155716d26SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2b8441ed2STejun Heo /*
3b8441ed2STejun Heo * fs/kernfs/inode.c - kernfs inode implementation
4b8441ed2STejun Heo *
5b8441ed2STejun Heo * Copyright (c) 2001-3 Patrick Mochel
6b8441ed2STejun Heo * Copyright (c) 2007 SUSE Linux Products GmbH
7b8441ed2STejun Heo * Copyright (c) 2007, 2013 Tejun Heo <tj@kernel.org>
8b8441ed2STejun Heo */
9ffed24e2STejun Heo
10ffed24e2STejun Heo #include <linux/pagemap.h>
11ffed24e2STejun Heo #include <linux/backing-dev.h>
12ffed24e2STejun Heo #include <linux/capability.h>
13ffed24e2STejun Heo #include <linux/errno.h>
14ffed24e2STejun Heo #include <linux/slab.h>
15ffed24e2STejun Heo #include <linux/xattr.h>
16ffed24e2STejun Heo #include <linux/security.h>
17ffed24e2STejun Heo
18ffed24e2STejun Heo #include "kernfs-internal.h"
19ffed24e2STejun Heo
20a797bfc3STejun Heo static const struct inode_operations kernfs_iops = {
21c637b8acSTejun Heo .permission = kernfs_iop_permission,
22c637b8acSTejun Heo .setattr = kernfs_iop_setattr,
23c637b8acSTejun Heo .getattr = kernfs_iop_getattr,
24c637b8acSTejun Heo .listxattr = kernfs_iop_listxattr,
25ffed24e2STejun Heo };
26ffed24e2STejun Heo
__kernfs_iattrs(struct kernfs_node * kn,int alloc)27d0c9c153SOndrej Mosnacek static struct kernfs_iattrs *__kernfs_iattrs(struct kernfs_node *kn, int alloc)
28ffed24e2STejun Heo {
294afddd60STejun Heo static DEFINE_MUTEX(iattr_mutex);
304afddd60STejun Heo struct kernfs_iattrs *ret;
31ffed24e2STejun Heo
324afddd60STejun Heo mutex_lock(&iattr_mutex);
334afddd60STejun Heo
34d0c9c153SOndrej Mosnacek if (kn->iattr || !alloc)
354afddd60STejun Heo goto out_unlock;
369a8049afSTejun Heo
3726e28d68SAyush Mittal kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);
38adc5e8b5STejun Heo if (!kn->iattr)
394afddd60STejun Heo goto out_unlock;
40ffed24e2STejun Heo
41ffed24e2STejun Heo /* assign default attributes */
4205895219SOndrej Mosnacek kn->iattr->ia_uid = GLOBAL_ROOT_UID;
4305895219SOndrej Mosnacek kn->iattr->ia_gid = GLOBAL_ROOT_GID;
443a3a5fecSDeepa Dinamani
4505895219SOndrej Mosnacek ktime_get_real_ts64(&kn->iattr->ia_atime);
4605895219SOndrej Mosnacek kn->iattr->ia_mtime = kn->iattr->ia_atime;
4705895219SOndrej Mosnacek kn->iattr->ia_ctime = kn->iattr->ia_atime;
48ffed24e2STejun Heo
49adc5e8b5STejun Heo simple_xattrs_init(&kn->iattr->xattrs);
500c47383bSDaniel Xu atomic_set(&kn->iattr->nr_user_xattrs, 0);
510c47383bSDaniel Xu atomic_set(&kn->iattr->user_xattr_size, 0);
524afddd60STejun Heo out_unlock:
534afddd60STejun Heo ret = kn->iattr;
544afddd60STejun Heo mutex_unlock(&iattr_mutex);
554afddd60STejun Heo return ret;
56ffed24e2STejun Heo }
57ffed24e2STejun Heo
kernfs_iattrs(struct kernfs_node * kn)58d0c9c153SOndrej Mosnacek static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
59d0c9c153SOndrej Mosnacek {
60d0c9c153SOndrej Mosnacek return __kernfs_iattrs(kn, 1);
