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From: Dave Hansen <haveblue@us.ibm.com>
To: akpm@osdl.org
Cc: linux-fsdevel@vger.kernel.org, hch@infradead.org,
	viro@ftp.linux.org.uk, Dave Hansen <haveblue@us.ibm.com>
Subject: [PATCH 04/26] filesystem helpers for custom 'struct file's
Date: Fri, 22 Jun 2007 13:03:08 -0700	[thread overview]
Message-ID: <20070622200308.A4245108@kernel> (raw)
In-Reply-To: <20070622200303.82D9CC3A@kernel>


Christoph H. says this stands on its own and can go in before the
rest of the r/o bind mount set.  

---

Some filesystems forego the vfs and may_open() and create their
own 'struct file's.

This patch creates a couple of helper functions which can be
used by these filesystems, and will provide a unified place
which the r/o bind mount code may patch.

Also, rename two existing, static-scope init_file() to less
generic names.

Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
---

 lxc-dave/fs/configfs/dir.c    |    5 +++--
 lxc-dave/fs/file_table.c      |   34 ++++++++++++++++++++++++++++++++++
 lxc-dave/fs/hugetlbfs/inode.c |   22 +++++++++-------------
 lxc-dave/fs/sysfs/dir.c       |    4 ++--
 lxc-dave/include/linux/file.h |    9 +++++++++
 lxc-dave/ipc/shm.c            |   13 +++++--------
 lxc-dave/mm/shmem.c           |    7 ++-----
 lxc-dave/mm/tiny-shmem.c      |   19 +++++++------------
 lxc-dave/net/socket.c         |   19 ++++++++++---------
 9 files changed, 81 insertions(+), 51 deletions(-)

diff -puN fs/configfs/dir.c~01-24-filesystem-helpers-for-custom-struct-file-s fs/configfs/dir.c
--- lxc/fs/configfs/dir.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/fs/configfs/dir.c	2007-06-21 23:23:13.000000000 -0700
@@ -142,7 +142,7 @@ static int init_dir(struct inode * inode
 	return 0;
 }
 
-static int init_file(struct inode * inode)
+static int configfs_init_file(struct inode * inode)
 {
 	inode->i_size = PAGE_SIZE;
 	inode->i_fop = &configfs_file_operations;
@@ -283,7 +283,8 @@ static int configfs_attach_attr(struct c
 
 	dentry->d_fsdata = configfs_get(sd);
 	sd->s_dentry = dentry;
-	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file);
+	error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
+				configfs_init_file);
 	if (error) {
 		configfs_put(sd);
 		return error;
diff -puN fs/file_table.c~01-24-filesystem-helpers-for-custom-struct-file-s fs/file_table.c
--- lxc/fs/file_table.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/fs/file_table.c	2007-06-21 23:23:13.000000000 -0700
@@ -139,6 +139,40 @@ fail:
 
 EXPORT_SYMBOL(get_empty_filp);
 
+struct file *alloc_file(struct vfsmount *mnt, struct dentry *dentry,
+		mode_t mode, const struct file_operations *fop)
+{
+	struct file *file;
+	struct path;
+
+	file = get_empty_filp();
+	if (!file)
+		return NULL;
+
+	init_file(file, mnt, dentry, mode, fop);
+	return file;
+}
+EXPORT_SYMBOL(alloc_file);
+
+/*
+ * Note: This is a crappy interface.  It is here to make
+ * merging with the existing users of get_empty_filp()
+ * who have complex failure logic easier.  All users
+ * of this should be moving to alloc_file().
+ */
+int init_file(struct file *file, struct vfsmount *mnt, struct dentry *dentry,
+	   mode_t mode, const struct file_operations *fop)
+{
+	int error = 0;
+	file->f_path.dentry = dentry;
+	file->f_path.mnt = mntget(mnt);
+	file->f_mapping = dentry->d_inode->i_mapping;
+	file->f_mode = mode;
+	file->f_op = fop;
+	return error;
+}
+EXPORT_SYMBOL(init_file);
+
 void fastcall fput(struct file *file)
 {
 	if (atomic_dec_and_test(&file->f_count))
diff -puN fs/hugetlbfs/inode.c~01-24-filesystem-helpers-for-custom-struct-file-s fs/hugetlbfs/inode.c
--- lxc/fs/hugetlbfs/inode.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/fs/hugetlbfs/inode.c	2007-06-21 23:23:13.000000000 -0700
@@ -759,16 +759,11 @@ struct file *hugetlb_zero_setup(size_t s
 	if (!dentry)
 		goto out_shm_unlock;
 
