blob: fc32176eee39ede67320bebeb44a80812d7d0f21 [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
Stephen Hemminger11e27522010-05-13 17:53:18 -0700100static const struct xattr_handler *ext4_xattr_handler_map[] = {
Mingming Cao617ba132006-10-11 01:20:53 -0700101 [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
Stephen Hemminger11e27522010-05-13 17:53:18 -0700112const struct xattr_handler *ext4_xattr_handlers[] = {
Mingming Cao617ba132006-10-11 01:20:53 -0700113 &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
Stephen Hemminger11e27522010-05-13 17:53:18 -0700125static inline const struct xattr_handler *
Mingming Cao617ba132006-10-11 01:20:53 -0700126ext4_xattr_handler(int name_index)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700127{
Stephen Hemminger11e27522010-05-13 17:53:18 -0700128 const struct xattr_handler *handler = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700129
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:
Theodore Ts'o24676da2010-05-16 21:00:00 -0400231 EXT4_ERROR_INODE(inode, "bad block %llu",
232 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700233 error = -EIO;
234 goto cleanup;
235 }
Mingming Cao617ba132006-10-11 01:20:53 -0700236 ext4_xattr_cache_insert(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700237 entry = BFIRST(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700238 error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700239 if (error == -EIO)
240 goto bad_block;
241 if (error)
242 goto cleanup;
243 size = le32_to_cpu(entry->e_value_size);
244 if (buffer) {
245 error = -ERANGE;
246 if (size > buffer_size)
247 goto cleanup;
248 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
249 size);
250 }
251 error = size;
252
253cleanup:
254 brelse(bh);
255 return error;
256}
257
258static int
Mingming Cao617ba132006-10-11 01:20:53 -0700259ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700260 void *buffer, size_t buffer_size)
261{
Mingming Cao617ba132006-10-11 01:20:53 -0700262 struct ext4_xattr_ibody_header *header;
263 struct ext4_xattr_entry *entry;
264 struct ext4_inode *raw_inode;
265 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700266 size_t size;
267 void *end;
268 int error;
269
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500270 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700271 return -ENODATA;
Mingming Cao617ba132006-10-11 01:20:53 -0700272 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700273 if (error)
274 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700275 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700276 header = IHDR(inode, raw_inode);
277 entry = IFIRST(header);
Mingming Cao617ba132006-10-11 01:20:53 -0700278 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
279 error = ext4_xattr_check_names(entry, end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700280 if (error)
281 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700282 error = ext4_xattr_find_entry(&entry, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700283 end - (void *)entry, 0);
284 if (error)
285 goto cleanup;
286 size = le32_to_cpu(entry->e_value_size);
287 if (buffer) {
288 error = -ERANGE;
289 if (size > buffer_size)
290 goto cleanup;
291 memcpy(buffer, (void *)IFIRST(header) +
292 le16_to_cpu(entry->e_value_offs), size);
293 }
294 error = size;
295
296cleanup:
297 brelse(iloc.bh);
298 return error;
299}
300
301/*
Mingming Cao617ba132006-10-11 01:20:53 -0700302 * ext4_xattr_get()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700303 *
304 * Copy an extended attribute into the buffer
305 * provided, or compute the buffer size required.
306 * Buffer is NULL to compute the size of the buffer required.
307 *
308 * Returns a negative error number on failure, or the number of bytes
309 * used / required on success.
310 */
311int
Mingming Cao617ba132006-10-11 01:20:53 -0700312ext4_xattr_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700313 void *buffer, size_t buffer_size)
314{
315 int error;
316
Mingming Cao617ba132006-10-11 01:20:53 -0700317 down_read(&EXT4_I(inode)->xattr_sem);
318 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700319 buffer_size);
320 if (error == -ENODATA)
Mingming Cao617ba132006-10-11 01:20:53 -0700321 error = ext4_xattr_block_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700322 buffer_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700323 up_read(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700324 return error;
325}
326
327static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000328ext4_xattr_list_entries(struct dentry *dentry, struct ext4_xattr_entry *entry,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700329 char *buffer, size_t buffer_size)
330{
331 size_t rest = buffer_size;
332
Mingming Cao617ba132006-10-11 01:20:53 -0700333 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
Stephen Hemminger11e27522010-05-13 17:53:18 -0700334 const struct xattr_handler *handler =
Mingming Cao617ba132006-10-11 01:20:53 -0700335 ext4_xattr_handler(entry->e_name_index);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700336
337 if (handler) {
Christoph Hellwig431547b2009-11-13 09:52:56 +0000338 size_t size = handler->list(dentry, buffer, rest,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700339 entry->e_name,
Christoph Hellwig431547b2009-11-13 09:52:56 +0000340 entry->e_name_len,
341 handler->flags);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700342 if (buffer) {
343 if (size > rest)
344 return -ERANGE;
345 buffer += size;
346 }
347 rest -= size;
348 }
349 }
350 return buffer_size - rest;
351}
352
353static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000354ext4_xattr_block_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700355{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000356 struct inode *inode = dentry->d_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700357 struct buffer_head *bh = NULL;
358 int error;
359
360 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
361 buffer, (long)buffer_size);
362
363 error = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700364 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700365 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700366 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
367 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700368 error = -EIO;
369 if (!bh)
370 goto cleanup;
371 ea_bdebug(bh, "b_count=%d, refcount=%d",
372 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700373 if (ext4_xattr_check_block(bh)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -0400374 EXT4_ERROR_INODE(inode, "bad block %llu",
375 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700376 error = -EIO;
377 goto cleanup;
378 }
Mingming Cao617ba132006-10-11 01:20:53 -0700379 ext4_xattr_cache_insert(bh);
Christoph Hellwig431547b2009-11-13 09:52:56 +0000380 error = ext4_xattr_list_entries(dentry, BFIRST(bh), buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700381
382cleanup:
383 brelse(bh);
384
385 return error;
386}
387
388static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000389ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700390{
Christoph Hellwig431547b2009-11-13 09:52:56 +0000391 struct inode *inode = dentry->d_inode;
Mingming Cao617ba132006-10-11 01:20:53 -0700392 struct ext4_xattr_ibody_header *header;
393 struct ext4_inode *raw_inode;
394 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700395 void *end;
396 int error;
397
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500398 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700399 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700400 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700401 if (error)
402 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700403 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700404 header = IHDR(inode, raw_inode);
Mingming Cao617ba132006-10-11 01:20:53 -0700405 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
406 error = ext4_xattr_check_names(IFIRST(header), end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700407 if (error)
408 goto cleanup;
Christoph Hellwig431547b2009-11-13 09:52:56 +0000409 error = ext4_xattr_list_entries(dentry, IFIRST(header),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700410 buffer, buffer_size);
411
412cleanup:
413 brelse(iloc.bh);
414 return error;
415}
416
417/*
Mingming Cao617ba132006-10-11 01:20:53 -0700418 * ext4_xattr_list()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700419 *
420 * Copy a list of attribute names into the buffer
421 * provided, or compute the buffer size required.