61d0c9c153SOndrej Mosnacek }
62d0c9c153SOndrej Mosnacek
kernfs_iattrs_noalloc(struct kernfs_node * kn)63d0c9c153SOndrej Mosnacek static struct kernfs_iattrs *kernfs_iattrs_noalloc(struct kernfs_node *kn)
64d0c9c153SOndrej Mosnacek {
65d0c9c153SOndrej Mosnacek return __kernfs_iattrs(kn, 0);
66d0c9c153SOndrej Mosnacek }
67d0c9c153SOndrej Mosnacek
__kernfs_setattr(struct kernfs_node * kn,const struct iattr * iattr)68488dee96SDmitry Torokhov int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
69ffed24e2STejun Heo {
70c525aaddSTejun Heo struct kernfs_iattrs *attrs;
71ffed24e2STejun Heo unsigned int ia_valid = iattr->ia_valid;
72ffed24e2STejun Heo
73c525aaddSTejun Heo attrs = kernfs_iattrs(kn);
749a8049afSTejun Heo if (!attrs)
75ffed24e2STejun Heo return -ENOMEM;
769a8049afSTejun Heo
77ffed24e2STejun Heo if (ia_valid & ATTR_UID)
7805895219SOndrej Mosnacek attrs->ia_uid = iattr->ia_uid;
79ffed24e2STejun Heo if (ia_valid & ATTR_GID)
8005895219SOndrej Mosnacek attrs->ia_gid = iattr->ia_gid;
81ffed24e2STejun Heo if (ia_valid & ATTR_ATIME)
8205895219SOndrej Mosnacek attrs->ia_atime = iattr->ia_atime;
83ffed24e2STejun Heo if (ia_valid & ATTR_MTIME)
8405895219SOndrej Mosnacek attrs->ia_mtime = iattr->ia_mtime;
85ffed24e2STejun Heo if (ia_valid & ATTR_CTIME)
8605895219SOndrej Mosnacek attrs->ia_ctime = iattr->ia_ctime;
8705895219SOndrej Mosnacek if (ia_valid & ATTR_MODE)
8805895219SOndrej Mosnacek kn->mode = iattr->ia_mode;
89ffed24e2STejun Heo return 0;
90ffed24e2STejun Heo }
91ffed24e2STejun Heo
92ffed24e2STejun Heo /**
93ffed24e2STejun Heo * kernfs_setattr - set iattr on a node
94324a56e1STejun Heo * @kn: target node
95ffed24e2STejun Heo * @iattr: iattr to set
96ffed24e2STejun Heo *
9724b3e3ddSRandy Dunlap * Return: %0 on success, -errno on failure.
98ffed24e2STejun Heo */
kernfs_setattr(struct kernfs_node * kn,const struct iattr * iattr)99324a56e1STejun Heo int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
100ffed24e2STejun Heo {
101ffed24e2STejun Heo int ret;
102393c3714SMinchan Kim struct kernfs_root *root = kernfs_root(kn);
103ffed24e2STejun Heo
1049caf6961SImran Khan down_write(&root->kernfs_iattr_rwsem);
105324a56e1STejun Heo ret = __kernfs_setattr(kn, iattr);
1069caf6961SImran Khan up_write(&root->kernfs_iattr_rwsem);
107ffed24e2STejun Heo return ret;
108ffed24e2STejun Heo }
109ffed24e2STejun Heo
kernfs_iop_setattr(struct mnt_idmap * idmap,struct dentry * dentry,struct iattr * iattr)110c1632a0fSChristian Brauner int kernfs_iop_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
111549c7297SChristian Brauner struct iattr *iattr)
112ffed24e2STejun Heo {
1132b0143b5SDavid Howells struct inode *inode = d_inode(dentry);
114319ba91dSShaohua Li struct kernfs_node *kn = inode->i_private;
115393c3714SMinchan Kim struct kernfs_root *root;
116ffed24e2STejun Heo int error;
117ffed24e2STejun Heo
