blob: b4c5aa8489d851ea3478c8e25106a0c87846b3f6 [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/xattr.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
4 * Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
5 *
6 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
Mingming Cao617ba132006-10-11 01:20:53 -07007 * Ext4 code with a lot of help from Eric Jarman <ejarman@acm.org>.
Dave Kleikampac27a0e2006-10-11 01:20:50 -07008 * Extended attributes for symlinks and special files added per
9 * suggestion of Luka Renko <luka.renko@hermes.si>.
10 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
11 * Red Hat Inc.
12 * ea-in-inode support by Alex Tomas <alex@clusterfs.com> aka bzzz
13 * and Andreas Gruenbacher <agruen@suse.de>.
14 */
15
16/*
17 * Extended attributes are stored directly in inodes (on file systems with
18 * inodes bigger than 128 bytes) and on additional disk blocks. The i_file_acl
19 * field contains the block number if an inode uses an additional block. All
20 * attributes must fit in the inode and one additional block. Blocks that
21 * contain the identical set of attributes may be shared among several inodes.
22 * Identical blocks are detected by keeping a cache of blocks that have
23 * recently been accessed.
24 *
25 * The attributes in inodes and on blocks have a different header; the entries
26 * are stored in the same format:
27 *
28 * +------------------+
29 * | header |
30 * | entry 1 | |
31 * | entry 2 | | growing downwards
32 * | entry 3 | v
33 * | four null bytes |
34 * | . . . |
35 * | value 1 | ^
36 * | value 3 | | growing upwards
37 * | value 2 | |
38 * +------------------+
39 *
40 * The header is followed by multiple entry descriptors. In disk blocks, the
41 * entry descriptors are kept sorted. In inodes, they are unsorted. The
42 * attribute values are aligned to the end of the block in no specific order.
43 *
44 * Locking strategy
45 * ----------------
Mingming Cao617ba132006-10-11 01:20:53 -070046 * EXT4_I(inode)->i_file_acl is protected by EXT4_I(inode)->xattr_sem.
Dave Kleikampac27a0e2006-10-11 01:20:50 -070047 * EA blocks are only changed if they are exclusive to an inode, so
48 * holding xattr_sem also means that nothing but the EA block's reference
49 * count can change. Multiple writers to the same block are synchronized
50 * by the buffer lock.
51 */
52
53#include <linux/init.h>
54#include <linux/fs.h>
55#include <linux/slab.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070056#include <linux/mbcache.h>
57#include <linux/quotaops.h>
58#include <linux/rwsem.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040059#include "ext4_jbd2.h"
60#include "ext4.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070061#include "xattr.h"
62#include "acl.h"
63
Mingming Cao617ba132006-10-11 01:20:53 -070064#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
65#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
Dave Kleikampac27a0e2006-10-11 01:20:50 -070066#define BFIRST(bh) ENTRY(BHDR(bh)+1)
67#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
68
Mingming Cao617ba132006-10-11 01:20:53 -070069#ifdef EXT4_XATTR_DEBUG
Dave Kleikampac27a0e2006-10-11 01:20:50 -070070# define ea_idebug(inode, f...) do { \
71 printk(KERN_DEBUG "inode %s:%lu: ", \
72 inode->i_sb->s_id, inode->i_ino); \
73 printk(f); \
74 printk("\n"); \
75 } while (0)
76# define ea_bdebug(bh, f...) do { \
77 char b[BDEVNAME_SIZE]; \
78 printk(KERN_DEBUG "block %s:%lu: ", \
79 bdevname(bh->b_bdev, b), \
80 (unsigned long) bh->b_blocknr); \
81 printk(f); \
82 printk("\n"); \
83 } while (0)
84#else
85# define ea_idebug(f...)
86# define ea_bdebug(f...)
87#endif
88
Mingming Cao617ba132006-10-11 01:20:53 -070089static void ext4_xattr_cache_insert(struct buffer_head *);
90static struct buffer_head *ext4_xattr_cache_find(struct inode *,
91 struct ext4_xattr_header *,
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092 struct mb_cache_entry **);
Mingming Cao617ba132006-10-11 01:20:53 -070093static void ext4_xattr_rehash(struct ext4_xattr_header *,
94 struct ext4_xattr_entry *);
Christoph Hellwig431547b2009-11-13 09:52:56 +000095static int ext4_xattr_list(struct dentry *dentry, char *buffer,
Mingming Caod3a95d42008-04-17 10:38:59 -040096 size_t buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070097
Mingming Cao617ba132006-10-11 01:20:53 -070098static struct mb_cache *ext4_xattr_cache;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070099
Mingming Cao617ba132006-10-11 01:20:53 -0700100static struct xattr_handler *ext4_xattr_handler_map[] = {
101 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
Theodore Ts'o03010a32008-10-10 20:02:48 -0400102#ifdef CONFIG_EXT4_FS_POSIX_ACL
Mingming Cao617ba132006-10-11 01:20:53 -0700103 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler,
104 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700105#endif
Mingming Cao617ba132006-10-11 01:20:53 -0700106 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
Theodore Ts'o03010a32008-10-10 20:02:48 -0400107#ifdef CONFIG_EXT4_FS_SECURITY
Mingming Cao617ba132006-10-11 01:20:53 -0700108 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700109#endif
110};
111
Mingming Cao617ba132006-10-11 01:20:53 -0700112struct xattr_handler *ext4_xattr_handlers[] = {
113 &ext4_xattr_user_handler,
114 &ext4_xattr_trusted_handler,
Theodore Ts'o03010a32008-10-10 20:02:48 -0400115#ifdef CONFIG_EXT4_FS_POSIX_ACL
Mingming Cao617ba132006-10-11 01:20:53 -0700116 &ext4_xattr_acl_access_handler,
117 &ext4_xattr_acl_default_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118#endif
Theodore Ts'o03010a32008-10-10 20:02:48 -0400119#ifdef CONFIG_EXT4_FS_SECURITY
Mingming Cao617ba132006-10-11 01:20:53 -0700120 &ext4_xattr_security_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700121#endif
122 NULL
123};
124
125static inline struct xattr_handler *
Mingming Cao617ba132006-10-11 01:20:53 -0700126ext4_xattr_handler(int name_index)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700127{
128 struct xattr_handler *handler = NULL;
129
Mingming Cao617ba132006-10-11 01:20:53 -0700130 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
131 handler = ext4_xattr_handler_map[name_index];
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700132 return handler;
133}
134
135/*
136 * Inode operation listxattr()
137 *
138 * dentry->d_inode->i_mutex: don't care
139 */
140ssize_t
Mingming Cao617ba132006-10-11 01:20:53 -0700141ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700142{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000143 return ext4_xattr_list(dentry, buffer, size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700144}
145
146static int
Mingming Cao617ba132006-10-11 01:20:53 -0700147ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700148{
149 while (!IS_LAST_ENTRY(entry)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700150 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700151 if ((void *)next >= end)
152 return -EIO;
153 entry = next;
154 }
155 return 0;
156}
157
158static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700159ext4_xattr_check_block(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700160{
161 int error;
162
Mingming Cao617ba132006-10-11 01:20:53 -0700163 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700164 BHDR(bh)->h_blocks != cpu_to_le32(1))
165 return -EIO;
Mingming Cao617ba132006-10-11 01:20:53 -0700166 error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700167 return error;
168}
169
170static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700171ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700172{
173 size_t value_size = le32_to_cpu(entry->e_value_size);
174
175 if (entry->e_value_block != 0 || value_size > size ||
176 le16_to_cpu(entry->e_value_offs) + value_size > size)
177 return -EIO;
178 return 0;
179}
180
181static int
Mingming Cao617ba132006-10-11 01:20:53 -0700182ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700183 const char *name, size_t size, int sorted)
184{
Mingming Cao617ba132006-10-11 01:20:53 -0700185 struct ext4_xattr_entry *entry;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700186 size_t name_len;
187 int cmp = 1;
188
189 if (name == NULL)
190 return -EINVAL;
191 name_len = strlen(name);
192 entry = *pentry;
Mingming Cao617ba132006-10-11 01:20:53 -0700193 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700194 cmp = name_index - entry->e_name_index;
195 if (!cmp)
196 cmp = name_len - entry->e_name_len;
197 if (!cmp)
198 cmp = memcmp(name, entry->e_name, name_len);
199 if (cmp <= 0 && (sorted || cmp == 0))
200 break;
201 }
202 *pentry = entry;
Mingming Cao617ba132006-10-11 01:20:53 -0700203 if (!cmp && ext4_xattr_check_entry(entry, size))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700204 return -EIO;