422 * Buffer is NULL to compute the size of the buffer required.
423 *
424 * Returns a negative error number on failure, or the number of bytes
425 * used / required on success.
426 */
Mingming Caod3a95d42008-04-17 10:38:59 -0400427static int
Christoph Hellwig431547b2009-11-13 09:52:56 +0000428ext4_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700429{
Theodore Ts'oeaeef862011-01-10 12:10:07 -0500430 int ret, ret2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700431
Christoph Hellwig431547b2009-11-13 09:52:56 +0000432 down_read(&EXT4_I(dentry->d_inode)->xattr_sem);
Theodore Ts'oeaeef862011-01-10 12:10:07 -0500433 ret = ret2 = ext4_xattr_ibody_list(dentry, buffer, buffer_size);
434 if (ret < 0)
435 goto errout;
436 if (buffer) {
437 buffer += ret;
438 buffer_size -= ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700439 }
Theodore Ts'oeaeef862011-01-10 12:10:07 -0500440 ret = ext4_xattr_block_list(dentry, buffer, buffer_size);
441 if (ret < 0)
442 goto errout;
443 ret += ret2;
444errout:
Christoph Hellwig431547b2009-11-13 09:52:56 +0000445 up_read(&EXT4_I(dentry->d_inode)->xattr_sem);
Theodore Ts'oeaeef862011-01-10 12:10:07 -0500446 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700447}
448
449/*
Mingming Cao617ba132006-10-11 01:20:53 -0700450 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700451 * not set, set it.
452 */
Mingming Cao617ba132006-10-11 01:20:53 -0700453static void ext4_xattr_update_super_block(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700454 struct super_block *sb)
455{
Mingming Cao617ba132006-10-11 01:20:53 -0700456 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700457 return;
458
Mingming Cao617ba132006-10-11 01:20:53 -0700459 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
Andreas Gruenbachered2908f2006-12-06 20:36:16 -0800460 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
Theodore Ts'oa0375152010-06-11 23:14:04 -0400461 ext4_handle_dirty_super(handle, sb);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700462 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700463}
464
465/*
466 * Release the xattr block BH: If the reference count is > 1, decrement
467 * it; otherwise free the block.
468 */
469static void
Mingming Cao617ba132006-10-11 01:20:53 -0700470ext4_xattr_release_block(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700471 struct buffer_head *bh)
472{
473 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800474 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700475
Mingming Cao617ba132006-10-11 01:20:53 -0700476 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800477 error = ext4_journal_get_write_access(handle, bh);
478 if (error)
479 goto out;
480
481 lock_buffer(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700482 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
483 ea_bdebug(bh, "refcount now=0; freeing");
484 if (ce)
485 mb_cache_entry_free(ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700486 get_bh(bh);
Theodore Ts'oe6362602009-11-23 07:17:05 -0500487 ext4_free_blocks(handle, inode, bh, 0, 1,
488 EXT4_FREE_BLOCKS_METADATA |
489 EXT4_FREE_BLOCKS_FORGET);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700490 } else {
Marcin Slusarze8546d02008-04-17 10:38:59 -0400491 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
Frank Mayhar03901312009-01-07 00:06:22 -0500492 error = ext4_handle_dirty_metadata(handle, inode, bh);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800493 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -0500494 ext4_handle_sync(handle);
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500495 dquot_free_block(inode, 1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800496 ea_bdebug(bh, "refcount now=%d; releasing",
497 le32_to_cpu(BHDR(bh)->h_refcount));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700498 if (ce)
499 mb_cache_entry_release(ce);
500 }
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800501 unlock_buffer(bh);
502out:
503 ext4_std_error(inode->i_sb, error);
504 return;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700505}
506
Kalpak Shah6dd4ee72007-07-18 09:19:57 -0400507/*
508 * Find the available free space for EAs. This also returns the total number of
509 * bytes used by EA entries.
510 */
511static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
512 size_t *min_offs, void *base, int *total)
513{
514 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
515 *total += EXT4_XATTR_LEN(last->e_name_len);
516 if (!last->e_value_block && last->e_value_size) {
517 size_t offs = le16_to_cpu(last->e_value_offs);
518 if (offs < *min_offs)
519 *min_offs = offs;
520 }
521 }
522 return (*min_offs - ((void *)last - base) - sizeof(__u32));
523}
524
Mingming Cao617ba132006-10-11 01:20:53 -0700525struct ext4_xattr_info {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700526 int name_index;
527 const char *name;
528 const void *value;
529 size_t value_len;
530};
531
Mingming Cao617ba132006-10-11 01:20:53 -0700532struct ext4_xattr_search {
533 struct ext4_xattr_entry *first;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700534 void *base;
535 void *end;
Mingming Cao617ba132006-10-11 01:20:53 -0700536 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700537 int not_found;
538};
539
540static int
Mingming Cao617ba132006-10-11 01:20:53 -0700541ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700542{
Mingming Cao617ba132006-10-11 01:20:53 -0700543 struct ext4_xattr_entry *last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700544 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
545
546 /* Compute min_offs and last. */
547 last = s->first;
Mingming Cao617ba132006-10-11 01:20:53 -0700548 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700549 if (!last->e_value_block && last->e_value_size) {
550 size_t offs = le16_to_cpu(last->e_value_offs);
551 if (offs < min_offs)
552 min_offs = offs;
553 }
554 }
555 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
556 if (!s->not_found) {
557 if (!s->here->e_value_block && s->here->e_value_size) {
558 size_t size = le32_to_cpu(s->here->e_value_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700559 free += EXT4_XATTR_SIZE(size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700560 }
Mingming Cao617ba132006-10-11 01:20:53 -0700561 free += EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700562 }
563 if (i->value) {
Mingming Cao617ba132006-10-11 01:20:53 -0700564 if (free < EXT4_XATTR_SIZE(i->value_len) ||
565 free < EXT4_XATTR_LEN(name_len) +
566 EXT4_XATTR_SIZE(i->value_len))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700567 return -ENOSPC;
568 }
569
570 if (i->value && s->not_found) {
571 /* Insert the new name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700572 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700573 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
574 memmove((void *)s->here + size, s->here, rest);
575 memset(s->here, 0, size);
576 s->here->e_name_index = i->name_index;
577 s->here->e_name_len = name_len;
578 memcpy(s->here->e_name, i->name, name_len);
579 } else {
580 if (!s->here->e_value_block && s->here->e_value_size) {
581 void *first_val = s->base + min_offs;
582 size_t offs = le16_to_cpu(s->here->e_value_offs);
583 void *val = s->base + offs;
Mingming Cao617ba132006-10-11 01:20:53 -0700584 size_t size = EXT4_XATTR_SIZE(
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700585 le32_to_cpu(s->here->e_value_size));
586
Mingming Cao617ba132006-10-11 01:20:53 -0700587 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700588 /* The old and the new value have the same
589 size. Just replace. */
590 s->here->e_value_size =
591 cpu_to_le32(i->value_len);
Mingming Cao617ba132006-10-11 01:20:53 -0700592 memset(val + size - EXT4_XATTR_PAD, 0,
593 EXT4_XATTR_PAD); /* Clear pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700594 memcpy(val, i->value, i->value_len);
595 return 0;
596 }
597
598 /* Remove the old value. */
599 memmove(first_val + size, first_val, val - first_val);
600 memset(first_val, 0, size);
601 s->here->e_value_size = 0;
602 s->here->e_value_offs = 0;
603 min_offs += size;
604
605 /* Adjust all value offsets. */
606 last = s->first;
607 while (!IS_LAST_ENTRY(last)) {
608 size_t o = le16_to_cpu(last->e_value_offs);
609 if (!last->e_value_block &&
610 last->e_value_size && o < offs)
611 last->e_value_offs =
612 cpu_to_le16(o + size);
Mingming Cao617ba132006-10-11 01:20:53 -0700613 last = EXT4_XATTR_NEXT(last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700614 }
615 }
616 if (!i->value) {
617 /* Remove the old name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700618 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700619 last = ENTRY((void *)last - size);
620 memmove(s->here, (void *)s->here + size,
621 (void *)last - (void *)s->here + sizeof(__u32));
622 memset(last, 0, size);
623 }
624 }
625
626 if (i->value) {
627 /* Insert the new value. */
628 s->here->e_value_size = cpu_to_le32(i->value_len);
629 if (i->value_len) {
Mingming Cao617ba132006-10-11 01:20:53 -0700630 size_t size = EXT4_XATTR_SIZE(i->value_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700631 void *val = s->base + min_offs - size;
632 s->here->e_value_offs = cpu_to_le16(min_offs - size);
Mingming Cao617ba132006-10-11 01:20:53 -0700633 memset(val + size - EXT4_XATTR_PAD, 0,
634 EXT4_XATTR_PAD); /* Clear the pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700635 memcpy(val, i->value, i->value_len);
636 }
637 }
638 return 0;
639}
640
Mingming Cao617ba132006-10-11 01:20:53 -0700641struct ext4_xattr_block_find {
642 struct ext4_xattr_search s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700643 struct buffer_head *bh;
644};
645
646static int
Mingming Cao617ba132006-10-11 01:20:53 -0700647ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
648 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700649{
650 struct super_block *sb = inode->i_sb;
651 int error;
652
653 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
654 i->name_index, i->name, i->value, (long)i->value_len);
655
Mingming Cao617ba132006-10-11 01:20:53 -0700656 if (EXT4_I(inode)->i_file_acl) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700657 /* The inode already has an extended attribute block. */
Mingming Cao617ba132006-10-11 01:20:53 -0700658 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700659 error = -EIO;
660 if (!bs->bh)
661 goto cleanup;
662 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
663 atomic_read(&(bs->bh->b_count)),
664 le32_to_cpu(BHDR(bs->bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700665 if (ext4_xattr_check_block(bs->bh)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -0400666 EXT4_ERROR_INODE(inode, "bad block %llu",
667 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700668 error = -EIO;
669 goto cleanup;
670 }
671 /* Find the named attribute. */
672 bs->s.base = BHDR(bs->bh);
673 bs->s.first = BFIRST(bs->bh);
674 bs->s.end = bs->bh->b_data + bs->bh->b_size;
675 bs->s.here = bs->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700676 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700677 i->name, bs->bh->b_size, 1);
678 if (error && error != -ENODATA)
679 goto cleanup;
680 bs->s.not_found = error;
681 }
682 error = 0;
683
684cleanup:
685 return error;
686}
687
688static int
Mingming Cao617ba132006-10-11 01:20:53 -0700689ext4_xattr_block_set(handle_t *handle, struct inode *inode,
690 struct ext4_xattr_info *i,
691 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700692{
693 struct super_block *sb = inode->i_sb;
694 struct buffer_head *new_bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700695 struct ext4_xattr_search *s = &bs->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700696 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800697 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700698
Mingming Cao617ba132006-10-11 01:20:53 -0700699#define header(x) ((struct ext4_xattr_header *)(x))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700700
701 if (i->value && i->value_len > sb->s_blocksize)
702 return -ENOSPC;
703 if (s->base) {
Mingming Cao617ba132006-10-11 01:20:53 -0700704 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700705 bs->bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800706 error = ext4_journal_get_write_access(handle, bs->bh);
707 if (error)
708 goto cleanup;
709 lock_buffer(bs->bh);
710
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700711 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
712 if (ce) {
713 mb_cache_entry_free(ce);
714 ce = NULL;
715 }
716 ea_bdebug(bs->bh, "modifying in-place");
Mingming Cao617ba132006-10-11 01:20:53 -0700717 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700718 if (!error) {
719 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700720 ext4_xattr_rehash(header(s->base),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700721 s->here);
Mingming Cao617ba132006-10-11 01:20:53 -0700722 ext4_xattr_cache_insert(bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700723 }
724 unlock_buffer(bs->bh);
725 if (error == -EIO)
726 goto bad_block;
727 if (!error)
Frank Mayhar03901312009-01-07 00:06:22 -0500728 error = ext4_handle_dirty_metadata(handle,
729 inode,
730 bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700731 if (error)
732 goto cleanup;
733 goto inserted;
734 } else {
735 int offset = (char *)s->here - bs->bh->b_data;
736
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800737 unlock_buffer(bs->bh);
738 jbd2_journal_release_buffer(handle, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700739 if (ce) {
740 mb_cache_entry_release(ce);
741 ce = NULL;
742 }
743 ea_bdebug(bs->bh, "cloning");
Josef Bacik216553c2008-04-29 22:02:02 -0400744 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700745 error = -ENOMEM;
746 if (s->base == NULL)
747 goto cleanup;
748 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
749 s->first = ENTRY(header(s->base)+1);
750 header(s->base)->h_refcount = cpu_to_le32(1);
751 s->here = ENTRY(s->base + offset);
752 s->end = s->base + bs->bh->b_size;
753 }
754 } else {
755 /* Allocate a buffer where we construct the new block. */
Josef Bacik216553c2008-04-29 22:02:02 -0400756 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700757 /* assert(header == s->base) */
758 error = -ENOMEM;
759 if (s->base == NULL)
760 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700761 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700762 header(s->base)->h_blocks = cpu_to_le32(1);
763 header(s->base)->h_refcount = cpu_to_le32(1);
764 s->first = ENTRY(header(s->base)+1);
765 s->here = ENTRY(header(s->base)+1);
766 s->end = s->base + sb->s_blocksize;
767 }
768
Mingming Cao617ba132006-10-11 01:20:53 -0700769 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700770 if (error == -EIO)
771 goto bad_block;
772 if (error)
773 goto cleanup;
774 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700775 ext4_xattr_rehash(header(s->base), s->here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700776
777inserted:
778 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700779 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700780 if (new_bh) {
781 /* We found an identical block in the cache. */
782 if (new_bh == bs->bh)
783 ea_bdebug(new_bh, "keeping");
784 else {
785 /* The old block is released after updating
786 the inode. */
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500787 error = dquot_alloc_block(inode, 1);
788 if (error)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700789 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700790 error = ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700791 new_bh);
792 if (error)
793 goto cleanup_dquot;
794 lock_buffer(new_bh);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400795 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700796 ea_bdebug(new_bh, "reusing; refcount now=%d",
797 le32_to_cpu(BHDR(new_bh)->h_refcount));
798 unlock_buffer(new_bh);
Frank Mayhar03901312009-01-07 00:06:22 -0500799 error = ext4_handle_dirty_metadata(handle,
800 inode,
801 new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700802 if (error)
803 goto cleanup_dquot;
804 }
805 mb_cache_entry_release(ce);
806 ce = NULL;
807 } else if (bs->bh && s->base == bs->bh->b_data) {
808 /* We were modifying this block in-place. */
809 ea_bdebug(bs->bh, "keeping this block");
810 new_bh = bs->bh;
811 get_bh(new_bh);
812 } else {
813 /* We need to allocate a new block */
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400814 ext4_fsblk_t goal, block;
815
816 goal = ext4_group_first_block_no(sb,
Akinobu Mitad00a6d72008-04-17 10:38:59 -0400817 EXT4_I(inode)->i_block_group);
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400818
819 /* non-extent files can't have physical blocks past 2^32 */
Dmitry Monakhov12e9b892010-05-16 22:00:00 -0400820 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400821 goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
822
823 block = ext4_new_meta_blocks(handle, inode,
Theodore Ts'o97df5d12008-12-12 12:41:28 -0500824 goal, NULL, &error);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700825 if (error)
826 goto cleanup;
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400827
Dmitry Monakhov12e9b892010-05-16 22:00:00 -0400828 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
Eric Sandeenfb0a3872009-09-16 14:45:10 -0400829 BUG_ON(block > EXT4_MAX_BLOCK_FILE_PHYS);
830
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700831 ea_idebug(inode, "creating block %d", block);
832
833 new_bh = sb_getblk(sb, block);
834 if (!new_bh) {
835getblk_failed:
Theodore Ts'oe6362602009-11-23 07:17:05 -0500836 ext4_free_blocks(handle, inode, 0, block, 1,
837 EXT4_FREE_BLOCKS_METADATA);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700838 error = -EIO;
839 goto cleanup;
840 }
841 lock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700842 error = ext4_journal_get_create_access(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700843 if (error) {
844 unlock_buffer(new_bh);
845 goto getblk_failed;
846 }
847 memcpy(new_bh->b_data, s->base, new_bh->b_size);
848 set_buffer_uptodate(new_bh);
849 unlock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700850 ext4_xattr_cache_insert(new_bh);
Frank Mayhar03901312009-01-07 00:06:22 -0500851 error = ext4_handle_dirty_metadata(handle,
852 inode, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700853 if (error)
854 goto cleanup;
855 }
856 }
857
858 /* Update the inode. */
Mingming Cao617ba132006-10-11 01:20:53 -0700859 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700860
861 /* Drop the previous xattr block. */
862 if (bs->bh && bs->bh != new_bh)
Mingming Cao617ba132006-10-11 01:20:53 -0700863 ext4_xattr_release_block(handle, inode, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700864 error = 0;
865
866cleanup:
867 if (ce)
868 mb_cache_entry_release(ce);
869 brelse(new_bh);
870 if (!(bs->bh && s->base == bs->bh->b_data))
871 kfree(s->base);
872
873 return error;
874
875cleanup_dquot:
Christoph Hellwig5dd40562010-03-03 09:05:00 -0500876 dquot_free_block(inode, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700877 goto cleanup;
878
879bad_block:
Theodore Ts'o24676da2010-05-16 21:00:00 -0400880 EXT4_ERROR_INODE(inode, "bad block %llu",
881 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700882 goto cleanup;
883
884#undef header
885}
886
Mingming Cao617ba132006-10-11 01:20:53 -0700887struct ext4_xattr_ibody_find {
888 struct ext4_xattr_search s;
889 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700890};
891
892static int
Mingming Cao617ba132006-10-11 01:20:53 -0700893ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
894 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700895{
Mingming Cao617ba132006-10-11 01:20:53 -0700896 struct ext4_xattr_ibody_header *header;
897 struct ext4_inode *raw_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700898 int error;
899
Mingming Cao617ba132006-10-11 01:20:53 -0700900 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700901 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700902 raw_inode = ext4_raw_inode(&is->iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700903 header = IHDR(inode, raw_inode);
904 is->s.base = is->s.first = IFIRST(header);
905 is->s.here = is->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700906 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500907 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700908 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700909 if (error)
910 return error;
911 /* Find the named attribute. */
Mingming Cao617ba132006-10-11 01:20:53 -0700912 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700913 i->name, is->s.end -
914 (void *)is->s.base, 0);
915 if (error && error != -ENODATA)
916 return error;
917 is->s.not_found = error;
918 }
919 return 0;
920}
921
922static int
Mingming Cao617ba132006-10-11 01:20:53 -0700923ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
924 struct ext4_xattr_info *i,
925 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700926{
Mingming Cao617ba132006-10-11 01:20:53 -0700927 struct ext4_xattr_ibody_header *header;
928 struct ext4_xattr_search *s = &is->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700929 int error;
930
Mingming Cao617ba132006-10-11 01:20:53 -0700931 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700932 return -ENOSPC;
Mingming Cao617ba132006-10-11 01:20:53 -0700933 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700934 if (error)
935 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700936 header = IHDR(inode, ext4_raw_inode(&is->iloc));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700937 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700938 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500939 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700940 } else {
941 header->h_magic = cpu_to_le32(0);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500942 ext4_clear_inode_state(inode, EXT4_STATE_XATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700943 }
944 return 0;
945}
946
947/*
Mingming Cao617ba132006-10-11 01:20:53 -0700948 * ext4_xattr_set_handle()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700949 *
Wang Sheng-Hui6e9510b2011-01-10 12:10:30 -0500950 * Create, replace or remove an extended attribute for this inode. Value
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700951 * is NULL to remove an existing extended attribute, and non-NULL to
952 * either replace an existing extended attribute, or create a new extended
953 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
954 * specify that an extended attribute must exist and must not exist
955 * previous to the call, respectively.
956 *
957 * Returns 0, or a negative error number on failure.