118324a56e1STejun Heo if (!kn)
119ffed24e2STejun Heo return -EINVAL;
120ffed24e2STejun Heo
121393c3714SMinchan Kim root = kernfs_root(kn);
1229caf6961SImran Khan down_write(&root->kernfs_iattr_rwsem);
123c1632a0fSChristian Brauner error = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
124ffed24e2STejun Heo if (error)
125ffed24e2STejun Heo goto out;
126ffed24e2STejun Heo
127324a56e1STejun Heo error = __kernfs_setattr(kn, iattr);
128ffed24e2STejun Heo if (error)
129ffed24e2STejun Heo goto out;
130ffed24e2STejun Heo
131ffed24e2STejun Heo /* this ignores size changes */
132c1632a0fSChristian Brauner setattr_copy(&nop_mnt_idmap, inode, iattr);
133ffed24e2STejun Heo
134ffed24e2STejun Heo out:
1359caf6961SImran Khan up_write(&root->kernfs_iattr_rwsem);
136ffed24e2STejun Heo return error;
137ffed24e2STejun Heo }
138ffed24e2STejun Heo
kernfs_iop_listxattr(struct dentry * dentry,char * buf,size_t size)139c637b8acSTejun Heo ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
1402322392bSTejun Heo {
141319ba91dSShaohua Li struct kernfs_node *kn = kernfs_dentry_node(dentry);
142c525aaddSTejun Heo struct kernfs_iattrs *attrs;
1432322392bSTejun Heo
144c525aaddSTejun Heo attrs = kernfs_iattrs(kn);
1452322392bSTejun Heo if (!attrs)
1462322392bSTejun Heo return -ENOMEM;
1472322392bSTejun Heo
148786534b9SAndreas Gruenbacher return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size);
149ffed24e2STejun Heo }
150ffed24e2STejun Heo
set_default_inode_attr(struct inode * inode,umode_t mode)151ffed24e2STejun Heo static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
152ffed24e2STejun Heo {
153ffed24e2STejun Heo inode->i_mode = mode;
1543a3a5fecSDeepa Dinamani inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode);
155c2050a45SDeepa Dinamani }
156ffed24e2STejun Heo
set_inode_attr(struct inode * inode,struct kernfs_iattrs * attrs)157ffed24e2STejun Heo static inline void set_inode_attr(struct inode *inode,
15805895219SOndrej Mosnacek struct kernfs_iattrs *attrs)
15905895219SOndrej Mosnacek {
160ffed24e2STejun Heo inode->i_uid = attrs->ia_uid;
16105895219SOndrej Mosnacek inode->i_gid = attrs->ia_gid;
16205895219SOndrej Mosnacek inode->i_atime = attrs->ia_atime;
163f0f3588fSAl Viro inode->i_mtime = attrs->ia_mtime;
164f0f3588fSAl Viro inode_set_ctime_to_ts(inode, attrs->ia_ctime);
165f0f3588fSAl Viro }
166ffed24e2STejun Heo
kernfs_refresh_inode(struct kernfs_node * kn,struct inode * inode)167ffed24e2STejun Heo static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
168c637b8acSTejun Heo {
169ffed24e2STejun Heo struct kernfs_iattrs *attrs = kn->iattr;
170c525aaddSTejun Heo
171ffed24e2STejun Heo inode->i_mode = kn->mode;
172adc5e8b5STejun Heo if (attrs)
1730ac6075aSOndrej Mosnacek /*
174324a56e1STejun Heo * kernfs_node has non-default attributes get them from
175324a56e1STejun Heo * persistent copy in kernfs_node.
