xattr: extract simple_xattr code from tmpfs
Extract in-memory xattr APIs from tmpfs. Will be used by cgroup. $ size vmlinux.o text data bss dec hex filename 4658782 880729 5195032 10734543 a3cbcf vmlinux.o $ size vmlinux.o text data bss dec hex filename 4658957 880729 5195032 10734718 a3cc7e vmlinux.o v7: - checkpatch warnings fixed - Implement the changes requested by Hugh Dickins: - make simple_xattrs_init and simple_xattrs_free inline - get rid of locking and list reinitialization in simple_xattrs_free, they're not needed v6: - no changes v5: - no changes v4: - move simple_xattrs_free() to fs/xattr.c v3: - in kmem_xattrs_free(), reinitialize the list - use simple_xattr_* prefix - introduce simple_xattr_add() to prevent direct list usage Original-patch-by: Li Zefan <lizefan@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Hillf Danton <dhillf@gmail.com> Cc: Lennart Poettering <lpoetter@redhat.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Aristeu Rozanski <aris@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Aristeu Rozanski
Tejun Heo
Родитель
fea7a08acb
Коммит
38f3865744
166
fs/xattr.c
166
fs/xattr.c
|
|
@ -791,3 +791,169 @@ EXPORT_SYMBOL(generic_getxattr);
|
|||
EXPORT_SYMBOL(generic_listxattr);
|
||||
EXPORT_SYMBOL(generic_setxattr);
|
||||
EXPORT_SYMBOL(generic_removexattr);
|
||||
|
||||
/*
|
||||
* Allocate new xattr and copy in the value; but leave the name to callers.
|
||||
*/
|
||||
struct simple_xattr *simple_xattr_alloc(const void *value, size_t size)
|
||||
{
|
||||
struct simple_xattr *new_xattr;
|
||||
size_t len;
|
||||
|
||||
/* wrap around? */
|
||||
len = sizeof(*new_xattr) + size;
|
||||
if (len <= sizeof(*new_xattr))
|
||||
return NULL;
|
||||
|
||||
new_xattr = kmalloc(len, GFP_KERNEL);
|
||||
if (!new_xattr)
|
||||
return NULL;
|
||||
|
||||
new_xattr->size = size;
|
||||
memcpy(new_xattr->value, value, size);
|
||||
return new_xattr;
|
||||
}
|
||||
|
||||
/*
|
||||
* xattr GET operation for in-memory/pseudo filesystems
|
||||
*/
|
||||
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
|
||||
void *buffer, size_t size)
|
||||
{
|
||||
struct simple_xattr *xattr;
|
||||
int ret = -ENODATA;
|
||||
|
||||
spin_lock(&xattrs->lock);
|
||||
list_for_each_entry(xattr, &xattrs->head, list) {
|
||||
if (strcmp(name, xattr->name))
|
||||
continue;
|
||||
|
||||
ret = xattr->size;
|
||||
if (buffer) {
|
||||
if (size < xattr->size)
|
||||
ret = -ERANGE;
|
||||
else
|
||||
memcpy(buffer, xattr->value, xattr->size);
|
||||
}
|
||||
break;
|
||||
}
|
||||
spin_unlock(&xattrs->lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int __simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
struct simple_xattr *xattr;
|
||||
struct simple_xattr *new_xattr = NULL;
|
||||
int err = 0;
|
||||
|
||||
/* value == NULL means remove */
|
||||
if (value) {
|
||||
new_xattr = simple_xattr_alloc(value, size);
|
||||
if (!new_xattr)
|
||||
return -ENOMEM;
|
||||
|
||||
new_xattr->name = kstrdup(name, GFP_KERNEL);
|
||||
if (!new_xattr->name) {
|
||||
kfree(new_xattr);
|
||||
return -ENOMEM;
|
||||
}
|
||||
}
|
||||
|
||||
spin_lock(&xattrs->lock);
|
||||
list_for_each_entry(xattr, &xattrs->head, list) {
|
||||
if (!strcmp(name, xattr->name)) {
|
||||
if (flags & XATTR_CREATE) {
|
||||
xattr = new_xattr;
|
||||
err = -EEXIST;
|
||||
} else if (new_xattr) {
|
||||