958 */
959int
Mingming Cao617ba132006-10-11 01:20:53 -0700960ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700961 const char *name, const void *value, size_t value_len,
962 int flags)
963{
Mingming Cao617ba132006-10-11 01:20:53 -0700964 struct ext4_xattr_info i = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700965 .name_index = name_index,
966 .name = name,
967 .value = value,
968 .value_len = value_len,
969
970 };
Mingming Cao617ba132006-10-11 01:20:53 -0700971 struct ext4_xattr_ibody_find is = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700972 .s = { .not_found = -ENODATA, },
973 };
Mingming Cao617ba132006-10-11 01:20:53 -0700974 struct ext4_xattr_block_find bs = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700975 .s = { .not_found = -ENODATA, },
976 };
Kalpak Shah4d20c682008-10-08 23:21:54 -0400977 unsigned long no_expand;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700978 int error;
979
980 if (!name)
981 return -EINVAL;
982 if (strlen(name) > 255)
983 return -ERANGE;
Mingming Cao617ba132006-10-11 01:20:53 -0700984 down_write(&EXT4_I(inode)->xattr_sem);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500985 no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
986 ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
Kalpak Shah4d20c682008-10-08 23:21:54 -0400987
Mingming Cao617ba132006-10-11 01:20:53 -0700988 error = ext4_get_inode_loc(inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700989 if (error)
990 goto cleanup;
991
Eric Sandeen86ebfd02009-11-15 15:30:52 -0500992 error = ext4_journal_get_write_access(handle, is.iloc.bh);
993 if (error)
994 goto cleanup;
995
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500996 if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700997 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
998 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -0500999 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001000 }
1001
Mingming Cao617ba132006-10-11 01:20:53 -07001002 error = ext4_xattr_ibody_find(inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001003 if (error)
1004 goto cleanup;
1005 if (is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001006 error = ext4_xattr_block_find(inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001007 if (error)
1008 goto cleanup;
1009 if (is.s.not_found && bs.s.not_found) {
1010 error = -ENODATA;
1011 if (flags & XATTR_REPLACE)
1012 goto cleanup;
1013 error = 0;
1014 if (!value)
1015 goto cleanup;
1016 } else {
1017 error = -EEXIST;
1018 if (flags & XATTR_CREATE)
1019 goto cleanup;
1020 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001021 if (!value) {
1022 if (!is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001023 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001024 else if (!bs.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001025 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001026 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07001027 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001028 if (!error && !bs.s.not_found) {
1029 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001030 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001031 } else if (error == -ENOSPC) {
Tiger Yang7e01c8e2008-05-14 16:05:47 -07001032 if (EXT4_I(inode)->i_file_acl && !bs.s.base) {
1033 error = ext4_xattr_block_find(inode, &i, &bs);
1034 if (error)
1035 goto cleanup;
1036 }
Mingming Cao617ba132006-10-11 01:20:53 -07001037 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001038 if (error)
1039 goto cleanup;
1040 if (!is.s.not_found) {
1041 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001042 error = ext4_xattr_ibody_set(handle, inode, &i,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001043 &is);
1044 }
1045 }
1046 }
1047 if (!error) {
Mingming Cao617ba132006-10-11 01:20:53 -07001048 ext4_xattr_update_super_block(handle, inode->i_sb);
Kalpak Shahef7f3832007-07-18 09:15:20 -04001049 inode->i_ctime = ext4_current_time(inode);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001050 if (!value)
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001051 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
Mingming Cao617ba132006-10-11 01:20:53 -07001052 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001053 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001054 * The bh is consumed by ext4_mark_iloc_dirty, even with
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001055 * error != 0.
1056 */
1057 is.iloc.bh = NULL;
1058 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05001059 ext4_handle_sync(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001060 }
1061
1062cleanup:
1063 brelse(is.iloc.bh);
1064 brelse(bs.bh);
Kalpak Shah4d20c682008-10-08 23:21:54 -04001065 if (no_expand == 0)
Theodore Ts'o19f5fb72010-01-24 14:34:07 -05001066 ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
Mingming Cao617ba132006-10-11 01:20:53 -07001067 up_write(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001068 return error;
1069}
1070
1071/*
Mingming Cao617ba132006-10-11 01:20:53 -07001072 * ext4_xattr_set()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001073 *
Mingming Cao617ba132006-10-11 01:20:53 -07001074 * Like ext4_xattr_set_handle, but start from an inode. This extended
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001075 * attribute modification is a filesystem transaction by itself.
1076 *
1077 * Returns 0, or a negative error number on failure.
1078 */
1079int
Mingming Cao617ba132006-10-11 01:20:53 -07001080ext4_xattr_set(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001081 const void *value, size_t value_len, int flags)
1082{
1083 handle_t *handle;
1084 int error, retries = 0;
1085
1086retry:
Mingming Cao617ba132006-10-11 01:20:53 -07001087 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001088 if (IS_ERR(handle)) {
1089 error = PTR_ERR(handle);
1090 } else {
1091 int error2;
1092
Mingming Cao617ba132006-10-11 01:20:53 -07001093 error = ext4_xattr_set_handle(handle, inode, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001094 value, value_len, flags);
Mingming Cao617ba132006-10-11 01:20:53 -07001095 error2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001096 if (error == -ENOSPC &&
Mingming Cao617ba132006-10-11 01:20:53 -07001097 ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001098 goto retry;
1099 if (error == 0)
1100 error = error2;
1101 }
1102
1103 return error;
1104}
1105
1106/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001107 * Shift the EA entries in the inode to create space for the increased
1108 * i_extra_isize.
1109 */
1110static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1111 int value_offs_shift, void *to,
1112 void *from, size_t n, int blocksize)
1113{
1114 struct ext4_xattr_entry *last = entry;
1115 int new_offs;
1116
1117 /* Adjust the value offsets of the entries */
1118 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1119 if (!last->e_value_block && last->e_value_size) {
1120 new_offs = le16_to_cpu(last->e_value_offs) +
1121 value_offs_shift;
1122 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1123 > blocksize);
1124 last->e_value_offs = cpu_to_le16(new_offs);
1125 }
1126 }
1127 /* Shift the entries by n bytes */
1128 memmove(to, from, n);
1129}
1130
1131/*
1132 * Expand an inode by new_extra_isize bytes when EAs are present.