176324a56e1STejun Heo */
177ffed24e2STejun Heo set_inode_attr(inode, attrs);
17805895219SOndrej Mosnacek
179ffed24e2STejun Heo if (kernfs_type(kn) == KERNFS_DIR)
180df23fc39STejun Heo set_nlink(inode, kn->dir.subdirs + 2);
181adc5e8b5STejun Heo }
182ffed24e2STejun Heo
kernfs_iop_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int query_flags)183ffed24e2STejun Heo int kernfs_iop_getattr(struct mnt_idmap *idmap,
184b74d24f7SChristian Brauner const struct path *path, struct kstat *stat,
185549c7297SChristian Brauner u32 request_mask, unsigned int query_flags)
186a528d35eSDavid Howells {
187ffed24e2STejun Heo struct inode *inode = d_inode(path->dentry);
188a528d35eSDavid Howells struct kernfs_node *kn = inode->i_private;
189319ba91dSShaohua Li struct kernfs_root *root = kernfs_root(kn);
190393c3714SMinchan Kim
191ffed24e2STejun Heo down_read(&root->kernfs_iattr_rwsem);
1929caf6961SImran Khan kernfs_refresh_inode(kn, inode);
193c637b8acSTejun Heo generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
194b74d24f7SChristian Brauner up_read(&root->kernfs_iattr_rwsem);
1959caf6961SImran Khan
19647b5c64dSIan Kent return 0;
197ffed24e2STejun Heo }
198ffed24e2STejun Heo
kernfs_init_inode(struct kernfs_node * kn,struct inode * inode)199ffed24e2STejun Heo static void kernfs_init_inode(struct kernfs_node *kn, struct inode *inode)
200c637b8acSTejun Heo {
201ffed24e2STejun Heo kernfs_get(kn);
202324a56e1STejun Heo inode->i_private = kn;
203324a56e1STejun Heo inode->i_mapping->a_ops = &ram_aops;
204c1e3dbe9SChristoph Hellwig inode->i_op = &kernfs_iops;
205a797bfc3STejun Heo inode->i_generation = kernfs_gen(kn);
20667c0496eSTejun Heo
207ffed24e2STejun Heo set_default_inode_attr(inode, kn->mode);
208adc5e8b5STejun Heo kernfs_refresh_inode(kn, inode);
209c637b8acSTejun Heo
210ffed24e2STejun Heo /* initialize inode according to type */
211ffed24e2STejun Heo switch (kernfs_type(kn)) {
212df23fc39STejun Heo case KERNFS_DIR:
213df23fc39STejun Heo inode->i_op = &kernfs_dir_iops;
214a797bfc3STejun Heo inode->i_fop = &kernfs_dir_fops;
215a797bfc3STejun Heo if (kn->flags & KERNFS_EMPTY_DIR)
216ea015218SEric W. Biederman make_empty_dir_inode(inode);
217ea015218SEric W. Biederman break;
218ffed24e2STejun Heo case KERNFS_FILE:
219df23fc39STejun Heo inode->i_size = kn->attr.size;
220adc5e8b5STejun Heo inode->i_fop = &kernfs_file_fops;
221a797bfc3STejun Heo break;
222ffed24e2STejun Heo case KERNFS_LINK:
223df23fc39STejun Heo inode->i_op = &kernfs_symlink_iops;
224a797bfc3STejun Heo break;
225ffed24e2STejun Heo default:
226ffed24e2STejun Heo BUG();
227ffed24e2STejun Heo }
228ffed24e2STejun Heo
229ffed24e2STejun Heo unlock_new_inode(inode);
230ffed24e2STejun Heo }
231ffed24e2STejun Heo
232ffed24e2STejun Heo /**
233ffed24e2STejun Heo * kernfs_get_inode - get inode for kernfs_node
234c637b8acSTejun Heo * @sb: super block
235ffed24e2STejun Heo * @kn: kernfs_node to allocate inode for
236324a56e1STejun Heo *
237ffed24e2STejun Heo * Get inode for @kn. If such inode doesn't exist, a new inode is
238324a56e1STejun Heo * allocated and basics are initialized. New inode is returned
239324a56e1STejun Heo * locked.