list_replace(&xattr->list, &new_xattr->list);
|
||||
} else {
|
||||
list_del(&xattr->list);
|
||||
}
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
if (flags & XATTR_REPLACE) {
|
||||
xattr = new_xattr;
|
||||
err = -ENODATA;
|
||||
} else {
|
||||
list_add(&new_xattr->list, &xattrs->head);
|
||||
xattr = NULL;
|
||||
}
|
||||
out:
|
||||
spin_unlock(&xattrs->lock);
|
||||
if (xattr) {
|
||||
kfree(xattr->name);
|
||||
kfree(xattr);
|
||||
}
|
||||
return err;
|
||||
|
||||
}
|
||||
|
||||
/*
|
||||
* xattr SET operation for in-memory/pseudo filesystems
|
||||
*/
|
||||
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
if (size == 0)
|
||||
value = ""; /* empty EA, do not remove */
|
||||
return __simple_xattr_set(xattrs, name, value, size, flags);
|
||||
}
|
||||
|
||||
/*
|
||||
* xattr REMOVE operation for in-memory/pseudo filesystems
|
||||
*/
|
||||
int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name)
|
||||
{
|
||||
return __simple_xattr_set(xattrs, name, NULL, 0, XATTR_REPLACE);
|
||||
}
|
||||
|
||||
static bool xattr_is_trusted(const char *name)
|
||||
{
|
||||
return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
|
||||
}
|
||||
|
||||
/*
|
||||
* xattr LIST operation for in-memory/pseudo filesystems
|
||||
*/
|
||||
ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
|
||||
size_t size)
|
||||
{
|
||||
bool trusted = capable(CAP_SYS_ADMIN);
|
||||
struct simple_xattr *xattr;
|
||||
size_t used = 0;
|
||||
|
||||
spin_lock(&xattrs->lock);
|
||||
list_for_each_entry(xattr, &xattrs->head, list) {
|
||||
size_t len;
|
||||
|
||||
/* skip "trusted." attributes for unprivileged callers */
|
||||
if (!trusted && xattr_is_trusted(xattr->name))
|
||||
continue;
|
||||
|
||||
len = strlen(xattr->name) + 1;
|
||||
used += len;
|
||||
if (buffer) {
|
||||
if (size < used) {
|
||||
used = -ERANGE;
|
||||
break;
|
||||
}
|
||||
memcpy(buffer, xattr->name, len);
|
||||
buffer += len;
|
||||
}
|
||||
}
|
||||
spin_unlock(&xattrs->lock);
|
||||
|
||||
return used;
|
||||
}
|
||||
|
||||
void simple_xattr_list_add(struct simple_xattrs *xattrs,
|
||||
struct simple_xattr *new_xattr)
|
||||
{
|
||||
spin_lock(&xattrs->lock);
|
||||
list_add(&new_xattr->list, &xattrs->head);
|
||||
spin_unlock(&xattrs->lock);
|
||||
}
|
||||
|
|
|
|||
|
|
@ -5,6 +5,7 @@
|
|||
#include <linux/mempolicy.h>
|
||||
#include <linux/pagemap.h>
|
||||
#include <linux/percpu_counter.h>
|
||||
#include <linux/xattr.h>
|
||||
|
||||
/* inode in-kernel data */
|
||||
|
||||
|
|
@ -18,7 +19,7 @@ struct shmem_inode_info {
|
|||
};
|
||||
struct shared_policy policy; /* NUMA memory alloc policy */
|
||||
struct list_head swaplist; /* chain of maybes on swap */
|
||||
struct list_head xattr_list; /* list of shmem_xattr */
|
||||
struct simple_xattrs xattrs; /* list of xattrs */
|
||||
struct inode vfs_inode;
|
||||
};
|
||||
|
||||
|
|
|
|||
|
|
@ -59,7 +59,9 @@
|
|||
|
||||
#ifdef __KERNEL__
|
||||
|
||||
#include <linux/slab.h>
|
||||
#include <linux/types.h>
|
||||
#include <linux/spinlock.h>
|
||||
|
||||
struct inode;
|
||||
struct dentry;
|
||||
|
|
@ -96,6 +98,52 @@ ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
|
|||
char **xattr_value, size_t size, gfp_t flags);
|
||||
int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
|
||||
const char *value, size_t size, gfp_t flags);