-	error = -ENFILE;
-	file = get_empty_filp();
-	if (!file)
-		goto out_dentry;
-
 	error = -ENOSPC;
 	inode = hugetlbfs_get_inode(root->d_sb, current->fsuid,
 				current->fsgid, S_IFREG | S_IRWXUGO, 0);
 	if (!inode)
-		goto out_file;
+		goto out_dentry;
 
 	error = -ENOMEM;
 	if (hugetlb_reserve_pages(inode, 0, size >> HPAGE_SHIFT))
@@ -777,17 +772,18 @@ struct file *hugetlb_zero_setup(size_t s
 	d_instantiate(dentry, inode);
 	inode->i_size = size;
 	inode->i_nlink = 0;
-	file->f_path.mnt = mntget(hugetlbfs_vfsmount);
-	file->f_path.dentry = dentry;
-	file->f_mapping = inode->i_mapping;
-	file->f_op = &hugetlbfs_file_operations;
-	file->f_mode = FMODE_WRITE | FMODE_READ;
+
+	error = -ENFILE;
+	file = alloc_file(hugetlbfs_vfsmount, dentry,
+			FMODE_WRITE | FMODE_READ,
+			&hugetlbfs_file_operations);
+	if (!file)
+		goto out_inode;
+
 	return file;
 
 out_inode:
 	iput(inode);
-out_file:
-	put_filp(file);
 out_dentry:
 	dput(dentry);
 out_shm_unlock:
diff -puN fs/sysfs/dir.c~01-24-filesystem-helpers-for-custom-struct-file-s fs/sysfs/dir.c
--- lxc/fs/sysfs/dir.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/fs/sysfs/dir.c	2007-06-21 23:23:13.000000000 -0700
@@ -134,7 +134,7 @@ static int init_dir(struct inode * inode
 	return 0;
 }
 
-static int init_file(struct inode * inode)
+static int sysfs_init_file(struct inode * inode)
 {
 	inode->i_size = PAGE_SIZE;
 	inode->i_fop = &sysfs_file_operations;
@@ -234,7 +234,7 @@ static int sysfs_attach_attr(struct sysf
                 attr = &bin_attr->attr;
         } else {
                 attr = sd->s_element;
-                init = init_file;
+		init = sysfs_init_file;
         }
 
 	dentry->d_fsdata = sysfs_get(sd);
diff -puN include/linux/file.h~01-24-filesystem-helpers-for-custom-struct-file-s include/linux/file.h
--- lxc/include/linux/file.h~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/include/linux/file.h	2007-06-21 23:23:13.000000000 -0700
@@ -62,6 +62,15 @@ extern struct kmem_cache *filp_cachep;
 extern void FASTCALL(__fput(struct file *));
 extern void FASTCALL(fput(struct file *));
 