205 return cmp ? -ENODATA : 0;
206}
207
208static int
Mingming Cao617ba132006-10-11 01:20:53 -0700209ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700210 void *buffer, size_t buffer_size)
211{
212 struct buffer_head *bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700213 struct ext4_xattr_entry *entry;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700214 size_t size;
215 int error;
216
217 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
218 name_index, name, buffer, (long)buffer_size);
219
220 error = -ENODATA;
Mingming Cao617ba132006-10-11 01:20:53 -0700221 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700222 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700223 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
224 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700225 if (!bh)
226 goto cleanup;
227 ea_bdebug(bh, "b_count=%d, refcount=%d",
228 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700229 if (ext4_xattr_check_block(bh)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500230bad_block:
231 ext4_error(inode->i_sb,
Mingming Cao2ae02102006-10-11 01:21:11 -0700232 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700233 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700234 error = -EIO;
235 goto cleanup;
236 }
Mingming Cao617ba132006-10-11 01:20:53 -0700237 ext4_xattr_cache_insert(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700238 entry = BFIRST(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700239 error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700240 if (error == -EIO)
241 goto bad_block;
242 if (error)
243 goto cleanup;
244 size = le32_to_cpu(entry->e_value_size);
245 if (buffer) {
246 error = -ERANGE;
247 if (size > buffer_size)
248 goto cleanup;
249 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
250 size);
251 }
252 error = size;
253
254cleanup:
255 brelse(bh);
256 return error;
257}
258
259static int
Mingming Cao617ba132006-10-11 01:20:53 -0700260ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700261 void *buffer, size_t buffer_size)
262{
Mingming Cao617ba132006-10-11 01:20:53 -0700263 struct ext4_xattr_ibody_header *header;
264 struct ext4_xattr_entry *entry;
265 struct ext4_inode *raw_inode;
266 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700267 size_t size;
268 void *end;
269 int error;
270
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500271 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700272 return -ENODATA;
Mingming Cao617ba132006-10-11 01:20:53 -0700273 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700274 if (error)
275 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700276 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700277 header = IHDR(inode, raw_inode);
278 entry = IFIRST(header);
Mingming Cao617ba132006-10-11 01:20:53 -0700279 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
280 error = ext4_xattr_check_names(entry, end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700281 if (error)
282 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700283 error = ext4_xattr_find_entry(&entry, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700284 end - (void *)entry, 0);
285 if (error)
286 goto cleanup;
287 size = le32_to_cpu(entry->e_value_size);
288 if (buffer) {
289 error = -ERANGE;
290 if (size > buffer_size)
291 goto cleanup;
292 memcpy(buffer, (void *)IFIRST(header) +
293 le16_to_cpu(entry->e_value_offs), size);
294 }
295 error = size;
296
297cleanup:
298 brelse(iloc.bh);
299 return error;
300}
301
302/*
Mingming Cao617ba132006-10-11 01:20:53 -0700303 * ext4_xattr_get()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700304 *
305 * Copy an extended attribute into the buffer
306 * provided, or compute the buffer size required.
307 * Buffer is NULL to compute the size of the buffer required.
308 *
309 * Returns a negative error number on failure, or the number of bytes
310 * used / required on success.
311 */
312int
Mingming Cao617ba132006-10-11 01:20:53 -0700313ext4_xattr_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700314 void *buffer, size_t buffer_size)
315{
316 int error;
317
Mingming Cao617ba132006-10-11 01:20:53 -0700318 down_read(&EXT4_I(inode)->xattr_sem);
319 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700320 buffer_size);
321 if (error == -ENODATA)
Mingming Cao617ba132006-10-11 01:20:53 -0700322 error = ext4_xattr_block_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700323 buffer_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700324 up_read(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700325 return error;
326}
327
328static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000329ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700330 char *buffer, size_t buffer_size)
331{
332 size_t rest = buffer_size;
333
Mingming Cao617ba132006-10-11 01:20:53 -0700334 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700335 struct xattr_handler *handler =
Mingming Cao617ba132006-10-11 01:20:53 -0700336 ext4_xattr_handler(entry->e_name_index);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700337
338 if (handler) {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000339 size_t size = handler->list(dentry, buffer, rest,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700340 entry->e_name,
Christoph Hellwig431547b2009-11-13 09:52:56 +0000341 entry->e_name_len,
342 handler->flags);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700343 if (buffer) {
344 if (size > rest)
345 return -ERANGE;
346 buffer += size;
347 }
348 rest -= size;
349 }
350 }
351 return buffer_size - rest;
352}
353
354static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000355ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700356{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000357 struct inode *inode = dentry->d_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700358 struct buffer_head *bh = NULL;
359 int error;
360
361 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
362 buffer, (long)buffer_size);
363
364 error = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700365 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700366 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700367 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
368 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700369 error = -EIO;
370 if (!bh)
371 goto cleanup;
372 ea_bdebug(bh, "b_count=%d, refcount=%d",
373 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700374 if (ext4_xattr_check_block(bh)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500375 ext4_error(inode->i_sb,
Mingming Cao2ae02102006-10-11 01:21:11 -0700376 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700377 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700378 error = -EIO;
379 goto cleanup;
380 }
Mingming Cao617ba132006-10-11 01:20:53 -0700381 ext4_xattr_cache_insert(bh);
Christoph Hellwig431547b2009-11-13 09:52:56 +0000382 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700383
384cleanup:
385 brelse(bh);
386
387 return error;
388}
389
390static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000391ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700392{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000393 struct inode *inode = dentry->d_inode;
Mingming Cao617ba132006-10-11 01:20:53 -0700394 struct ext4_xattr_ibody_header *header;
395 struct ext4_inode *raw_inode;
396 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 void *end;
398 int error;
399
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500400 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700401 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700402 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700403 if (error)
404 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700405 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700406 header = IHDR(inode, raw_inode);
Mingming Cao617ba132006-10-11 01:20:53 -0700407 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
408 error = ext4_xattr_check_names(IFIRST(header), end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700409 if (error)
410 goto cleanup;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000411 error = ext4_xattr_list_entries(dentry, IFIRST(header),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700412 buffer, buffer_size);
413
414cleanup:
415 brelse(iloc.bh);
416 return error;
417}
418
419/*
Mingming Cao617ba132006-10-11 01:20:53 -0700420 * ext4_xattr_list()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700421 *
422 * Copy a list of attribute names into the buffer
423 * provided, or compute the buffer size required.