|
||||
|
||||
struct simple_xattrs {
|
||||
struct list_head head;
|
||||
spinlock_t lock;
|
||||
};
|
||||
|
||||
struct simple_xattr {
|
||||
struct list_head list;
|
||||
char *name;
|
||||
size_t size;
|
||||
char value[0];
|
||||
};
|
||||
|
||||
/*
|
||||
* initialize the simple_xattrs structure
|
||||
*/
|
||||
static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
|
||||
{
|
||||
INIT_LIST_HEAD(&xattrs->head);
|
||||
spin_lock_init(&xattrs->lock);
|
||||
}
|
||||
|
||||
/*
|
||||
* free all the xattrs
|
||||
*/
|
||||
static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
|
||||
{
|
||||
struct simple_xattr *xattr, *node;
|
||||
|
||||
list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
|
||||
kfree(xattr->name);
|
||||
kfree(xattr);
|
||||
}
|
||||
}
|
||||
|
||||
struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
|
||||
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
|
||||
void *buffer, size_t size);
|
||||
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
|
||||
const void *value, size_t size, int flags);
|
||||
int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
|
||||
ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
|
||||
size_t size);
|
||||
void simple_xattr_list_add(struct simple_xattrs *xattrs,
|
||||
struct simple_xattr *new_xattr);
|
||||
|
||||
#endif /* __KERNEL__ */
|
||||
|
||||
#endif /* _LINUX_XATTR_H */
|
||||
|
|
|
|||
171
mm/shmem.c
171
mm/shmem.c
|
|
@ -77,13 +77,6 @@ static struct vfsmount *shm_mnt;
|
|||
/* Symlink up to this size is kmalloc'ed instead of using a swappable page */
|
||||
#define SHORT_SYMLINK_LEN 128
|
||||
|
||||
struct shmem_xattr {
|
||||
struct list_head list; /* anchored by shmem_inode_info->xattr_list */
|
||||
char *name; /* xattr name */
|
||||
size_t size;
|
||||
char value[0];
|
||||
};
|
||||
|
||||
/*
|
||||
* shmem_fallocate and shmem_writepage communicate via inode->i_private
|
||||
* (with i_mutex making sure that it has only one user at a time):
|
||||
|
|
@ -636,7 +629,6 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
|
|||
static void shmem_evict_inode(struct inode *inode)
|
||||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(inode);
|
||||
struct shmem_xattr *xattr, *nxattr;
|
||||
|
||||
if (inode->i_mapping->a_ops == &shmem_aops) {
|
||||
shmem_unacct_size(info->flags, inode->i_size);
|
||||
|
|
@ -650,10 +642,7 @@ static void shmem_evict_inode(struct inode *inode)
|
|||
} else
|
||||
kfree(info->symlink);
|
||||
|
||||
list_for_each_entry_safe(xattr, nxattr, &info->xattr_list, list) {
|
||||
kfree(xattr->name);
|
||||
kfree(xattr);
|
||||
}
|
||||
simple_xattrs_free(&info->xattrs);
|
||||
BUG_ON(inode->i_blocks);
|
||||
shmem_free_inode(inode->i_sb);
|
||||
clear_inode(inode);
|
||||
|
|
@ -1377,7 +1366,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
|
|||
spin_lock_init(&info->lock);
|
||||
info->flags = flags & VM_NORESERVE;
|
||||
INIT_LIST_HEAD(&info->swaplist);
|
||||
INIT_LIST_HEAD(&info->xattr_list);
|
||||
simple_xattrs_init(&info->xattrs);
|
||||
cache_no_acl(inode);
|
||||
|
||||
switch (mode & S_IFMT) {
|
||||
|
|
@ -2059,28 +2048,6 @@ static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *co
|
|||
* filesystem level, though.
|
||||
*/
|
||||
|
||||
/*
|
||||
* Allocate new xattr and copy in the value; but leave the name to callers.