+struct file_operations;
+struct vfsmount;
+struct dentry;
+extern int init_file(struct file *, struct vfsmount *mnt,
+		struct dentry *dentry, mode_t mode,
+		const struct file_operations *fop);
+extern struct file *alloc_file(struct vfsmount *, struct dentry *dentry,
+		mode_t mode, const struct file_operations *fop);
+
 static inline void fput_light(struct file *file, int fput_needed)
 {
 	if (unlikely(fput_needed))
diff -puN ipc/shm.c~01-24-filesystem-helpers-for-custom-struct-file-s ipc/shm.c
--- lxc/ipc/shm.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/ipc/shm.c	2007-06-21 23:23:13.000000000 -0700
@@ -899,7 +899,7 @@ long do_shmat(int shmid, char __user *sh
 		goto out_unlock;
 
 	path.dentry = dget(shp->shm_file->f_path.dentry);
-	path.mnt    = mntget(shp->shm_file->f_path.mnt);
+	path.mnt    = shp->shm_file->f_path.mnt;
 	shp->shm_nattch++;
 	size = i_size_read(path.dentry->d_inode);
 	shm_unlock(shp);
@@ -907,18 +907,16 @@ long do_shmat(int shmid, char __user *sh
 	err = -ENOMEM;
 	sfd = kzalloc(sizeof(*sfd), GFP_KERNEL);
 	if (!sfd)
-		goto out_put_path;
+		goto out_put_dentry;
 
 	err = -ENOMEM;
-	file = get_empty_filp();
+
+	file = alloc_file(path.mnt, path.dentry, f_mode, &shm_file_operations);
 	if (!file)
 		goto out_free;
 
-	file->f_op = &shm_file_operations;
 	file->private_data = sfd;
-	file->f_path = path;
 	file->f_mapping = shp->shm_file->f_mapping;
-	file->f_mode = f_mode;
 	sfd->id = shp->id;
 	sfd->ns = get_ipc_ns(ns);
 	sfd->file = shp->shm_file;
@@ -969,9 +967,8 @@ out_unlock:
 
 out_free:
 	kfree(sfd);
-out_put_path:
+out_put_dentry:
 	dput(path.dentry);
-	mntput(path.mnt);
 	goto out_nattch;
 }
 
diff -puN mm/shmem.c~01-24-filesystem-helpers-for-custom-struct-file-s mm/shmem.c
--- lxc/mm/shmem.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/mm/shmem.c	2007-06-21 23:23:13.000000000 -0700
@@ -2567,11 +2567,8 @@ struct file *shmem_file_setup(char *name
 	d_instantiate(dentry, inode);
 	inode->i_size = size;
 	inode->i_nlink = 0;	/* It is unlinked */
-	file->f_path.mnt = mntget(shm_mnt);
-	file->f_path.dentry = dentry;
-	file->f_mapping = inode->i_mapping;
-	file->f_op = &shmem_file_operations;
-	file->f_mode = FMODE_WRITE | FMODE_READ;
+	init_file(file, shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
+			&shmem_file_operations);
 	return file;
 
 close_file:
diff -puN mm/tiny-shmem.c~01-24-filesystem-helpers-for-custom-struct-file-s mm/tiny-shmem.c
--- lxc/mm/tiny-shmem.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/mm/tiny-shmem.c	2007-06-21 23:23:13.000000000 -0700
@@ -66,24 +66,19 @@ struct file *shmem_file_setup(char *name
 	if (!dentry)
 		goto put_memory;
 
-	error = -ENFILE;
-	file = get_empty_filp();
-	if (!file)
-		goto put_dentry;
-
 	error = -ENOSPC;
 	inode = ramfs_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0);
 	if (!inode)
-		goto close_file;
+		goto put_dentry;
 
 	d_instantiate(dentry, inode);
-	inode->i_nlink = 0;	/* It is unlinked */
+	error = -ENFILE;
+	file = alloc_file(shm_mnt, dentry, FMODE_WRITE | FMODE_READ,
+			&ramfs_file_operations);
+	if (!file)
+		goto put_dentry;
 
-	file->f_path.mnt = mntget(shm_mnt);
-	file->f_path.dentry = dentry;
-	file->f_mapping = inode->i_mapping;
-	file->f_op = &ramfs_file_operations;
-	file->f_mode = FMODE_WRITE | FMODE_READ;
+	inode->i_nlink = 0;	/* It is unlinked */
 