424 * Buffer is NULL to compute the size of the buffer required.
425 *
426 * Returns a negative error number on failure, or the number of bytes
427 * used / required on success.
428 */
Mingming Caod3a95d42008-04-17 10:38:59 -0400429static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000430ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700431{
432 int i_error, b_error;
433
Christoph Hellwig431547b2009-11-13 09:52:56 +0000434 down_read(&EXT4_I(dentry->d_inode)->xattr_sem);
435 i_error = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700436 if (i_error < 0) {
437 b_error = 0;
438 } else {
439 if (buffer) {
440 buffer += i_error;
441 buffer_size -= i_error;
442 }
Christoph Hellwig431547b2009-11-13 09:52:56 +0000443 b_error = ext4_xattr_block_list(dentry, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700444 if (b_error < 0)
445 i_error = 0;
446 }
Christoph Hellwig431547b2009-11-13 09:52:56 +0000447 up_read(&EXT4_I(dentry->d_inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700448 return i_error + b_error;
449}
450
451/*
Mingming Cao617ba132006-10-11 01:20:53 -0700452 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700453 * not set, set it.
454 */
Mingming Cao617ba132006-10-11 01:20:53 -0700455static void ext4_xattr_update_super_block(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700456 struct super_block *sb)
457{
Mingming Cao617ba132006-10-11 01:20:53 -0700458 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459 return;
460
Mingming Cao617ba132006-10-11 01:20:53 -0700461 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
Andreas Gruenbachered2908f2006-12-06 20:36:16 -0800462 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700463 sb->s_dirt = 1;
Frank Mayhar03901312009-01-07 00:06:22 -0500464 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700465 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700466}
467
468/*
469 * Release the xattr block BH: If the reference count is > 1, decrement
470 * it; otherwise free the block.
471 */
472static void
Mingming Cao617ba132006-10-11 01:20:53 -0700473ext4_xattr_release_block(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700474 struct buffer_head *bh)
475{
476 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800477 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700478
Mingming Cao617ba132006-10-11 01:20:53 -0700479 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800480 error = ext4_journal_get_write_access(handle, bh);
481 if (error)
482 goto out;
483
484 lock_buffer(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700485 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
486 ea_bdebug(bh, "refcount now=0; freeing");
487 if (ce)
488 mb_cache_entry_free(ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700489 get_bh(bh);
Theodore Ts'oe6362602009-11-23 07:17:05 -0500490 ext4_free_blocks(handle, inode, bh, 0, 1,
491 EXT4_FREE_BLOCKS_METADATA |
492 EXT4_FREE_BLOCKS_FORGET);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700493 } else {
Marcin Slusarze8546d02008-04-17 10:38:59 -0400494 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
Frank Mayhar03901312009-01-07 00:06:22 -0500495 error = ext4_handle_dirty_metadata(handle, inode, bh);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800496 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -0500497 ext4_handle_sync(handle);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500498 dquot_free_block(inode, 1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800499 ea_bdebug(bh, "refcount now=%d; releasing",
500 le32_to_cpu(BHDR(bh)->h_refcount));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700501 if (ce)
502 mb_cache_entry_release(ce);
503 }
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800504 unlock_buffer(bh);
505out:
506 ext4_std_error(inode->i_sb, error);
507 return;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700508}
509
Kalpak Shah6dd4ee72007-07-18 09:19:57 -0400510/*
511 * Find the available free space for EAs. This also returns the total number of
512 * bytes used by EA entries.
513 */
514static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
515 size_t *min_offs, void *base, int *total)
516{
517 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
518 *total += EXT4_XATTR_LEN(last->e_name_len);
519 if (!last->e_value_block && last->e_value_size) {
520 size_t offs = le16_to_cpu(last->e_value_offs);
521 if (offs < *min_offs)
522 *min_offs = offs;
523 }
524 }
525 return (*min_offs - ((void *)last - base) - sizeof(__u32));
526}
527
Mingming Cao617ba132006-10-11 01:20:53 -0700528struct ext4_xattr_info {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700529 int name_index;
530 const char *name;
531 const void *value;
532 size_t value_len;
533};
534
Mingming Cao617ba132006-10-11 01:20:53 -0700535struct ext4_xattr_search {
536 struct ext4_xattr_entry *first;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700537 void *base;
538 void *end;
Mingming Cao617ba132006-10-11 01:20:53 -0700539 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700540 int not_found;
541};
542
543static int
Mingming Cao617ba132006-10-11 01:20:53 -0700544ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700545{
Mingming Cao617ba132006-10-11 01:20:53 -0700546 struct ext4_xattr_entry *last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
548
549 /* Compute min_offs and last. */
550 last = s->first;
Mingming Cao617ba132006-10-11 01:20:53 -0700551 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700552 if (!last->e_value_block && last->e_value_size) {
553 size_t offs = le16_to_cpu(last->e_value_offs);
554 if (offs < min_offs)
555 min_offs = offs;
556 }
557 }
558 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
559 if (!s->not_found) {
560 if (!s->here->e_value_block && s->here->e_value_size) {
561 size_t size = le32_to_cpu(s->here->e_value_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700562 free += EXT4_XATTR_SIZE(size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700563 }
Mingming Cao617ba132006-10-11 01:20:53 -0700564 free += EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700565 }
566 if (i->value) {
Mingming Cao617ba132006-10-11 01:20:53 -0700567 if (free < EXT4_XATTR_SIZE(i->value_len) ||
568 free < EXT4_XATTR_LEN(name_len) +
569 EXT4_XATTR_SIZE(i->value_len))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700570 return -ENOSPC;
571 }
572
573 if (i->value && s->not_found) {
574 /* Insert the new name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700575 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700576 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
577 memmove((void *)s->here + size, s->here, rest);
578 memset(s->here, 0, size);
579 s->here->e_name_index = i->name_index;
580 s->here->e_name_len = name_len;
581 memcpy(s->here->e_name, i->name, name_len);
582 } else {
583 if (!s->here->e_value_block && s->here->e_value_size) {
584 void *first_val = s->base + min_offs;
585 size_t offs = le16_to_cpu(s->here->e_value_offs);
586 void *val = s->base + offs;
Mingming Cao617ba132006-10-11 01:20:53 -0700587 size_t size = EXT4_XATTR_SIZE(
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700588 le32_to_cpu(s->here->e_value_size));
589
Mingming Cao617ba132006-10-11 01:20:53 -0700590 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700591 /* The old and the new value have the same
592 size. Just replace. */
593 s->here->e_value_size =
594 cpu_to_le32(i->value_len);