|
||||
*/
|
||||
static struct shmem_xattr *shmem_xattr_alloc(const void *value, size_t size)
|
||||
{
|
||||
struct shmem_xattr *new_xattr;
|
||||
size_t len;
|
||||
|
||||
/* wrap around? */
|
||||
len = sizeof(*new_xattr) + size;
|
||||
if (len <= sizeof(*new_xattr))
|
||||
return NULL;
|
||||
|
||||
new_xattr = kmalloc(len, GFP_KERNEL);
|
||||
if (!new_xattr)
|
||||
return NULL;
|
||||
|
||||
new_xattr->size = size;
|
||||
memcpy(new_xattr->value, value, size);
|
||||
return new_xattr;
|
||||
}
|
||||
|
||||
/*
|
||||
* Callback for security_inode_init_security() for acquiring xattrs.
|
||||
*/
|
||||
|
|
@ -2090,11 +2057,11 @@ static int shmem_initxattrs(struct inode *inode,
|
|||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(inode);
|
||||
const struct xattr *xattr;
|
||||
struct shmem_xattr *new_xattr;
|
||||
struct simple_xattr *new_xattr;
|
||||
size_t len;
|
||||
|
||||
for (xattr = xattr_array; xattr->name != NULL; xattr++) {
|
||||
new_xattr = shmem_xattr_alloc(xattr->value, xattr->value_len);
|
||||
new_xattr = simple_xattr_alloc(xattr->value, xattr->value_len);
|
||||
if (!new_xattr)
|
||||
return -ENOMEM;
|
||||
|
||||
|
|
@ -2111,91 +2078,12 @@ static int shmem_initxattrs(struct inode *inode,
|
|||
memcpy(new_xattr->name + XATTR_SECURITY_PREFIX_LEN,
|
||||
xattr->name, len);
|
||||
|
||||
spin_lock(&info->lock);
|
||||
list_add(&new_xattr->list, &info->xattr_list);
|
||||
spin_unlock(&info->lock);
|
||||
simple_xattr_list_add(&info->xattrs, new_xattr);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int shmem_xattr_get(struct dentry *dentry, const char *name,
|
||||
void *buffer, size_t size)
|
||||
{
|
||||
struct shmem_inode_info *info;
|
||||
struct shmem_xattr *xattr;
|
||||
int ret = -ENODATA;
|
||||
|
||||
info = SHMEM_I(dentry->d_inode);
|
||||
|
||||
spin_lock(&info->lock);
|
||||
list_for_each_entry(xattr, &info->xattr_list, list) {
|
||||
if (strcmp(name, xattr->name))
|
||||
continue;
|
||||
|
||||
ret = xattr->size;
|
||||
if (buffer) {
|
||||
if (size < xattr->size)
|
||||
ret = -ERANGE;
|
||||
else
|
||||
memcpy(buffer, xattr->value, xattr->size);
|
||||
}
|
||||
break;
|
||||
}
|
||||
spin_unlock(&info->lock);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int shmem_xattr_set(struct inode *inode, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(inode);
|
||||
struct shmem_xattr *xattr;
|
||||
struct shmem_xattr *new_xattr = NULL;
|
||||
int err = 0;
|
||||
|
||||
/* value == NULL means remove */
|
||||
if (value) {
|
||||
new_xattr = shmem_xattr_alloc(value, size);
|
||||
if (!new_xattr)
|
||||
return -ENOMEM;
|
||||
|
||||
new_xattr->name = kstrdup(name, GFP_KERNEL);
|
||||
if (!new_xattr->name) {
|
||||
kfree(new_xattr);
|
||||
return -ENOMEM;
|
||||
}
|
||||
}
|
||||
|
||||
spin_lock(&info->lock);
|
||||
list_for_each_entry(xattr, &info->xattr_list, list) {
|
||||
if (!strcmp(name, xattr->name)) {
|
||||
if (flags & XATTR_CREATE) {
|
||||
xattr = new_xattr;
|
||||
err = -EEXIST;
|
||||
} else if (new_xattr) {
|
||||
list_replace(&xattr->list, &new_xattr->list);
|
||||
} else {
|
||||
list_del(&xattr->list);
|
||||
}
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
if (flags & XATTR_REPLACE) {
|
||||