 	/* notify everyone as to the change of file size */
 	error = do_truncate(dentry, size, 0, file);
diff -puN net/socket.c~01-24-filesystem-helpers-for-custom-struct-file-s net/socket.c
--- lxc/net/socket.c~01-24-filesystem-helpers-for-custom-struct-file-s	2007-06-21 23:23:13.000000000 -0700
+++ lxc-dave/net/socket.c	2007-06-21 23:23:13.000000000 -0700
@@ -355,31 +355,32 @@ static int sock_alloc_fd(struct file **f
 
 static int sock_attach_fd(struct socket *sock, struct file *file)
 {
+	struct dentry *dentry;
 	struct qstr this;
 	char name[32];
 
 	this.len = sprintf(name, "[%lu]", SOCK_INODE(sock)->i_ino);
 	this.name = name;
 	this.hash = 0;
+	struct path;
 
-	file->f_path.dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
-	if (unlikely(!file->f_path.dentry))
+	dentry = d_alloc(sock_mnt->mnt_sb->s_root, &this);
+	if (unlikely(!dentry))
 		return -ENOMEM;
 
-	file->f_path.dentry->d_op = &sockfs_dentry_operations;
+	dentry->d_op = &sockfs_dentry_operations;
 	/*
 	 * We dont want to push this dentry into global dentry hash table.
 	 * We pretend dentry is already hashed, by unsetting DCACHE_UNHASHED
 	 * This permits a working /proc/$pid/fd/XXX on sockets
 	 */
-	file->f_path.dentry->d_flags &= ~DCACHE_UNHASHED;
-	d_instantiate(file->f_path.dentry, SOCK_INODE(sock));
-	file->f_path.mnt = mntget(sock_mnt);
-	file->f_mapping = file->f_path.dentry->d_inode->i_mapping;
-
+	dentry->d_flags &= ~DCACHE_UNHASHED;
+	d_instantiate(dentry, SOCK_INODE(sock));
+	init_file(file, sock_mnt, dentry, FMODE_READ | FMODE_WRITE,
+		&socket_file_ops);
+	SOCK_INODE(sock)->i_fop = &socket_file_ops;
 	sock->file = file;
 	file->f_op = SOCK_INODE(sock)->i_fop = &socket_file_ops;
-	file->f_mode = FMODE_READ | FMODE_WRITE;
 	file->f_flags = O_RDWR;
 	file->f_pos = 0;
 	file->private_data = sock;
_

  parent reply	other threads:[~2007-06-22 20:03 UTC|newest]