240324a56e1STejun Heo *
241ffed24e2STejun Heo * Locking:
24224b3e3ddSRandy Dunlap * Kernel thread context (may sleep).
243ffed24e2STejun Heo *
244ffed24e2STejun Heo * Return:
24524b3e3ddSRandy Dunlap * Pointer to allocated inode on success, %NULL on failure.
24624b3e3ddSRandy Dunlap */
kernfs_get_inode(struct super_block * sb,struct kernfs_node * kn)247ffed24e2STejun Heo struct inode *kernfs_get_inode(struct super_block *sb, struct kernfs_node *kn)
248c637b8acSTejun Heo {
249ffed24e2STejun Heo struct inode *inode;
250ffed24e2STejun Heo
251ffed24e2STejun Heo inode = iget_locked(sb, kernfs_ino(kn));
25267c0496eSTejun Heo if (inode && (inode->i_state & I_NEW))
253ffed24e2STejun Heo kernfs_init_inode(kn, inode);
254c637b8acSTejun Heo
255ffed24e2STejun Heo return inode;
256ffed24e2STejun Heo }
257ffed24e2STejun Heo
258ffed24e2STejun Heo /*
259ffed24e2STejun Heo * The kernfs_node serves as both an inode and a directory entry for
260c637b8acSTejun Heo * kernfs. To prevent the kernfs inode numbers from being freed
261c637b8acSTejun Heo * prematurely we take a reference to kernfs_node from the kernfs inode. A
262c637b8acSTejun Heo * super_operations.evict_inode() implementation is needed to drop that
263ffed24e2STejun Heo * reference upon inode destruction.
264ffed24e2STejun Heo */
kernfs_evict_inode(struct inode * inode)265ffed24e2STejun Heo void kernfs_evict_inode(struct inode *inode)
266c637b8acSTejun Heo {
267ffed24e2STejun Heo struct kernfs_node *kn = inode->i_private;
268324a56e1STejun Heo
269ffed24e2STejun Heo truncate_inode_pages_final(&inode->i_data);
27091b0abe3SJohannes Weiner clear_inode(inode);
271ffed24e2STejun Heo kernfs_put(kn);
272324a56e1STejun Heo }
273ffed24e2STejun Heo
kernfs_iop_permission(struct mnt_idmap * idmap,struct inode * inode,int mask)274ffed24e2STejun Heo int kernfs_iop_permission(struct mnt_idmap *idmap,
2754609e1f1SChristian Brauner struct inode *inode, int mask)
276549c7297SChristian Brauner {
277ffed24e2STejun Heo struct kernfs_node *kn;
278324a56e1STejun Heo struct kernfs_root *root;
279393c3714SMinchan Kim int ret;
28047b5c64dSIan Kent
281ffed24e2STejun Heo if (mask & MAY_NOT_BLOCK)
282ffed24e2STejun Heo return -ECHILD;
283ffed24e2STejun Heo
284ffed24e2STejun Heo kn = inode->i_private;
285324a56e1STejun Heo root = kernfs_root(kn);
286393c3714SMinchan Kim
287ffed24e2STejun Heo down_read(&root->kernfs_iattr_rwsem);
2889caf6961SImran Khan kernfs_refresh_inode(kn, inode);
289c637b8acSTejun Heo ret = generic_permission(&nop_mnt_idmap, inode, mask);
2904609e1f1SChristian Brauner up_read(&root->kernfs_iattr_rwsem);
2919caf6961SImran Khan
292ffed24e2STejun Heo return ret;
29347b5c64dSIan Kent }
294ffed24e2STejun Heo
kernfs_xattr_get(struct kernfs_node * kn,const char * name,void * value,size_t size)295e72a1a8bSAndreas Gruenbacher int kernfs_xattr_get(struct kernfs_node *kn, const char *name,
2961537ad15SOndrej Mosnacek void *value, size_t size)