xattr = new_xattr;
|
||||
err = -ENODATA;
|
||||
} else {
|
||||
list_add(&new_xattr->list, &info->xattr_list);
|
||||
xattr = NULL;
|
||||
}
|
||||
out:
|
||||
spin_unlock(&info->lock);
|
||||
if (xattr)
|
||||
kfree(xattr->name);
|
||||
kfree(xattr);
|
||||
return err;
|
||||
}
|
||||
|
||||
static const struct xattr_handler *shmem_xattr_handlers[] = {
|
||||
#ifdef CONFIG_TMPFS_POSIX_ACL
|
||||
&generic_acl_access_handler,
|
||||
|
|
@ -2226,6 +2114,7 @@ static int shmem_xattr_validate(const char *name)
|
|||
static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
|
||||
void *buffer, size_t size)
|
||||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
|
||||
int err;
|
||||
|
||||
/*
|
||||
|
|
@ -2240,12 +2129,13 @@ static ssize_t shmem_getxattr(struct dentry *dentry, const char *name,
|
|||
if (err)
|
||||
return err;
|
||||
|
||||
return shmem_xattr_get(dentry, name, buffer, size);
|
||||
return simple_xattr_get(&info->xattrs, name, buffer, size);
|
||||
}
|
||||
|
||||
static int shmem_setxattr(struct dentry *dentry, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
|
||||
int err;
|
||||
|
||||
/*
|
||||
|
|
@ -2260,15 +2150,12 @@ static int shmem_setxattr(struct dentry *dentry, const char *name,
|
|||
if (err)
|
||||
return err;
|
||||
|
||||
if (size == 0)
|
||||
value = ""; /* empty EA, do not remove */
|
||||
|
||||
return shmem_xattr_set(dentry->d_inode, name, value, size, flags);
|
||||
|
||||
return simple_xattr_set(&info->xattrs, name, value, size, flags);
|
||||
}
|
||||
|
||||
static int shmem_removexattr(struct dentry *dentry, const char *name)
|
||||
{
|
||||
struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
|
||||
int err;
|
||||
|
||||
/*
|
||||
|
|
@ -2283,45 +2170,13 @@ static int shmem_removexattr(struct dentry *dentry, const char *name)
|
|||
if (err)
|
||||
return err;
|
||||
|
||||
return shmem_xattr_set(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
|
||||
}
|
||||
|
||||
static bool xattr_is_trusted(const char *name)
|
||||
{
|
||||
return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
|
||||
return simple_xattr_remove(&info->xattrs, name);
|
||||
}
|
||||
|
||||
static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
|
||||
{
|
||||
bool trusted = capable(CAP_SYS_ADMIN);
|
||||
struct shmem_xattr *xattr;
|
||||
struct shmem_inode_info *info;
|
||||
size_t used = 0;
|
||||
|
||||
info = SHMEM_I(dentry->d_inode);
|
||||
|
||||
spin_lock(&info->lock);
|
||||
list_for_each_entry(xattr, &info->xattr_list, list) {
|
||||
size_t len;
|
||||
|
||||
/* skip "trusted." attributes for unprivileged callers */
|
||||
if (!trusted && xattr_is_trusted(xattr->name))
|
||||
continue;
|
||||
|
||||
len = strlen(xattr->name) + 1;
|
||||
used += len;
|
||||
if (buffer) {
|
||||
if (size < used) {
|
||||
used = -ERANGE;
|
||||
break;
|
||||
}
|
||||
memcpy(buffer, xattr->name, len);
|
||||
buffer += len;
|
||||
}
|
||||
}
|
||||
spin_unlock(&info->lock);
|
||||
|
||||
return used;
|
||||
struct shmem_inode_info *info = SHMEM_I(dentry->d_inode);
|
||||
return simple_xattr_list(&info->xattrs, buffer, size);
|
||||
}
|
||||
#endif /* CONFIG_TMPFS_XATTR */
|
||||
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче