) 3/5] AppArmor: " Tetsuo Handa
2014-05-19 12:28 ` John Johansen
2014-05-12 13:25 ` [PATCH (for 3.15) 4/5] TOMOYO: " Tetsuo Handa
2014-05-12 13:25 ` [PATCH (for 3.15) 5/5] LSM: Remove duplicated rename handling Tetsuo Handa
2014-05-19 12:34 ` John Johansen
2014-04-23 14:21 ` [PATCH 11/11] ext4: add cross rename support Miklos Szeredi
2014-04-23 19:01 ` Michael Kerrisk (man-pages)
2014-01-17 22:08 ` J. Bruce Fields
2014-01-18 6:49 ` Miklos Szeredi
2014-01-18 16:27 ` J. Bruce Fields
2014-01-20 11:39 ` Miklos Szeredi
2014-01-20 11:50 ` Michael Kerrisk (man-pages)
2014-01-13 12:46 ` [PATCH 00/11] cross rename v3 Tetsuo Handa
2014-01-13 17:08 ` Miklos Szeredi
2014-01-13 22:03 ` Tetsuo Handa
2014-01-14 9:58 ` Miklos Szeredi
2014-01-14 13:03 ` Tetsuo Handa
2014-01-14 20:10 ` John Johansen
2014-01-14 20:53 ` Tetsuo Handa
2014-01-15 10:10 ` Miklos Szeredi
-- strict thread matches above, loose matches on Subject: below --
2013-11-20 13:01 [PATCH 00/11] cross rename v2 Miklos Szeredi
2013-11-20 13:01 ` [PATCH 07/11] vfs: add cross-rename Miklos Szeredi
2013-11-20 16:39 ` Andy Lutomirski
2013-11-20 16:44 ` Miklos Szeredi
2013-11-20 16:51 ` Andy Lutomirski
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