Mingming Cao617ba132006-10-11 01:20:53 -0700595 memset(val + size - EXT4_XATTR_PAD, 0,
596 EXT4_XATTR_PAD); /* Clear pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700597 memcpy(val, i->value, i->value_len);
598 return 0;
599 }
600
601 /* Remove the old value. */
602 memmove(first_val + size, first_val, val - first_val);
603 memset(first_val, 0, size);
604 s->here->e_value_size = 0;
605 s->here->e_value_offs = 0;
606 min_offs += size;
607
608 /* Adjust all value offsets. */
609 last = s->first;
610 while (!IS_LAST_ENTRY(last)) {
611 size_t o = le16_to_cpu(last->e_value_offs);
612 if (!last->e_value_block &&
613 last->e_value_size && o < offs)
614 last->e_value_offs =
615 cpu_to_le16(o + size);
Mingming Cao617ba132006-10-11 01:20:53 -0700616 last = EXT4_XATTR_NEXT(last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700617 }
618 }
619 if (!i->value) {
620 /* Remove the old name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700621 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700622 last = ENTRY((void *)last - size);
623 memmove(s->here, (void *)s->here + size,
624 (void *)last - (void *)s->here + sizeof(__u32));
625 memset(last, 0, size);
626 }
627 }
628
629 if (i->value) {
630 /* Insert the new value. */
631 s->here->e_value_size = cpu_to_le32(i->value_len);
632 if (i->value_len) {
Mingming Cao617ba132006-10-11 01:20:53 -0700633 size_t size = EXT4_XATTR_SIZE(i->value_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700634 void *val = s->base + min_offs - size;
635 s->here->e_value_offs = cpu_to_le16(min_offs - size);
Mingming Cao617ba132006-10-11 01:20:53 -0700636 memset(val + size - EXT4_XATTR_PAD, 0,
637 EXT4_XATTR_PAD); /* Clear the pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700638 memcpy(val, i->value, i->value_len);
639 }
640 }
641 return 0;
642}
643
Mingming Cao617ba132006-10-11 01:20:53 -0700644struct ext4_xattr_block_find {
645 struct ext4_xattr_search s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700646 struct buffer_head *bh;
647};
648
649static int
Mingming Cao617ba132006-10-11 01:20:53 -0700650ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
651 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700652{
653 struct super_block *sb = inode->i_sb;
654 int error;
655
656 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
657 i->name_index, i->name, i->value, (long)i->value_len);
658
Mingming Cao617ba132006-10-11 01:20:53 -0700659 if (EXT4_I(inode)->i_file_acl) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700660 /* The inode already has an extended attribute block. */
Mingming Cao617ba132006-10-11 01:20:53 -0700661 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700662 error = -EIO;
663 if (!bs->bh)
664 goto cleanup;
665 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
666 atomic_read(&(bs->bh->b_count)),
667 le32_to_cpu(BHDR(bs->bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700668 if (ext4_xattr_check_block(bs->bh)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -0500669 ext4_error(sb, "inode %lu: bad block %llu",
670 inode->i_ino, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700671 error = -EIO;
672 goto cleanup;
673 }
674 /* Find the named attribute. */
675 bs->s.base = BHDR(bs->bh);
676 bs->s.first = BFIRST(bs->bh);
677 bs->s.end = bs->bh->b_data + bs->bh->b_size;
678 bs->s.here = bs->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700679 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700680 i->name, bs->bh->b_size, 1);
681 if (error && error != -ENODATA)
682 goto cleanup;
683 bs->s.not_found = error;
684 }
685 error = 0;
686
687cleanup:
688 return error;
689}
690
691static int
Mingming Cao617ba132006-10-11 01:20:53 -0700692ext4_xattr_block_set(handle_t *handle, struct inode *inode,
693 struct ext4_xattr_info *i,
694 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700695{
696 struct super_block *sb = inode->i_sb;
697 struct buffer_head *new_bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700698 struct ext4_xattr_search *s = &bs->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700699 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800700 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700701
Mingming Cao617ba132006-10-11 01:20:53 -0700702#define header(x) ((struct ext4_xattr_header *)(x))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700703
704 if (i->value && i->value_len > sb->s_blocksize)
705 return -ENOSPC;
706 if (s->base) {
Mingming Cao617ba132006-10-11 01:20:53 -0700707 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700708 bs->bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800709 error = ext4_journal_get_write_access(handle, bs->bh);
710 if (error)
711 goto cleanup;
712 lock_buffer(bs->bh);
713
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700714 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
715 if (ce) {
716 mb_cache_entry_free(ce);
717 ce = NULL;
718 }
719 ea_bdebug(bs->bh, "modifying in-place");
Mingming Cao617ba132006-10-11 01:20:53 -0700720 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700721 if (!error) {
722 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700723 ext4_xattr_rehash(header(s->base),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700724 s->here);
Mingming Cao617ba132006-10-11 01:20:53 -0700725 ext4_xattr_cache_insert(bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700726 }
727 unlock_buffer(bs->bh);
728 if (error == -EIO)
729 goto bad_block;
730 if (!error)
Frank Mayhar03901312009-01-07 00:06:22 -0500731 error = ext4_handle_dirty_metadata(handle,
732 inode,
733 bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700734 if (error)
735 goto cleanup;
736 goto inserted;
737 } else {
738 int offset = (char *)s->here - bs->bh->b_data;
739
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800740 unlock_buffer(bs->bh);
741 jbd2_journal_release_buffer(handle, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700742 if (ce) {
743 mb_cache_entry_release(ce);
744 ce = NULL;
745 }
746 ea_bdebug(bs->bh, "cloning");
Josef Bacik216553c2008-04-29 22:02:02 -0400747 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700748 error = -ENOMEM;
749 if (s->base == NULL)
750 goto cleanup;
751 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
752 s->first = ENTRY(header(s->base)+1);
753 header(s->base)->h_refcount = cpu_to_le32(1);
754 s->here = ENTRY(s->base + offset);
755 s->end = s->base + bs->bh->b_size;
756 }
757 } else {
758 /* Allocate a buffer where we construct the new block. */
Josef Bacik216553c2008-04-29 22:02:02 -0400759 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700760 /* assert(header == s->base) */
761 error = -ENOMEM;
762 if (s->base == NULL)
763 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700764 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700765 header(s->base)->h_blocks = cpu_to_le32(1);
766 header(s->base)->h_refcount = cpu_to_le32(1);
767 s->first = ENTRY(header(s->base)+1);
768 s->here = ENTRY(header(s->base)+1);
769 s->end = s->base + sb->s_blocksize;
770 }
771
Mingming Cao617ba132006-10-11 01:20:53 -0700772 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700773 if (error == -EIO)
774 goto bad_block;
775 if (error)
776 goto cleanup;
777 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700778 ext4_xattr_rehash(header(s->base), s->here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700779
780inserted:
781 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700782 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700783 if (new_bh) {