297b230d5abSOndrej Mosnacek {
298e72a1a8bSAndreas Gruenbacher struct kernfs_iattrs *attrs = kernfs_iattrs_noalloc(kn);
2991537ad15SOndrej Mosnacek if (!attrs)
300e72a1a8bSAndreas Gruenbacher return -ENODATA;
301d0c9c153SOndrej Mosnacek
302e72a1a8bSAndreas Gruenbacher return simple_xattr_get(&attrs->xattrs, name, value, size);
303e72a1a8bSAndreas Gruenbacher }
304e72a1a8bSAndreas Gruenbacher
kernfs_xattr_set(struct kernfs_node * kn,const char * name,const void * value,size_t size,int flags)305e72a1a8bSAndreas Gruenbacher int kernfs_xattr_set(struct kernfs_node *kn, const char *name,
3061537ad15SOndrej Mosnacek const void *value, size_t size, int flags)
307b230d5abSOndrej Mosnacek {
308e72a1a8bSAndreas Gruenbacher struct simple_xattr *old_xattr;
309*5de75970SHugh Dickins struct kernfs_iattrs *attrs = kernfs_iattrs(kn);
3101537ad15SOndrej Mosnacek if (!attrs)
311e72a1a8bSAndreas Gruenbacher return -ENOMEM;
312e72a1a8bSAndreas Gruenbacher
313e72a1a8bSAndreas Gruenbacher old_xattr = simple_xattr_set(&attrs->xattrs, name, value, size, flags);
314*5de75970SHugh Dickins if (IS_ERR(old_xattr))
315*5de75970SHugh Dickins return PTR_ERR(old_xattr);
316*5de75970SHugh Dickins
317*5de75970SHugh Dickins simple_xattr_free(old_xattr);
318*5de75970SHugh Dickins return 0;
319*5de75970SHugh Dickins }
320e72a1a8bSAndreas Gruenbacher
kernfs_vfs_xattr_get(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * suffix,void * value,size_t size)321e72a1a8bSAndreas Gruenbacher static int kernfs_vfs_xattr_get(const struct xattr_handler *handler,
3221537ad15SOndrej Mosnacek struct dentry *unused, struct inode *inode,
323b230d5abSOndrej Mosnacek const char *suffix, void *value, size_t size)
324b230d5abSOndrej Mosnacek {
325b230d5abSOndrej Mosnacek const char *name = xattr_full_name(handler, suffix);
3261537ad15SOndrej Mosnacek struct kernfs_node *kn = inode->i_private;
327b230d5abSOndrej Mosnacek
328b230d5abSOndrej Mosnacek return kernfs_xattr_get(kn, name, value, size);
3291537ad15SOndrej Mosnacek }
330b230d5abSOndrej Mosnacek
kernfs_vfs_xattr_set(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * unused,struct inode * inode,const char * suffix,const void * value,size_t size,int flags)331b230d5abSOndrej Mosnacek static int kernfs_vfs_xattr_set(const struct xattr_handler *handler,
3321537ad15SOndrej Mosnacek struct mnt_idmap *idmap,
33339f60c1cSChristian Brauner struct dentry *unused, struct inode *inode,
334b230d5abSOndrej Mosnacek const char *suffix, const void *value,
335b230d5abSOndrej Mosnacek size_t size, int flags)
336b230d5abSOndrej Mosnacek {
337b230d5abSOndrej Mosnacek const char *name = xattr_full_name(handler, suffix);
3381537ad15SOndrej Mosnacek struct kernfs_node *kn = inode->i_private;
339b230d5abSOndrej Mosnacek
340b230d5abSOndrej Mosnacek return kernfs_xattr_set(kn, name, value, size, flags);
3411537ad15SOndrej Mosnacek }
342b230d5abSOndrej Mosnacek
kernfs_vfs_user_xattr_add(struct kernfs_node * kn,const char * full_name,struct simple_xattrs * xattrs,const void * value,size_t size,int flags)343b230d5abSOndrej Mosnacek static int kernfs_vfs_user_xattr_add(struct kernfs_node *kn,
3440c47383bSDaniel Xu const char *full_name,
3450c47383bSDaniel Xu struct simple_xattrs *xattrs,
3460c47383bSDaniel Xu const void *value, size_t size, int flags)
3470c47383bSDaniel Xu {
3480c47383bSDaniel Xu atomic_t *sz = &kn->iattr->user_xattr_size;
3490c47383bSDaniel Xu atomic_t *nr = &kn->iattr->nr_user_xattrs;
3500c47383bSDaniel Xu struct simple_xattr *old_xattr;
351*5de75970SHugh Dickins int ret;
3520c47383bSDaniel Xu
3530c47383bSDaniel Xu if (atomic_inc_return(nr) > KERNFS_MAX_USER_XATTRS) {
3540c47383bSDaniel Xu ret = -ENOSPC;
3550c47383bSDaniel Xu goto dec_count_out;
3560c47383bSDaniel Xu }
3570c47383bSDaniel Xu
3580c47383bSDaniel Xu if (atomic_add_return(size, sz) > KERNFS_USER_XATTR_SIZE_LIMIT) {
3590c47383bSDaniel Xu ret = -ENOSPC;
3600c47383bSDaniel Xu goto dec_size_out;
3610c47383bSDaniel Xu }
3620c47383bSDaniel Xu
3630c47383bSDaniel Xu old_xattr = simple_xattr_set(xattrs, full_name, value, size, flags);
364*5de75970SHugh Dickins if (!old_xattr)
365*5de75970SHugh Dickins return 0;
3660c47383bSDaniel Xu
367*5de75970SHugh Dickins if (IS_ERR(old_xattr)) {
368*5de75970SHugh Dickins ret = PTR_ERR(old_xattr);
369*5de75970SHugh Dickins goto dec_size_out;
370*5de75970SHugh Dickins }
371*5de75970SHugh Dickins
372*5de75970SHugh Dickins ret = 0;
373*5de75970SHugh Dickins size = old_xattr->size;
374*5de75970SHugh Dickins simple_xattr_free(old_xattr);
375*5de75970SHugh Dickins dec_size_out:
3760c47383bSDaniel Xu atomic_sub(size, sz);
3770c47383bSDaniel Xu dec_count_out:
3780c47383bSDaniel Xu atomic_dec(nr);
3790c47383bSDaniel Xu return ret;
3800c47383bSDaniel Xu }
3810c47383bSDaniel Xu
kernfs_vfs_user_xattr_rm(struct kernfs_node * kn,const char * full_name,struct simple_xattrs * xattrs,const void * value,size_t size,int flags)3820c47383bSDaniel Xu static int kernfs_vfs_user_xattr_rm(struct kernfs_node *kn,
3830c47383bSDaniel Xu const char *full_name,
3840c47383bSDaniel Xu struct simple_xattrs *xattrs,
3850c47383bSDaniel Xu const void *value, size_t size, int flags)
3860c47383bSDaniel Xu {
3870c47383bSDaniel Xu atomic_t *sz = &kn->iattr->user_xattr_size;
3880c47383bSDaniel Xu atomic_t *nr = &kn->iattr->nr_user_xattrs;
3890c47383bSDaniel Xu struct simple_xattr *old_xattr;
390*5de75970SHugh Dickins
3910c47383bSDaniel Xu old_xattr = simple_xattr_set(xattrs, full_name, value, size, flags);
392*5de75970SHugh Dickins if (!old_xattr)
393*5de75970SHugh Dickins return 0;
394*5de75970SHugh Dickins
3950c47383bSDaniel Xu if (IS_ERR(old_xattr))
396*5de75970SHugh Dickins return PTR_ERR(old_xattr);
397*5de75970SHugh Dickins
398*5de75970SHugh Dickins atomic_sub(old_xattr->size, sz);
399*5de75970SHugh Dickins atomic_dec(nr);