Thread overview: 83+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-06-22 20:03 [PATCH 00/26] Mount writer count and read-only bind mounts Dave Hansen
2007-06-22 20:03 ` [PATCH 01/26] document nlink function Dave Hansen
2007-06-23  7:36   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 02/26] ext3: remove extra IS_RDONLY() check Dave Hansen
2007-06-23  7:36   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 03/26] ext4: " Dave Hansen
2007-06-23  7:37   ` Christoph Hellwig
2007-06-22 20:03 ` Dave Hansen [this message]
2007-06-23  7:38   ` [PATCH 04/26] filesystem helpers for custom 'struct file's Christoph Hellwig
2007-06-25 14:53     ` Dave Hansen
2007-06-23 16:52   ` Andrew Morton
2007-06-25 15:37     ` Dave Hansen
2007-06-25 17:25       ` Andrew Morton
2007-06-25 17:32         ` Dave Hansen
2007-06-30  9:35           ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 05/26] r/o bind mounts: stub functions Dave Hansen
2007-06-23  7:39   ` Christoph Hellwig
2007-06-23 16:52   ` Andrew Morton
2007-06-25 15:49     ` Dave Hansen
2007-06-22 20:03 ` [PATCH 06/26] elevate write count open()'d files Dave Hansen
2007-06-23  7:40   ` Christoph Hellwig
2007-06-25 15:03     ` Dave Hansen
2007-06-22 20:03 ` [PATCH 07/26] r/o bind mounts: elevate write count for some ioctls Dave Hansen
2007-06-23  7:42   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 08/26] elevate writer count for chown and friends Dave Hansen
2007-06-23  7:43   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 09/26] make access() use mnt check Dave Hansen
2007-06-23  7:45   ` Christoph Hellwig
2007-06-25 18:27     ` Dave Hansen
2007-06-26 19:04       ` Dave Kleikamp
2007-06-30  9:37       ` Christoph Hellwig
2007-07-02 16:09         ` Dave Hansen
2007-06-22 20:03 ` [PATCH 10/26] elevate mnt writers for callers of vfs_mkdir() Dave Hansen
2007-06-23  7:45   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 11/26] elevate write count during entire ncp_ioctl() Dave Hansen
2007-06-22 20:03 ` [PATCH 12/26] elevate write count for link and symlink calls Dave Hansen
2007-06-22 20:03 ` [PATCH 13/26] elevate mount count for extended attributes Dave Hansen
2007-06-22 20:03 ` [PATCH 14/26] elevate write count for file_update_time() Dave Hansen
2007-06-23  7:46   ` Christoph Hellwig
2007-06-25 18:32     ` Dave Hansen
2007-06-30  9:38       ` Christoph Hellwig
2007-07-06 19:17     ` Dave Hansen
2007-06-22 20:03 ` [PATCH 15/26] mount_is_safe(): add comment Dave Hansen
2007-06-23  7:47   ` Christoph Hellwig
2007-06-25 15:10     ` Dave Hansen
2007-06-22 20:03 ` [PATCH 16/26] unix_find_other() elevate write count for touch_atime() Dave Hansen
2007-06-23  7:47   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 17/26] elevate write count over calls to vfs_rename() Dave Hansen
2007-06-23  7:49   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 18/26] nfs: check mnt instead of superblock directly Dave Hansen
2007-06-23  7:49   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 19/26] elevate writer count for do_sys_truncate() Dave Hansen
2007-06-23  7:49   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 20/26] elevate write count for do_utimes() Dave Hansen
2007-06-23  7:49   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 21/26] elevate write count for do_sys_utime() and touch_atime() Dave Hansen
2007-06-23  7:50   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 22/26] sys_mknodat(): elevate write count for vfs_mknod/create() Dave Hansen
2007-06-23  7:51   ` Christoph Hellwig
2007-06-25 15:19     ` Dave Hansen
2007-06-30  9:39       ` Christoph Hellwig
2007-07-02 23:31         ` Dave Hansen
2007-07-05 22:43         ` Dave Hansen
2007-07-07 18:25           ` Jan Engelhardt
2007-07-09 19:04             ` Dave Hansen
2007-07-11 10:22             ` Christoph Hellwig
2007-07-11 10:22           ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 23/26] elevate mnt writers for vfs_unlink() callers Dave Hansen
2007-06-23  7:51   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 24/26] do_rmdir(): elevate write count Dave Hansen
2007-06-23  7:51   ` Christoph Hellwig
2007-06-22 20:03 ` [PATCH 25/26] r/o bind mounts: scalable writer count Dave Hansen
2007-06-23 11:28   ` Miklos Szeredi
2007-06-23 11:31     ` Miklos Szeredi
2007-06-25 15:36     ` Dave Hansen
2007-06-25 19:09       ` Miklos Szeredi
2007-06-23 16:52   ` Andrew Morton
2007-06-25 15:47     ` Dave Hansen
2007-06-22 20:03 ` [PATCH 26/26] honor r/w changes at do_remount() time Dave Hansen
2007-06-23  7:51   ` Christoph Hellwig
2007-06-23 16:52 ` [PATCH 00/26] Mount writer count and read-only bind mounts Andrew Morton
2007-06-25 15:45   ` Dave Hansen
2007-06-30  9:57   ` Christoph Hellwig

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