From: Tejun Heo <tj@kernel.org>
To: gregkh@linuxfoundation.org
Cc: kay@vrfy.org, linux-kernel@vger.kernel.org,
ebiederm@xmission.com, bhelgaas@google.com,
Tejun Heo <tj@kernel.org>
Subject: [PATCH 11/41] sysfs, kernfs: prepare write path for kernfs
Date: Sat, 23 Nov 2013 17:21:56 -0500 [thread overview]
Message-ID: <1385245346-856-12-git-send-email-tj@kernel.org> (raw)
In-Reply-To: <1385245346-856-1-git-send-email-tj@kernel.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
rearranges write path so that the kernfs and sysfs parts are separate.
kernfs_file_write() handles all boilerplate work including buffer
management and locking and invokes sysfs_kf_write() or
sysfs_kf_bin_write() depending on the file type which deals with the
interaction with kobj store or bin_attribute write method.
While this patch changes the order of some operations, it shouldn't
change any visible behavior.
Signed-off-by: Tejun Heo <tj@kernel.org>
---
fs/sysfs/file.c | 103 +++++++++++++++++++++++++++-----------------------------
1 file changed, 50 insertions(+), 53 deletions(-)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index b695b8b..2f849e8 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -267,61 +267,50 @@ static ssize_t kernfs_file_read(struct file *file, char __user *user_buf,
return seq_read(file, user_buf, count, ppos);
}
-/**
- * flush_write_buffer - push buffer to kobject
- * @of: open file
- * @buf: data buffer for file
- * @off: file offset to write to
- * @count: number of bytes
- *
- * Get the correct pointers for the kobject and the attribute we're dealing
- * with, then call the store() method for it with @buf.
- */
-static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
- size_t count)
+/* kernfs write callback for regular sysfs files */
+static ssize_t sysfs_kf_write(struct sysfs_open_file *of, char *buf,
+ size_t count, loff_t pos)
{
+ const struct sysfs_ops *ops = sysfs_file_ops(of->sd);
struct kobject *kobj = of->sd->s_parent->priv;
- int rc = 0;
- /*
- * Need @of->sd for attr and ops, its parent for kobj. @of->mutex
- * nests outside active ref and is just to ensure that the ops
- * aren't called concurrently for the same open file.
- */
- mutex_lock(&of->mutex);
- if (!sysfs_get_active(of->sd)) {
- mutex_unlock(&of->mutex);
- return -ENODEV;
- }
+ if (!count)
+ return 0;
- if (sysfs_is_bin(of->sd)) {
- struct bin_attribute *battr = of->sd->priv;
+ return ops->store(kobj, of->sd->priv, buf, count);
+}
- rc = -EIO;
- if (battr->write)
- rc = battr->write(of->file, kobj, battr, buf, off,
- count);
- } else {
- const struct sysfs_ops *ops = sysfs_file_ops(of->sd);
+/* kernfs write callback for bin sysfs files */
+static ssize_t sysfs_kf_bin_write(struct sysfs_open_file *of, char *buf,
+ size_t count, loff_t pos)
+{
+ struct bin_attribute *battr = of->sd->priv;
+ struct kobject *kobj = of->sd->s_parent->priv;
+ loff_t size = file_inode(of->file)->i_size;
- rc = ops->store(kobj, of->sd->priv, buf, count);
+ if (size) {
+ if (size <= pos)
+ return 0;
+ count = min_t(ssize_t, count, size - pos);
}
+ if (!count)
+ return 0;
- sysfs_put_active(of->sd);
- mutex_unlock(&of->mutex);
+ if (!battr->write)
+ return -EIO;
- return rc;
+ return battr->write(of->file, kobj, battr, buf, pos, count);
}
/**
- * sysfs_write_file - write an attribute
+ * kernfs_file_write - kernfs vfs write callback
* @file: file pointer
* @user_buf: data to write
* @count: number of bytes
* @ppos: starting offset
*
- * Copy data in from userland and pass it to the matching
- * sysfs_ops->store() by invoking flush_write_buffer().
+ * Copy data in from userland and pass it to the matching kernfs write
+ * operation.
*
* There is no easy way for us to know if userspace is only doing a partial
* write, so we don't support them. We expect the entire buffer to come on
@@ -329,23 +318,13 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
* modify only the the value you're changing, then write entire buffer
* back.
*/
-static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf,
- size_t count, loff_t *ppos)
+static ssize_t kernfs_file_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
{
struct sysfs_open_file *of = sysfs_of(file);
ssize_t len = min_t(size_t, count, PAGE_SIZE);
- loff_t size = file_inode(file)->i_size;
char *buf;
- if (sysfs_is_bin(of->sd) && size) {
- if (size <= *ppos)
- return 0;
- len = min_t(ssize_t, len, size - *ppos);
- }
-
- if (!len)
- return 0;
-
buf = kmalloc(len + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
@@ -356,7 +335,25 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf,
}
buf[len] = '\0'; /* guarantee string termination */
- len = flush_write_buffer(of, buf, *ppos, len);
+ /*
+ * @of->mutex nests outside active ref and is just to ensure that
+ * the ops aren't called concurrently for the same open file.
+ */
+ mutex_lock(&of->mutex);
+ if (!sysfs_get_active(of->sd)) {
+ mutex_unlock(&of->mutex);
+ len = -ENODEV;
+ goto out_free;
+ }
+
+ if (sysfs_is_bin(of->sd))
+ len = sysfs_kf_bin_write(of, buf, len, *ppos);
+ else
+ len = sysfs_kf_write(of, buf, len, *ppos);
+
+ sysfs_put_active(of->sd);
+ mutex_unlock(&of->mutex);
+
if (len > 0)
*ppos += len;
out_free:
@@ -878,7 +875,7 @@ EXPORT_SYMBOL_GPL(sysfs_notify);
const struct file_operations sysfs_file_operations = {
.read = kernfs_file_read,
- .write = sysfs_write_file,
+ .write = kernfs_file_write,
.llseek = generic_file_llseek,
.open = sysfs_open_file,
.release = sysfs_release,
@@ -887,7 +884,7 @@ const struct file_operations sysfs_file_operations = {
const struct file_operations sysfs_bin_operations = {
.read = kernfs_file_read,
- .write = sysfs_write_file,
+ .write = kernfs_file_write,
.llseek = generic_file_llseek,
.mmap = sysfs_bin_mmap,
.open = sysfs_open_file,
--
1.8.4.2
next prev parent reply other threads:[~2013-11-23 22:32 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-23 22:21 [PATCHSET driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-23 22:21 ` [PATCH 01/41] sysfs: drop kobj_ns_type handling, take #2 Tejun Heo
2013-11-23 23:05 ` [PATCH v2 " Tejun Heo
2013-11-23 22:21 ` [PATCH 02/41] sysfs: make __sysfs_add_one() fail if the parent isn't a directory Tejun Heo
2013-11-23 22:21 ` [PATCH 03/41] sysfs, kernfs: add skeletons for kernfs Tejun Heo
2013-11-24 14:54 ` [PATCH REPOST " Tejun Heo
2013-11-23 22:21 ` [PATCH 04/41] sysfs, kernfs: introduce kernfs_remove[_by_name[_ns]]() Tejun Heo
2013-11-23 22:21 ` [PATCH 05/41] sysfs, kernfs: introduce kernfs_create_link() Tejun Heo
2013-11-23 22:21 ` [PATCH 06/41] sysfs, kernfs: introduce kernfs_rename[_ns]() Tejun Heo
2013-11-23 22:21 ` [PATCH 07/41] sysfs, kernfs: introduce kernfs_setattr() Tejun Heo
2013-11-23 22:21 ` [PATCH 08/41] sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv Tejun Heo
2013-11-23 22:21 ` [PATCH 09/41] sysfs, kernfs: introduce kernfs_create_dir[_ns]() Tejun Heo
2013-11-23 23:07 ` [PATCH v4 " Tejun Heo
2013-11-28 6:05 ` Greg KH
2013-11-28 19:54 ` [PATCHSET PARTIAL REPOST driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-28 19:54 ` [PATCH 01/34] sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv Tejun Heo
2013-11-28 19:54 ` [PATCH 02/34] sysfs, kernfs: introduce kernfs_create_dir[_ns]() Tejun Heo
2013-11-28 19:54 ` [PATCH 03/34] sysfs, kernfs: prepare read path for kernfs Tejun Heo
2013-11-28 19:54 ` [PATCH 04/34] sysfs, kernfs: prepare write " Tejun Heo
2013-11-28 19:54 ` [PATCH 05/34] sysfs, kernfs: prepare mmap " Tejun Heo
2013-11-28 19:54 ` [PATCH 06/34] sysfs, kernfs: prepare open, release, poll paths " Tejun Heo
2013-11-28 19:54 ` [PATCH 07/34] sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h Tejun Heo
2013-11-28 19:54 ` [PATCH 08/34] sysfs, kernfs: introduce kernfs_ops Tejun Heo
2013-11-28 19:54 ` [PATCH 09/34] sysfs, kernfs: add sysfs_dirent->s_attr.size Tejun Heo
2013-11-28 19:54 ` [PATCH 10/34] sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR Tejun Heo
2013-11-28 19:54 ` [PATCH 11/34] sysfs, kernfs: introduce kernfs_create_file[_ns]() Tejun Heo
2013-11-28 19:54 ` [PATCH 12/34] sysfs, kernfs: remove sysfs_add_one() Tejun Heo
2013-11-28 19:54 ` [PATCH 13/34] sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() Tejun Heo
2013-11-28 19:54 ` [PATCH 14/34] sysfs, kernfs: introduce kernfs_notify() Tejun Heo
2013-11-28 19:54 ` [PATCH 15/34] sysfs, kernfs: reorganize SYSFS_* constants Tejun Heo
2013-11-28 19:54 ` [PATCH 16/34] sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Tejun Heo
2013-11-28 19:54 ` [PATCH 17/34] sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() Tejun Heo
2013-11-28 19:54 ` [PATCH 18/34] sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.h Tejun Heo
2013-11-28 19:54 ` [PATCH 19/34] sysfs, kernfs: move inode code to fs/kernfs/inode.c Tejun Heo
2013-11-28 19:54 ` [PATCH 20/34] sysfs, kernfs: move dir core code to fs/kernfs/dir.c Tejun Heo
2013-11-28 19:54 ` [PATCH 21/34] sysfs, kernfs: move file core code to fs/kernfs/file.c Tejun Heo
2013-11-28 19:54 ` [PATCH 22/34] sysfs, kernfs: move symlink core code to fs/kernfs/symlink.c Tejun Heo
2013-11-28 19:54 ` [PATCH 23/34] sysfs, kernfs: drop unused params from sysfs_fill_super() Tejun Heo
2013-11-28 19:54 ` [PATCH 24/34] sysfs, kernfs: make sysfs_super_info->ns const Tejun Heo
2013-11-28 19:54 ` [PATCH 25/34] sysfs, kernfs: no need to kern_mount() sysfs from sysfs_init() Tejun Heo
2013-11-28 19:54 ` [PATCH 26/34] sysfs, kernfs: introduce sysfs_root_sd Tejun Heo
2013-11-28 19:54 ` [PATCH 27/34] sysfs, kernfs: implement kernfs_create/destroy_root() Tejun Heo
2013-11-28 19:54 ` [PATCH 28/34] sysfs, kernfs: make inode number ida per kernfs_root Tejun Heo
2013-11-28 19:54 ` [PATCH 29/34] sysfs, kernfs: make super_blocks bind to different kernfs_roots Tejun Heo
2013-11-28 19:54 ` [PATCH 30/34] sysfs, kernfs: prepare mount path for kernfs Tejun Heo
2013-11-28 19:54 ` [PATCH 31/34] sysfs, kernfs: move mount core code to fs/kernfs/mount.c Tejun Heo
2013-11-28 19:54 ` [PATCH 32/34] sysfs, kernfs: make sysfs_dirent definition public Tejun Heo
2013-11-29 22:18 ` Tejun Heo
2013-11-29 22:19 ` Tejun Heo
2013-11-28 19:54 ` [PATCH 33/34] sysfs, kernfs: implement kernfs_ns_enabled() Tejun Heo
2013-11-29 22:19 ` [PATCH v2 " Tejun Heo
2013-11-28 19:54 ` [PATCH 34/34] sysfs, kernfs: remove cross inclusions of internal headers Tejun Heo
2013-11-29 22:21 ` [PATCHSET PARTIAL REPOST driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-30 2:55 ` Greg KH
2013-11-30 13:05 ` Tejun Heo
2013-11-23 22:21 ` [PATCH 10/41] sysfs, kernfs: prepare read path for kernfs Tejun Heo
2013-11-23 22:21 ` Tejun Heo [this message]
2013-11-23 22:21 ` [PATCH 12/41] sysfs, kernfs: prepare mmap " Tejun Heo
2013-11-23 22:21 ` [PATCH 13/41] sysfs, kernfs: prepare open, release, poll paths " Tejun Heo
2013-11-23 22:21 ` [PATCH 14/41] sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h Tejun Heo
2013-11-23 22:22 ` [PATCH 15/41] sysfs, kernfs: introduce kernfs_ops Tejun Heo
2013-11-23 22:22 ` [PATCH 16/41] sysfs, kernfs: add sysfs_dirent->s_attr.size Tejun Heo
2013-11-23 22:22 ` [PATCH 17/41] sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR Tejun Heo
2013-11-23 22:22 ` [PATCH 18/41] sysfs, kernfs: introduce kernfs_create_file[_ns]() Tejun Heo
2013-11-23 22:22 ` [PATCH 19/41] sysfs, kernfs: remove sysfs_add_one() Tejun Heo
2013-11-23 22:22 ` [PATCH 20/41] sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() Tejun Heo
2013-11-23 22:22 ` [PATCH 21/41] sysfs, kernfs: introduce kernfs_notify() Tejun Heo
2013-11-23 22:22 ` [PATCH 22/41] sysfs, kernfs: reorganize SYSFS_* constants Tejun Heo
2013-11-23 22:22 ` [PATCH 23/41] sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Tejun Heo
2013-11-23 22:22 ` [PATCH 24/41] sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() Tejun Heo
2013-11-23 22:22 ` [PATCH 25/41] sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.h Tejun Heo
2013-11-23 22:22 ` [PATCH 26/41] sysfs, kernfs: move inode code to fs/kernfs/inode.c Tejun Heo
2013-11-23 22:22 ` [PATCH 27/41] sysfs, kernfs: move dir core code to fs/kernfs/dir.c Tejun Heo
2013-11-23 22:22 ` [PATCH 28/41] sysfs, kernfs: move file core code to fs/kernfs/file.c Tejun Heo
2013-11-23 22:22 ` [PATCH 29/41] sysfs, kernfs: move symlink core code to fs/kernfs/symlink.c Tejun Heo
2013-11-23 22:22 ` [PATCH 30/41] sysfs, kernfs: drop unused params from sysfs_fill_super() Tejun Heo
2013-11-23 22:22 ` [PATCH 31/41] sysfs, kernfs: make sysfs_super_info->ns const Tejun Heo
2013-11-23 22:22 ` [PATCH 32/41] sysfs, kernfs: no need to kern_mount() sysfs from sysfs_init() Tejun Heo
2013-11-23 22:22 ` [PATCH 33/41] sysfs, kernfs: introduce sysfs_root_sd Tejun Heo
2013-11-23 22:22 ` [PATCH 34/41] sysfs, kernfs: implement kernfs_create/destroy_root() Tejun Heo
2013-11-23 22:22 ` [PATCH 35/41] sysfs, kernfs: make inode number ida per kernfs_root Tejun Heo
2013-11-23 22:22 ` [PATCH 36/41] sysfs, kernfs: make super_blocks bind to different kernfs_roots Tejun Heo
2013-11-23 22:22 ` [PATCH 37/41] sysfs, kernfs: prepare mount path for kernfs Tejun Heo
2013-11-24 14:57 ` [PATCH REPOST " Tejun Heo
2013-11-23 22:22 ` [PATCH 38/41] sysfs, kernfs: move mount core code to fs/kernfs/mount.c Tejun Heo
2013-11-23 22:22 ` [PATCH 39/41] sysfs, kernfs: make sysfs_dirent definition public Tejun Heo
2013-11-23 22:22 ` [PATCH 40/41] sysfs, kernfs: implement kernfs_ns_enabled() Tejun Heo
2013-11-23 22:22 ` [PATCH 41/41] sysfs, kernfs: remove cross inclusions of internal headers Tejun Heo
2013-11-23 22:48 ` [PATCHSET driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-23 23:09 ` Tejun Heo
2013-11-24 9:16 ` Christoph Hellwig
2013-11-24 14:28 ` Tejun Heo
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