784 /* We found an identical block in the cache. */
785 if (new_bh == bs->bh)
786 ea_bdebug(new_bh, "keeping");
787 else {
788 /* The old block is released after updating
789 the inode. */
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500790 error = dquot_alloc_block(inode, 1);
791 if (error)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700792 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700793 error = ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700794 new_bh);
795 if (error)
796 goto cleanup_dquot;
797 lock_buffer(new_bh);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400798 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700799 ea_bdebug(new_bh, "reusing; refcount now=%d",
800 le32_to_cpu(BHDR(new_bh)->h_refcount));
801 unlock_buffer(new_bh);
Frank Mayhar03901312009-01-07 00:06:22 -0500802 error = ext4_handle_dirty_metadata(handle,
803 inode,
804 new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700805 if (error)
806 goto cleanup_dquot;
807 }
808 mb_cache_entry_release(ce);
809 ce = NULL;
810 } else if (bs->bh && s->base == bs->bh->b_data) {
811 /* We were modifying this block in-place. */
812 ea_bdebug(bs->bh, "keeping this block");
813 new_bh = bs->bh;
814 get_bh(new_bh);
815 } else {
816 /* We need to allocate a new block */
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400817 ext4_fsblk_t goal, block;
818
819 goal = ext4_group_first_block_no(sb,
Akinobu Mitad00a6d72008-04-17 10:38:59 -0400820 EXT4_I(inode)->i_block_group);
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400821
822 /* non-extent files can't have physical blocks past 2^32 */
823 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
824 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
825
826 block = ext4_new_meta_blocks(handle, inode,
Theodore Ts'o97df5d12008-12-12 12:41:28 -0500827 goal, NULL, &error);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700828 if (error)
829 goto cleanup;
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400830
831 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
832 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
833
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700834 ea_idebug(inode, "creating block %d", block);
835
836 new_bh = sb_getblk(sb, block);
837 if (!new_bh) {
838getblk_failed:
Theodore Ts'oe6362602009-11-23 07:17:05 -0500839 ext4_free_blocks(handle, inode, 0, block, 1,
840 EXT4_FREE_BLOCKS_METADATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700841 error = -EIO;
842 goto cleanup;
843 }
844 lock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700845 error = ext4_journal_get_create_access(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700846 if (error) {
847 unlock_buffer(new_bh);
848 goto getblk_failed;
849 }
850 memcpy(new_bh->b_data, s->base, new_bh->b_size);
851 set_buffer_uptodate(new_bh);
852 unlock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700853 ext4_xattr_cache_insert(new_bh);
Frank Mayhar03901312009-01-07 00:06:22 -0500854 error = ext4_handle_dirty_metadata(handle,
855 inode, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700856 if (error)
857 goto cleanup;
858 }
859 }
860
861 /* Update the inode. */
Mingming Cao617ba132006-10-11 01:20:53 -0700862 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700863
864 /* Drop the previous xattr block. */
865 if (bs->bh && bs->bh != new_bh)
Mingming Cao617ba132006-10-11 01:20:53 -0700866 ext4_xattr_release_block(handle, inode, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700867 error = 0;
868
869cleanup:
870 if (ce)
871 mb_cache_entry_release(ce);
872 brelse(new_bh);
873 if (!(bs->bh && s->base == bs->bh->b_data))
874 kfree(s->base);
875
876 return error;
877
878cleanup_dquot:
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500879 dquot_free_block(inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700880 goto cleanup;
881
882bad_block:
Eric Sandeen12062dd2010-02-15 14:19:27 -0500883 ext4_error(inode->i_sb, "inode %lu: bad block %llu",
884 inode->i_ino, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700885 goto cleanup;
886
887#undef header
888}
889
Mingming Cao617ba132006-10-11 01:20:53 -0700890struct ext4_xattr_ibody_find {
891 struct ext4_xattr_search s;
892 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700893};
894
895static int
Mingming Cao617ba132006-10-11 01:20:53 -0700896ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
897 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700898{
Mingming Cao617ba132006-10-11 01:20:53 -0700899 struct ext4_xattr_ibody_header *header;
900 struct ext4_inode *raw_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700901 int error;
902
Mingming Cao617ba132006-10-11 01:20:53 -0700903 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700904 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700905 raw_inode = ext4_raw_inode(&is->iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700906 header = IHDR(inode, raw_inode);
907 is->s.base = is->s.first = IFIRST(header);
908 is->s.here = is->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700909 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500910 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700911 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700912 if (error)
913 return error;
914 /* Find the named attribute. */
Mingming Cao617ba132006-10-11 01:20:53 -0700915 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700916 i->name, is->s.end -
917 (void *)is->s.base, 0);
918 if (error && error != -ENODATA)
919 return error;
920 is->s.not_found = error;
921 }
922 return 0;
923}
924
925static int
Mingming Cao617ba132006-10-11 01:20:53 -0700926ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
927 struct ext4_xattr_info *i,
928 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700929{
Mingming Cao617ba132006-10-11 01:20:53 -0700930 struct ext4_xattr_ibody_header *header;
931 struct ext4_xattr_search *s = &is->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700932 int error;
933
Mingming Cao617ba132006-10-11 01:20:53 -0700934 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700935 return -ENOSPC;
Mingming Cao617ba132006-10-11 01:20:53 -0700936 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700937 if (error)
938 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700939 header = IHDR(inode, ext4_raw_inode(&is->iloc));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700940 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700941 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500942 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700943 } else {
944 header->h_magic = cpu_to_le32(0);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500945 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700946 }
947 return 0;
948}
949
950/*
Mingming Cao617ba132006-10-11 01:20:53 -0700951 * ext4_xattr_set_handle()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700952 *
953 * Create, replace or remove an extended attribute for this inode. Buffer
954 * is NULL to remove an existing extended attribute, and non-NULL to
955 * either replace an existing extended attribute, or create a new extended
956 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
957 * specify that an extended attribute must exist and must not exist
958 * previous to the call, respectively.
959 *
960 * Returns 0, or a negative error number on failure.