4000c47383bSDaniel Xu simple_xattr_free(old_xattr);
401*5de75970SHugh Dickins return 0;
402*5de75970SHugh Dickins }
4030c47383bSDaniel Xu
kernfs_vfs_user_xattr_set(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * unused,struct inode * inode,const char * suffix,const void * value,size_t size,int flags)4040c47383bSDaniel Xu static int kernfs_vfs_user_xattr_set(const struct xattr_handler *handler,
4050c47383bSDaniel Xu struct mnt_idmap *idmap,
40639f60c1cSChristian Brauner struct dentry *unused, struct inode *inode,
4070c47383bSDaniel Xu const char *suffix, const void *value,
4080c47383bSDaniel Xu size_t size, int flags)
4090c47383bSDaniel Xu {
4100c47383bSDaniel Xu const char *full_name = xattr_full_name(handler, suffix);
4110c47383bSDaniel Xu struct kernfs_node *kn = inode->i_private;
4120c47383bSDaniel Xu struct kernfs_iattrs *attrs;
4130c47383bSDaniel Xu
4140c47383bSDaniel Xu if (!(kernfs_root(kn)->flags & KERNFS_ROOT_SUPPORT_USER_XATTR))
4150c47383bSDaniel Xu return -EOPNOTSUPP;
4160c47383bSDaniel Xu
4170c47383bSDaniel Xu attrs = kernfs_iattrs(kn);
4180c47383bSDaniel Xu if (!attrs)
4190c47383bSDaniel Xu return -ENOMEM;
4200c47383bSDaniel Xu
4210c47383bSDaniel Xu if (value)
4220c47383bSDaniel Xu return kernfs_vfs_user_xattr_add(kn, full_name, &attrs->xattrs,
4230c47383bSDaniel Xu value, size, flags);
4240c47383bSDaniel Xu else
4250c47383bSDaniel Xu return kernfs_vfs_user_xattr_rm(kn, full_name, &attrs->xattrs,
4260c47383bSDaniel Xu value, size, flags);
4270c47383bSDaniel Xu
4280c47383bSDaniel Xu }
4290c47383bSDaniel Xu
4300c47383bSDaniel Xu static const struct xattr_handler kernfs_trusted_xattr_handler = {
431b5a06234SBart Van Assche .prefix = XATTR_TRUSTED_PREFIX,
432e72a1a8bSAndreas Gruenbacher .get = kernfs_vfs_xattr_get,
4331537ad15SOndrej Mosnacek .set = kernfs_vfs_xattr_set,
4341537ad15SOndrej Mosnacek };
435e72a1a8bSAndreas Gruenbacher
436e72a1a8bSAndreas Gruenbacher static const struct xattr_handler kernfs_security_xattr_handler = {
437b5a06234SBart Van Assche .prefix = XATTR_SECURITY_PREFIX,
438e72a1a8bSAndreas Gruenbacher .get = kernfs_vfs_xattr_get,
4391537ad15SOndrej Mosnacek .set = kernfs_vfs_xattr_set,
4401537ad15SOndrej Mosnacek };
441e72a1a8bSAndreas Gruenbacher
442e72a1a8bSAndreas Gruenbacher static const struct xattr_handler kernfs_user_xattr_handler = {
4430c47383bSDaniel Xu .prefix = XATTR_USER_PREFIX,
4440c47383bSDaniel Xu .get = kernfs_vfs_xattr_get,
4450c47383bSDaniel Xu .set = kernfs_vfs_user_xattr_set,
4460c47383bSDaniel Xu };
4470c47383bSDaniel Xu
4480c47383bSDaniel Xu const struct xattr_handler *kernfs_xattr_handlers[] = {
449e72a1a8bSAndreas Gruenbacher &kernfs_trusted_xattr_handler,
450e72a1a8bSAndreas Gruenbacher &kernfs_security_xattr_handler,
451e72a1a8bSAndreas Gruenbacher &kernfs_user_xattr_handler,
4520c47383bSDaniel Xu NULL
453e72a1a8bSAndreas Gruenbacher };
454e72a1a8bSAndreas Gruenbacher