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AgeCommit message (Expand)Author
2012-07-23switch dentry_open() to struct path, make it grab references itselfAl Viro
2012-07-14don't pass nameidata * to vfs_create()Al Viro
2012-07-14don't pass nameidata to ->create()Al Viro
2012-06-07ipc: shm: restore MADV_REMOVE functionality on shared memory segmentsWill Deacon
2012-06-01Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vir...Linus Torvalds
2012-06-01switch aio and shm to do_mmap_pgoff(), make do_mmap() staticAl Viro
2012-06-01take security_mmap_file() outside of ->mmap_semAl Viro
2012-05-31ipc/mqueue: add rbtree node caching supportDoug Ledford
2012-05-31ipc/mqueue: strengthen checks on mqueue creationDoug Ledford
2012-05-31ipc/mqueue: correct mq_attr_ok testDoug Ledford
2012-05-31ipc/mqueue: improve performance of send/recvDoug Ledford
2012-05-31mqueue: separate mqueue default value from maximum valueKOSAKI Motohiro
2012-05-31mqueue: don't use kmalloc with KMALLOC_MAX_SIZEKOSAKI Motohiro
2012-05-31ipc/mqueue: update maximums for the mqueue subsystemDoug Ledford
2012-05-31ipc/mqueue: enforce hard limitsDoug Ledford
2012-05-31ipc/mqueue: switch back to using non-max values on createDoug Ledford
2012-05-31ipc/mqueue: cleanup definition names and locationsDoug Ledford
2012-05-28Merge tag 'writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linuxLinus Torvalds
2012-05-06vfs: Rename end_writeback() to clear_inode()Jan Kara
2012-05-03userns: Replace user_ns_map_uid and user_ns_map_gid with from_kuid and from_kgidEric W. Biederman
2012-04-07mqueue: Explicitly capture the user namespace to send the notification to.Eric W. Biederman
2012-04-07userns: Use cred->user_ns instead of cred->user->user_nsEric W. Biederman
2012-03-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tileLinus Torvalds
2012-03-22Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
2012-03-21hugetlbfs: fix alignment of huge page requestsSteven Truelove
2012-03-21Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vir...Linus Torvalds
2012-03-20switch open-coded instances of d_make_root() to new helperAl Viro
2012-03-15[PATCH v3] ipc: provide generic compat versions of IPC syscallsChris Metcalf
2012-02-14security: trim security.hAl Viro
2012-01-23SHM_UNLOCK: fix Unevictable pages stranded after swapHugh Dickins
2012-01-23SHM_UNLOCK: fix long unpreemptible sectionHugh Dickins
2012-01-23ipc/mqueue: simplify reading msgqueue limitDavidlohr Bueso
2012-01-10user namespace: make signal.c respect user namespacesSerge E. Hallyn
2012-01-03switch mq_open() to umode_tAl Viro
2012-01-03mqueue: propagate umode_tAl Viro
2012-01-03switch ->create() to umode_tAl Viro
2012-01-03vfs: fix the stupidity with i_dentry in inode destructorsAl Viro
2011-12-09... and the same kind of leak for mqueueAl Viro
2011-11-02ipc/sem.c: remove private structures from public header fileManfred Spraul
2011-11-02ipc/sem.c: handle spurious wakeupsManfred Spraul
2011-11-02ipc/sem.c: fix return code race with semop vs. semop +semctl(IPC_RMID)Manfred Spraul
2011-10-31ipc/mqueue.c: fix wrong use of schedule_hrtimeout_range_clock()Wanlong Gao
2011-08-04Do 'shm_init_ns()' in an early pure_initcallLinus Torvalds
2011-08-03shm: optimize exit_shm()Vasiliy Kulikov
2011-08-03shm: fix wrong testsVasiliy Kulikov
2011-07-30shm: optimize locking and ipc_namespace gettingVasiliy Kulikov
2011-07-30shm: handle separate PID namespaces caseVasiliy Kulikov
2011-07-26ipc: introduce shm_rmid_forced sysctlVasiliy Kulikov
2011-07-26ipc/mqueue.c: fix mq_open() return valueJiri Slaby
2011-07-26ipc/mqueue.c: refactor failure handlingJiri Slaby
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/*
 * fs/sysfs/file.c - sysfs regular (text) file implementation
 *
 * Copyright (c) 2001-3 Patrick Mochel
 * Copyright (c) 2007 SUSE Linux Products GmbH
 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
 *
 * This file is released under the GPLv2.
 *
 * Please see Documentation/filesystems/sysfs.txt for more information.
 */

#include <linux/module.h>
#include <linux/kobject.h>
#include <linux/kallsyms.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>

#include "sysfs.h"
#include "../kernfs/kernfs-internal.h"

/*
 * Determine ktype->sysfs_ops for the given kernfs_node.  This function
 * must be called while holding an active reference.
 */
static const struct sysfs_ops *sysfs_file_ops(struct kernfs_node *kn)
{
	struct kobject *kobj = kn->parent->priv;

	if (kn->flags & KERNFS_LOCKDEP)
		lockdep_assert_held(kn);
	return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
}

/*
 * Reads on sysfs are handled through seq_file, which takes care of hairy
 * details like buffering and seeking.  The following function pipes
 * sysfs_ops->show() result through seq_file.
 */
static int sysfs_kf_seq_show(struct seq_file *sf, void *v)
{
	struct kernfs_open_file *of = sf->private;
	struct kobject *kobj = of->kn->parent->priv;
	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
	ssize_t count;
	char *buf;

	/* acquire buffer and ensure that it's >= PAGE_SIZE and clear */
	count = seq_get_buf(sf, &buf);
	if (count < PAGE_SIZE) {
		seq_commit(sf, -1);
		return 0;
	}
	memset(buf, 0, PAGE_SIZE);

	/*
	 * Invoke show().  Control may reach here via seq file lseek even
	 * if @ops->show() isn't implemented.
	 */
	if (ops->show) {
		count = ops->show(kobj, of->kn->priv, buf);
		if (count < 0)
			return count;
	}

	/*
	 * The code works fine with PAGE_SIZE return but it's likely to
	 * indicate truncated result or overflow in normal use cases.
	 */
	if (count >= (ssize_t)PAGE_SIZE) {
		print_symbol("fill_read_buffer: %s returned bad count\n",
			(unsigned long)ops->show);
		/* Try to struggle along */
		count = PAGE_SIZE - 1;
	}
	seq_commit(sf, count);
	return 0;
}

static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
				 size_t count, loff_t pos)
{
	struct bin_attribute *battr = of->kn->priv;
	struct kobject *kobj = of->kn->parent->priv;
	loff_t size = file_inode(of->file)->i_size;

	if (!count)
		return 0;

	if (size) {
		if (pos >= size)
			return 0;
		if (pos + count > size)
			count = size - pos;
	}

	if (!battr->read)
		return -EIO;

	return battr->read(of->file, kobj, battr, buf, pos, count);
}

/* kernfs read callback for regular sysfs files with pre-alloc */
static ssize_t sysfs_kf_read(struct kernfs_open_file *of, char *buf,
			     size_t count, loff_t pos)
{
	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
	struct kobject *kobj = of->kn->parent->priv;
	ssize_t len;

	/*
	 * If buf != of->prealloc_buf, we don't know how
	 * large it is, so cannot safely pass it to ->show
	 */
	if (WARN_ON_ONCE(buf != of->prealloc_buf))
		return 0;
	len = ops->show(kobj, of->kn->priv, buf);
	if (len < 0)
		return len;
	if (pos) {
		if (len <= pos)
			return 0;
		len -= pos;
		memmove(buf, buf + pos, len);
	}
	return min_t(ssize_t, count, len);
}

/* kernfs write callback for regular sysfs files */
static ssize_t sysfs_kf_write(struct kernfs_open_file *of, char *buf,
			      size_t count, loff_t pos)
{
	const struct sysfs_ops *ops = sysfs_file_ops(of->kn);
	struct kobject *kobj = of->kn->parent->priv;

	if (!count)
		return 0;

	return ops->store(kobj, of->kn->priv, buf, count);
}

/* kernfs write callback for bin sysfs files */
static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
				  size_t count, loff_t pos)
{
	struct bin_attribute *battr = of->kn->priv;
	struct kobject *kobj = of->kn->parent->priv;
	loff_t size = file_inode(of->file)->i_size;

	if (size) {
		if (size <= pos)
			return -EFBIG;
		count = min_t(ssize_t, count, size - pos);
	}
	if (!count)
		return 0;

	if (!battr->write)
		return -EIO;

	return battr->write(of->file, kobj, battr, buf, pos, count);
}

static int sysfs_kf_bin_mmap(struct kernfs_open_file *of,
			     struct vm_area_struct *vma)
{
	struct bin_attribute *battr = of->kn->priv;
	struct kobject *kobj = of->kn->parent->priv;

	return battr->mmap(of->file, kobj, battr, vma);
}

void sysfs_notify(struct kobject *kobj, const char *dir, const char *attr)
{
	struct kernfs_node *kn = kobj->sd, *tmp;

	if (kn && dir)
		kn = kernfs_find_and_get(kn, dir);
	else
		kernfs_get(kn);

	if (kn && attr) {
		tmp = kernfs_find_and_get(kn, attr);
		kernfs_put(kn);
		kn = tmp;
	}

	if (kn) {
		kernfs_notify(kn);
		kernfs_put(kn);
	}
}
EXPORT_SYMBOL_GPL(sysfs_notify);

static const struct kernfs_ops sysfs_file_kfops_empty = {
};

static const struct kernfs_ops sysfs_file_kfops_ro = {
	.seq_show	= sysfs_kf_seq_show,
};

static const struct kernfs_ops sysfs_file_kfops_wo = {
	.write		= sysfs_kf_write,
};

static const struct kernfs_ops sysfs_file_kfops_rw = {
	.seq_show	= sysfs_kf_seq_show,
	.write		= sysfs_kf_write,
};

static const struct kernfs_ops sysfs_prealloc_kfops_ro = {
	.read		= sysfs_kf_read,
	.prealloc	= true,
};

static const struct kernfs_ops sysfs_prealloc_kfops_wo = {
	.write		= sysfs_kf_write,
	.prealloc	= true,
};

static const struct kernfs_ops sysfs_prealloc_kfops_rw = {
	.read		= sysfs_kf_read,
	.write		= sysfs_kf_write,
	.prealloc	= true,
};

static const struct kernfs_ops sysfs_bin_kfops_ro = {
	.read		= sysfs_kf_bin_read,
};

static const struct kernfs_ops sysfs_bin_kfops_wo = {
	.write		=