961 */
962int
Mingming Cao617ba132006-10-11 01:20:53 -0700963ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700964 const char *name, const void *value, size_t value_len,
965 int flags)
966{
Mingming Cao617ba132006-10-11 01:20:53 -0700967 struct ext4_xattr_info i = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700968 .name_index = name_index,
969 .name = name,
970 .value = value,
971 .value_len = value_len,
972
973 };
Mingming Cao617ba132006-10-11 01:20:53 -0700974 struct ext4_xattr_ibody_find is = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700975 .s = { .not_found = -ENODATA, },
976 };
Mingming Cao617ba132006-10-11 01:20:53 -0700977 struct ext4_xattr_block_find bs = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700978 .s = { .not_found = -ENODATA, },
979 };
Kalpak Shah4d20c682008-10-08 23:21:54 -0400980 unsigned long no_expand;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700981 int error;
982
983 if (!name)
984 return -EINVAL;
985 if (strlen(name) > 255)
986 return -ERANGE;
Mingming Cao617ba132006-10-11 01:20:53 -0700987 down_write(&EXT4_I(inode)->xattr_sem);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500988 no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
989 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
Kalpak Shah4d20c682008-10-08 23:21:54 -0400990
Mingming Cao617ba132006-10-11 01:20:53 -0700991 error = ext4_get_inode_loc(inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700992 if (error)
993 goto cleanup;
994
Eric Sandeen86ebfd02009-11-15 15:30:52 -0500995 error = ext4_journal_get_write_access(handle, is.iloc.bh);
996 if (error)
997 goto cleanup;
998
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500999 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
Mingming Cao617ba132006-10-11 01:20:53 -07001000 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
1001 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001002 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001003 }
1004
Mingming Cao617ba132006-10-11 01:20:53 -07001005 error = ext4_xattr_ibody_find(inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001006 if (error)
1007 goto cleanup;
1008 if (is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001009 error = ext4_xattr_block_find(inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001010 if (error)
1011 goto cleanup;
1012 if (is.s.not_found && bs.s.not_found) {
1013 error = -ENODATA;
1014 if (flags & XATTR_REPLACE)
1015 goto cleanup;
1016 error = 0;
1017 if (!value)
1018 goto cleanup;
1019 } else {
1020 error = -EEXIST;
1021 if (flags & XATTR_CREATE)
1022 goto cleanup;
1023 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001024 if (!value) {
1025 if (!is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001026 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001027 else if (!bs.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001028 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001029 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07001030 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001031 if (!error && !bs.s.not_found) {
1032 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001033 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001034 } else if (error == -ENOSPC) {
Tiger Yang7e01c8e2008-05-14 16:05:47 -07001035 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
1036 error = ext4_xattr_block_find(inode, &i, &bs);
1037 if (error)
1038 goto cleanup;
1039 }
Mingming Cao617ba132006-10-11 01:20:53 -07001040 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001041 if (error)
1042 goto cleanup;
1043 if (!is.s.not_found) {
1044 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001045 error = ext4_xattr_ibody_set(handle, inode, &i,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001046 &is);
1047 }
1048 }
1049 }
1050 if (!error) {
Mingming Cao617ba132006-10-11 01:20:53 -07001051 ext4_xattr_update_super_block(handle, inode->i_sb);
Kalpak Shahef7f3832007-07-18 09:15:20 -04001052 inode->i_ctime = ext4_current_time(inode);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001053 if (!value)
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001054 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
Mingming Cao617ba132006-10-11 01:20:53 -07001055 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001056 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001057 * The bh is consumed by ext4_mark_iloc_dirty, even with
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001058 * error != 0.
1059 */
1060 is.iloc.bh = NULL;
1061 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05001062 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001063 }
1064
1065cleanup:
1066 brelse(is.iloc.bh);
1067 brelse(bs.bh);
Kalpak Shah4d20c682008-10-08 23:21:54 -04001068 if (no_expand == 0)
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001069 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
Mingming Cao617ba132006-10-11 01:20:53 -07001070 up_write(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001071 return error;
1072}
1073
1074/*
Mingming Cao617ba132006-10-11 01:20:53 -07001075 * ext4_xattr_set()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001076 *
Mingming Cao617ba132006-10-11 01:20:53 -07001077 * Like ext4_xattr_set_handle, but start from an inode. This extended
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001078 * attribute modification is a filesystem transaction by itself.
1079 *
1080 * Returns 0, or a negative error number on failure.
1081 */
1082int
Mingming Cao617ba132006-10-11 01:20:53 -07001083ext4_xattr_set(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001084 const void *value, size_t value_len, int flags)
1085{
1086 handle_t *handle;
1087 int error, retries = 0;
1088
1089retry:
Mingming Cao617ba132006-10-11 01:20:53 -07001090 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001091 if (IS_ERR(handle)) {
1092 error = PTR_ERR(handle);
1093 } else {
1094 int error2;
1095
Mingming Cao617ba132006-10-11 01:20:53 -07001096 error = ext4_xattr_set_handle(handle, inode, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001097 value, value_len, flags);
Mingming Cao617ba132006-10-11 01:20:53 -07001098 error2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001099 if (error == -ENOSPC &&
Mingming Cao617ba132006-10-11 01:20:53 -07001100 ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001101 goto retry;
1102 if (error == 0)
1103 error = error2;
1104 }
1105
1106 return error;
1107}
1108
1109/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001110 * Shift the EA entries in the inode to create space for the increased
1111 * i_extra_isize.
1112 */
1113static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1114 int value_offs_shift, void *to,
1115 void *from, size_t n, int blocksize)
1116{
1117 struct ext4_xattr_entry *last = entry;
1118 int new_offs;
1119
1120 /* Adjust the value offsets of the entries */
1121 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1122 if (!last->e_value_block && last->e_value_size) {
1123 new_offs = le16_to_cpu(last->e_value_offs) +
1124 value_offs_shift;
1125 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1126 > blocksize);
1127 last->e_value_offs = cpu_to_le16(new_offs);
1128 }
1129 }
1130 /* Shift the entries by n bytes */
1131 memmove(to, from, n);
1132}
1133
1134/*
1135 * Expand an inode by new_extra_isize bytes when EAs are present.
1136 * Returns 0 on success or negative error number on failure.
1137 */
1138int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1139 struct ext4_inode *raw_inode, handle_t *handle)
1140{
1141 struct ext4_xattr_ibody_header *header;
1142 struct ext4_xattr_entry *entry, *last, *first;
1143 struct buffer_head *bh = NULL;
1144 struct ext4_xattr_ibody_find *is = NULL;
1145 struct ext4_xattr_block_find *bs = NULL;
1146 char *buffer = NULL, *b_entry_name = NULL;
1147 size_t min_offs, free;
1148 int total_ino, total_blk;
1149 void *base, *start, *end;
1150 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001151 int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001152
1153 down_write(&EXT4_I(inode)->xattr_sem);
1154retry:
1155 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1156 up_write(&EXT4_I(inode)->xattr_sem);
1157 return 0;
1158 }
1159
1160 header = IHDR(inode, raw_inode);
1161 entry = IFIRST(header);
1162
1163 /*
1164 * Check if enough free space is available in the inode to shift the
1165 * entries ahead by new_extra_isize.
1166 */
1167
1168 base = start = entry;
1169 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1170 min_offs = end - base;
1171 last = entry;
1172 total_ino = sizeof(struct ext4_xattr_ibody_header);
1173
1174 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1175 if (free >= new_extra_isize) {
1176 entry = IFIRST(header);
1177 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1178 - new_extra_isize, (void *)raw_inode +
1179 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1180 (void *)header, total_ino,
1181 inode->i_sb->s_blocksize);
1182 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1183 error = 0;
1184 goto cleanup;
1185 }
1186
1187 /*
1188 * Enough free space isn't available in the inode, check if
1189 * EA block can hold new_extra_isize bytes.
1190 */
1191 if (EXT4_I(inode)->i_file_acl) {
1192 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1193 error = -EIO;
1194 if (!bh)
1195 goto cleanup;
1196 if (ext4_xattr_check_block(bh)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001197 ext4_error(inode->i_sb, "inode %lu: bad block %llu",
1198 inode->i_ino, EXT4_I(inode)->i_file_acl);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001199 error = -EIO;
1200 goto cleanup;
1201 }
1202 base = BHDR(bh);
1203 first = BFIRST(bh);
1204 end = bh->b_data + bh->b_size;
1205 min_offs = end - base;
1206 free = ext4_xattr_free_space(first, &min_offs, base,
1207 &total_blk);
1208 if (free < new_extra_isize) {
1209 if (!tried_min_extra_isize && s_min_extra_isize) {
1210 tried_min_extra_isize++;
1211 new_extra_isize = s_min_extra_isize;
1212 brelse(bh);
1213 goto retry;
1214 }
1215 error = -1;
1216 goto cleanup;
1217 }
1218 } else {
1219 free = inode->i_sb->s_blocksize;
1220 }
1221
1222 while (new_extra_isize > 0) {
1223 size_t offs, size, entry_size;
1224 struct ext4_xattr_entry *small_entry = NULL;
1225 struct ext4_xattr_info i = {
1226 .value = NULL,
1227 .value_len = 0,
1228 };
1229 unsigned int total_size; /* EA entry size + value size */
1230 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1231 unsigned int min_total_size = ~0U;
1232
1233 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1234 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1235 if (!is || !bs) {
1236 error = -ENOMEM;
1237 goto cleanup;
1238 }
1239
1240 is->s.not_found = -ENODATA;
1241 bs->s.not_found = -ENODATA;
1242 is->iloc.bh = NULL;
1243 bs->bh = NULL;
1244
1245 last = IFIRST(header);
1246 /* Find the entry best suited to be pushed into EA block */
1247 entry = NULL;
1248 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1249 total_size =
1250 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1251 EXT4_XATTR_LEN(last->e_name_len);
1252 if (total_size <= free && total_size < min_total_size) {
1253 if (total_size < new_extra_isize) {
1254 small_entry = last;
1255 } else {
1256 entry = last;
1257 min_total_size = total_size;
1258 }
1259 }
1260 }
1261
1262 if (entry == NULL) {
1263 if (small_entry) {
1264 entry = small_entry;
1265 } else {
1266 if (!tried_min_extra_isize &&
1267 s_min_extra_isize) {
1268 tried_min_extra_isize++;
1269 new_extra_isize = s_min_extra_isize;
1270 goto retry;
1271 }
1272 error = -1;
1273 goto cleanup;
1274 }
1275 }
1276 offs = le16_to_cpu(entry->e_value_offs);
1277 size = le32_to_cpu(entry->e_value_size);
1278 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1279 i.name_index = entry->e_name_index,
1280 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1281 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1282 if (!buffer || !b_entry_name) {
1283 error = -ENOMEM;
1284 goto cleanup;
1285 }
1286 /* Save the entry name and the entry value */
1287 memcpy(buffer, (void *)IFIRST(header) + offs,
1288 EXT4_XATTR_SIZE(size));
1289 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1290 b_entry_name[entry->e_name_len] = '\0';
1291 i.name = b_entry_name;
1292
1293 error = ext4_get_inode_loc(inode, &is->iloc);
1294 if (error)
1295 goto cleanup;
1296
1297 error = ext4_xattr_ibody_find(inode, &i, is);
1298 if (error)
1299 goto cleanup;
1300
1301 /* Remove the chosen entry from the inode */
1302 error = ext4_xattr_ibody_set(handle, inode, &i, is);
Roel Kluin9aaab052010-02-15 14:26:16 -05001303 if (error)
1304 goto cleanup;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001305
1306 entry = IFIRST(header);
1307 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1308 shift_bytes = new_extra_isize;
1309 else
1310 shift_bytes = entry_size + size;
1311 /* Adjust the offsets and shift the remaining entries ahead */
1312 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1313 shift_bytes, (void *)raw_inode +
1314 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1315 (void *)header, total_ino - entry_size,
1316 inode->i_sb->s_blocksize);
1317
1318 extra_isize += shift_bytes;
1319 new_extra_isize -= shift_bytes;
1320 EXT4_I(inode)->i_extra_isize = extra_isize;
1321
1322 i.name = b_entry_name;
1323 i.value = buffer;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001324 i.value_len = size;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001325 error = ext4_xattr_block_find(inode, &i, bs);
1326 if (error)
1327 goto cleanup;
1328
1329 /* Add entry which was removed from the inode into the block */
1330 error = ext4_xattr_block_set(handle, inode, &i, bs);
1331 if (error)
1332 goto cleanup;
1333 kfree(b_entry_name);
1334 kfree(buffer);
Julia Lawalld3533d72009-12-23 07:52:31 -05001335 b_entry_name = NULL;
1336 buffer = NULL;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001337 brelse(is->iloc.bh);
1338 kfree(is);
1339 kfree(bs);
1340 }
1341 brelse(bh);
1342 up_write(&EXT4_I(inode)->xattr_sem);
1343 return 0;
1344
1345cleanup:
1346 kfree(b_entry_name);
1347 kfree(buffer);
1348 if (is)
1349 brelse(is->iloc.bh);
1350 kfree(is);
1351 kfree(bs);
1352 brelse(bh);
1353 up_write(&EXT4_I(inode)->xattr_sem);
1354 return error;
1355}
1356
1357
1358
1359/*
Mingming Cao617ba132006-10-11 01:20:53 -07001360 * ext4_xattr_delete_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001361 *
1362 * Free extended attribute resources associated with this inode. This
1363 * is called immediately before an inode is freed. We have exclusive
1364 * access to the inode.
1365 */
1366void
Mingming Cao617ba132006-10-11 01:20:53 -07001367ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001368{
1369 struct buffer_head *bh = NULL;
1370
Mingming Cao617ba132006-10-11 01:20:53 -07001371 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001372 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -07001373 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001374 if (!bh) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001375 ext4_error(inode->i_sb, "inode %lu: block %llu read error",
1376 inode->i_ino, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001377 goto cleanup;
1378 }
Mingming Cao617ba132006-10-11 01:20:53 -07001379 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001380 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001381 ext4_error(inode->i_sb, "inode %lu: bad block %llu",
1382 inode->i_ino, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001383 goto cleanup;
1384 }
Mingming Cao617ba132006-10-11 01:20:53 -07001385 ext4_xattr_release_block(handle, inode, bh);
1386 EXT4_I(inode)->i_file_acl = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001387
1388cleanup:
1389 brelse(bh);
1390}
1391
1392/*
Mingming Cao617ba132006-10-11 01:20:53 -07001393 * ext4_xattr_put_super()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001394 *
1395 * This is called when a file system is unmounted.
1396 */
1397void
Mingming Cao617ba132006-10-11 01:20:53 -07001398ext4_xattr_put_super(struct super_block *sb)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001399{
1400 mb_cache_shrink(sb->s_bdev);
1401}
1402
1403/*
Mingming Cao617ba132006-10-11 01:20:53 -07001404 * ext4_xattr_cache_insert()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001405 *
1406 * Create a new entry in the extended attribute cache, and insert
1407 * it unless such an entry is already in the cache.
1408 *
1409 * Returns 0, or a negative error number on failure.
1410 */
1411static void
Mingming Cao617ba132006-10-11 01:20:53 -07001412ext4_xattr_cache_insert(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001413{
1414 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1415 struct mb_cache_entry *ce;
1416 int error;
1417
Jan Kara335e92e2008-04-15 14:34:43 -07001418 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001419 if (!ce) {
1420 ea_bdebug(bh, "out of memory");
1421 return;
1422 }
1423 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash);
1424 if (error) {
1425 mb_cache_entry_free(ce);
1426 if (error == -EBUSY) {
1427 ea_bdebug(bh, "already in cache");
1428 error = 0;
1429 }
1430 } else {
1431 ea_bdebug(bh, "inserting [%x]", (int)hash);
1432 mb_cache_entry_release(ce);
1433 }
1434}
1435
1436/*
Mingming Cao617ba132006-10-11 01:20:53 -07001437 * ext4_xattr_cmp()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001438 *
1439 * Compare two extended attribute blocks for equality.
1440 *
1441 * Returns 0 if the blocks are equal, 1 if they differ, and
1442 * a negative error number on errors.
1443 */
1444static int
Mingming Cao617ba132006-10-11 01:20:53 -07001445ext4_xattr_cmp(struct ext4_xattr_header *header1,
1446 struct ext4_xattr_header *header2)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001447{
Mingming Cao617ba132006-10-11 01:20:53 -07001448 struct ext4_xattr_entry *entry1, *entry2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001449
1450 entry1 = ENTRY(header1+1);
1451 entry2 = ENTRY(header2+1);
1452 while (!IS_LAST_ENTRY(entry1)) {
1453 if (IS_LAST_ENTRY(entry2))
1454 return 1;
1455 if (entry1->e_hash != entry2->e_hash ||
1456 entry1->e_name_index != entry2->e_name_index ||
1457 entry1->e_name_len != entry2->e_name_len ||
1458 entry1->e_value_size != entry2->e_value_size ||
1459 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1460 return 1;
1461 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1462 return -EIO;
1463 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1464 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1465 le32_to_cpu(entry1->e_value_size)))
1466 return 1;
1467
Mingming Cao617ba132006-10-11 01:20:53 -07001468 entry1 = EXT4_XATTR_NEXT(entry1);
1469 entry2 = EXT4_XATTR_NEXT(entry2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001470 }
1471 if (!IS_LAST_ENTRY(entry2))
1472 return 1;
1473 return 0;
1474}
1475
1476/*
Mingming Cao617ba132006-10-11 01:20:53 -07001477 * ext4_xattr_cache_find()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001478 *
1479 * Find an identical extended attribute block.
1480 *
1481 * Returns a pointer to the block found, or NULL if such a block was
1482 * not found or an error occurred.
1483 */
1484static struct buffer_head *
Mingming Cao617ba132006-10-11 01:20:53 -07001485ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001486 struct mb_cache_entry **pce)
1487{
1488 __u32 hash = le32_to_cpu(header->h_hash);
1489 struct mb_cache_entry *ce;
1490
1491 if (!header->h_hash)
1492 return NULL; /* never share */
1493 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1494again:
Mingming Cao617ba132006-10-11 01:20:53 -07001495 ce = mb_cache_entry_find_first(ext4_xattr_cache, 0,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001496 inode->i_sb->s_bdev, hash);
1497 while (ce) {
1498 struct buffer_head *bh;
1499
1500 if (IS_ERR(ce)) {
1501 if (PTR_ERR(ce) == -EAGAIN)
1502 goto again;
1503 break;
1504 }
1505 bh = sb_bread(inode->i_sb, ce->e_block);
1506 if (!bh) {
Eric Sandeen12062dd2010-02-15 14:19:27 -05001507 ext4_error(inode->i_sb,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001508 "inode %lu: block %lu read error",
1509 inode->i_ino, (unsigned long) ce->e_block);
1510 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
Mingming Cao617ba132006-10-11 01:20:53 -07001511 EXT4_XATTR_REFCOUNT_MAX) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001512 ea_idebug(inode, "block %lu refcount %d>=%d",
1513 (unsigned long) ce->e_block,
1514 le32_to_cpu(BHDR(bh)->h_refcount),
Mingming Cao617ba132006-10-11 01:20:53 -07001515 EXT4_XATTR_REFCOUNT_MAX);
1516 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001517 *pce = ce;
1518 return bh;
1519 }
1520 brelse(bh);
1521 ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash);
1522 }
1523 return NULL;
1524}
1525
1526#define NAME_HASH_SHIFT 5
1527#define VALUE_HASH_SHIFT 16
1528
1529/*
Mingming Cao617ba132006-10-11 01:20:53 -07001530 * ext4_xattr_hash_entry()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001531 *
1532 * Compute the hash of an extended attribute.
1533 */
Mingming Cao617ba132006-10-11 01:20:53 -07001534static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1535 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001536{
1537 __u32 hash = 0;
1538 char *name = entry->e_name;
1539 int n;
1540
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001541 for (n = 0; n < entry->e_name_len; n++) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001542 hash = (hash << NAME_HASH_SHIFT) ^
1543 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1544 *name++;
1545 }
1546
1547 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1548 __le32 *value = (__le32 *)((char *)header +
1549 le16_to_cpu(entry->e_value_offs));
1550 for (n = (le32_to_cpu(entry->e_value_size) +
Mingming Cao617ba132006-10-11 01:20:53 -07001551 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001552 hash = (hash << VALUE_HASH_SHIFT) ^
1553 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1554 le32_to_cpu(*value++);
1555 }
1556 }
1557 entry->e_hash = cpu_to_le32(hash);
1558}
1559
1560#undef NAME_HASH_SHIFT
1561#undef VALUE_HASH_SHIFT
1562
1563#define BLOCK_HASH_SHIFT 16
1564
1565/*
Mingming Cao617ba132006-10-11 01:20:53 -07001566 * ext4_xattr_rehash()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001567 *
1568 * Re-compute the extended attribute hash value after an entry has changed.
1569 */
Mingming Cao617ba132006-10-11 01:20:53 -07001570static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1571 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001572{
Mingming Cao617ba132006-10-11 01:20:53 -07001573 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001574 __u32 hash = 0;
1575
Mingming Cao617ba132006-10-11 01:20:53 -07001576 ext4_xattr_hash_entry(header, entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001577 here = ENTRY(header+1);
1578 while (!IS_LAST_ENTRY(here)) {
1579 if (!here->e_hash) {
1580 /* Block is not shared if an entry's hash value == 0 */
1581 hash = 0;
1582 break;
1583 }
1584 hash = (hash << BLOCK_HASH_SHIFT) ^
1585 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1586 le32_to_cpu(here->e_hash);
Mingming Cao617ba132006-10-11 01:20:53 -07001587 here = EXT4_XATTR_NEXT(here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001588 }
1589 header->h_hash = cpu_to_le32(hash);
1590}
1591
1592#undef BLOCK_HASH_SHIFT
1593
1594int __init
Mingming Cao617ba132006-10-11 01:20:53 -07001595init_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001596{
Mingming Cao617ba132006-10-11 01:20:53 -07001597 ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001598 sizeof(struct mb_cache_entry) +
1599 sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6);
Mingming Cao617ba132006-10-11 01:20:53 -07001600 if (!ext4_xattr_cache)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001601 return -ENOMEM;
1602 return 0;
1603}
1604
1605void
Mingming Cao617ba132006-10-11 01:20:53 -07001606exit_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001607{
Mingming Cao617ba132006-10-11 01:20:53 -07001608 if (ext4_xattr_cache)
1609 mb_cache_destroy(ext4_xattr_cache);
1610 ext4_xattr_cache = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001611}