1133 * Returns 0 on success or negative error number on failure.
1134 */
1135int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1136 struct ext4_inode *raw_inode, handle_t *handle)
1137{
1138 struct ext4_xattr_ibody_header *header;
1139 struct ext4_xattr_entry *entry, *last, *first;
1140 struct buffer_head *bh = NULL;
1141 struct ext4_xattr_ibody_find *is = NULL;
1142 struct ext4_xattr_block_find *bs = NULL;
1143 char *buffer = NULL, *b_entry_name = NULL;
1144 size_t min_offs, free;
1145 int total_ino, total_blk;
1146 void *base, *start, *end;
1147 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001148 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 -04001149
1150 down_write(&EXT4_I(inode)->xattr_sem);
1151retry:
1152 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1153 up_write(&EXT4_I(inode)->xattr_sem);
1154 return 0;
1155 }
1156
1157 header = IHDR(inode, raw_inode);
1158 entry = IFIRST(header);
1159
1160 /*
1161 * Check if enough free space is available in the inode to shift the
1162 * entries ahead by new_extra_isize.
1163 */
1164
1165 base = start = entry;
1166 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1167 min_offs = end - base;
1168 last = entry;
1169 total_ino = sizeof(struct ext4_xattr_ibody_header);
1170
1171 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1172 if (free >= new_extra_isize) {
1173 entry = IFIRST(header);
1174 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1175 - new_extra_isize, (void *)raw_inode +
1176 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1177 (void *)header, total_ino,
1178 inode->i_sb->s_blocksize);
1179 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1180 error = 0;
1181 goto cleanup;
1182 }
1183
1184 /*
1185 * Enough free space isn't available in the inode, check if
1186 * EA block can hold new_extra_isize bytes.
1187 */
1188 if (EXT4_I(inode)->i_file_acl) {
1189 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1190 error = -EIO;
1191 if (!bh)
1192 goto cleanup;
1193 if (ext4_xattr_check_block(bh)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04001194 EXT4_ERROR_INODE(inode, "bad block %llu",
1195 EXT4_I(inode)->i_file_acl);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001196 error = -EIO;
1197 goto cleanup;
1198 }
1199 base = BHDR(bh);
1200 first = BFIRST(bh);
1201 end = bh->b_data + bh->b_size;
1202 min_offs = end - base;
1203 free = ext4_xattr_free_space(first, &min_offs, base,
1204 &total_blk);
1205 if (free < new_extra_isize) {
1206 if (!tried_min_extra_isize && s_min_extra_isize) {
1207 tried_min_extra_isize++;
1208 new_extra_isize = s_min_extra_isize;
1209 brelse(bh);
1210 goto retry;
1211 }
1212 error = -1;
1213 goto cleanup;
1214 }
1215 } else {
1216 free = inode->i_sb->s_blocksize;
1217 }
1218
1219 while (new_extra_isize > 0) {
1220 size_t offs, size, entry_size;
1221 struct ext4_xattr_entry *small_entry = NULL;
1222 struct ext4_xattr_info i = {
1223 .value = NULL,
1224 .value_len = 0,
1225 };
1226 unsigned int total_size; /* EA entry size + value size */
1227 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1228 unsigned int min_total_size = ~0U;
1229
1230 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1231 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1232 if (!is || !bs) {
1233 error = -ENOMEM;
1234 goto cleanup;
1235 }
1236
1237 is->s.not_found = -ENODATA;
1238 bs->s.not_found = -ENODATA;
1239 is->iloc.bh = NULL;
1240 bs->bh = NULL;
1241
1242 last = IFIRST(header);
1243 /* Find the entry best suited to be pushed into EA block */
1244 entry = NULL;
1245 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1246 total_size =
1247 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1248 EXT4_XATTR_LEN(last->e_name_len);
1249 if (total_size <= free && total_size < min_total_size) {
1250 if (total_size < new_extra_isize) {
1251 small_entry = last;
1252 } else {
1253 entry = last;
1254 min_total_size = total_size;
1255 }
1256 }
1257 }
1258
1259 if (entry == NULL) {
1260 if (small_entry) {
1261 entry = small_entry;
1262 } else {
1263 if (!tried_min_extra_isize &&
1264 s_min_extra_isize) {
1265 tried_min_extra_isize++;
1266 new_extra_isize = s_min_extra_isize;
1267 goto retry;
1268 }
1269 error = -1;
1270 goto cleanup;
1271 }
1272 }
1273 offs = le16_to_cpu(entry->e_value_offs);
1274 size = le32_to_cpu(entry->e_value_size);
1275 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1276 i.name_index = entry->e_name_index,
1277 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1278 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1279 if (!buffer || !b_entry_name) {
1280 error = -ENOMEM;
1281 goto cleanup;
1282 }
1283 /* Save the entry name and the entry value */
1284 memcpy(buffer, (void *)IFIRST(header) + offs,
1285 EXT4_XATTR_SIZE(size));
1286 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1287 b_entry_name[entry->e_name_len] = '\0';
1288 i.name = b_entry_name;
1289
1290 error = ext4_get_inode_loc(inode, &is->iloc);
1291 if (error)
1292 goto cleanup;
1293
1294 error = ext4_xattr_ibody_find(inode, &i, is);
1295 if (error)
1296 goto cleanup;
1297
1298 /* Remove the chosen entry from the inode */
1299 error = ext4_xattr_ibody_set(handle, inode, &i, is);
Roel Kluin9aaab052010-02-15 14:26:16 -05001300 if (error)
1301 goto cleanup;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001302
1303 entry = IFIRST(header);
1304 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1305 shift_bytes = new_extra_isize;
1306 else
1307 shift_bytes = entry_size + size;
1308 /* Adjust the offsets and shift the remaining entries ahead */
1309 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1310 shift_bytes, (void *)raw_inode +
1311 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1312 (void *)header, total_ino - entry_size,
1313 inode->i_sb->s_blocksize);
1314
1315 extra_isize += shift_bytes;
1316 new_extra_isize -= shift_bytes;
1317 EXT4_I(inode)->i_extra_isize = extra_isize;
1318
1319 i.name = b_entry_name;
1320 i.value = buffer;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001321 i.value_len = size;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001322 error = ext4_xattr_block_find(inode, &i, bs);
1323 if (error)
1324 goto cleanup;
1325
1326 /* Add entry which was removed from the inode into the block */
1327 error = ext4_xattr_block_set(handle, inode, &i, bs);
1328 if (error)
1329 goto cleanup;
1330 kfree(b_entry_name);
1331 kfree(buffer);
Julia Lawalld3533d72009-12-23 07:52:31 -05001332 b_entry_name = NULL;
1333 buffer = NULL;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001334 brelse(is->iloc.bh);
1335 kfree(is);
1336 kfree(bs);
1337 }
1338 brelse(bh);
1339 up_write(&EXT4_I(inode)->xattr_sem);
1340 return 0;
1341
1342cleanup:
1343 kfree(b_entry_name);
1344 kfree(buffer);
1345 if (is)
1346 brelse(is->iloc.bh);
1347 kfree(is);
1348 kfree(bs);
1349 brelse(bh);
1350 up_write(&EXT4_I(inode)->xattr_sem);
1351 return error;
1352}
1353
1354
1355
1356/*
Mingming Cao617ba132006-10-11 01:20:53 -07001357 * ext4_xattr_delete_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001358 *
1359 * Free extended attribute resources associated with this inode. This
1360 * is called immediately before an inode is freed. We have exclusive
1361 * access to the inode.
1362 */
1363void
Mingming Cao617ba132006-10-11 01:20:53 -07001364ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001365{
1366 struct buffer_head *bh = NULL;
1367
Mingming Cao617ba132006-10-11 01:20:53 -07001368 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001369 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -07001370 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001371 if (!bh) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04001372 EXT4_ERROR_INODE(inode, "block %llu read error",
1373 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001374 goto cleanup;
1375 }
Mingming Cao617ba132006-10-11 01:20:53 -07001376 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001377 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04001378 EXT4_ERROR_INODE(inode, "bad block %llu",
1379 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001380 goto cleanup;
1381 }
Mingming Cao617ba132006-10-11 01:20:53 -07001382 ext4_xattr_release_block(handle, inode, bh);
1383 EXT4_I(inode)->i_file_acl = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001384
1385cleanup:
1386 brelse(bh);
1387}
1388
1389/*
Mingming Cao617ba132006-10-11 01:20:53 -07001390 * ext4_xattr_put_super()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001391 *
1392 * This is called when a file system is unmounted.
1393 */
1394void
Mingming Cao617ba132006-10-11 01:20:53 -07001395ext4_xattr_put_super(struct super_block *sb)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001396{
1397 mb_cache_shrink(sb->s_bdev);
1398}
1399
1400/*
Mingming Cao617ba132006-10-11 01:20:53 -07001401 * ext4_xattr_cache_insert()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001402 *
1403 * Create a new entry in the extended attribute cache, and insert
1404 * it unless such an entry is already in the cache.
1405 *
1406 * Returns 0, or a negative error number on failure.
1407 */
1408static void
Mingming Cao617ba132006-10-11 01:20:53 -07001409ext4_xattr_cache_insert(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001410{
1411 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1412 struct mb_cache_entry *ce;
1413 int error;
1414
Jan Kara335e92e2008-04-15 14:34:43 -07001415 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001416 if (!ce) {
1417 ea_bdebug(bh, "out of memory");
1418 return;
1419 }
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001420 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001421 if (error) {
1422 mb_cache_entry_free(ce);
1423 if (error == -EBUSY) {
1424 ea_bdebug(bh, "already in cache");
1425 error = 0;
1426 }
1427 } else {
1428 ea_bdebug(bh, "inserting [%x]", (int)hash);
1429 mb_cache_entry_release(ce);
1430 }
1431}
1432
1433/*
Mingming Cao617ba132006-10-11 01:20:53 -07001434 * ext4_xattr_cmp()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001435 *
1436 * Compare two extended attribute blocks for equality.
1437 *
1438 * Returns 0 if the blocks are equal, 1 if they differ, and
1439 * a negative error number on errors.
1440 */
1441static int
Mingming Cao617ba132006-10-11 01:20:53 -07001442ext4_xattr_cmp(struct ext4_xattr_header *header1,
1443 struct ext4_xattr_header *header2)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001444{
Mingming Cao617ba132006-10-11 01:20:53 -07001445 struct ext4_xattr_entry *entry1, *entry2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001446
1447 entry1 = ENTRY(header1+1);
1448 entry2 = ENTRY(header2+1);
1449 while (!IS_LAST_ENTRY(entry1)) {
1450 if (IS_LAST_ENTRY(entry2))
1451 return 1;
1452 if (entry1->e_hash != entry2->e_hash ||
1453 entry1->e_name_index != entry2->e_name_index ||
1454 entry1->e_name_len != entry2->e_name_len ||
1455 entry1->e_value_size != entry2->e_value_size ||
1456 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1457 return 1;
1458 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1459 return -EIO;
1460 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1461 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1462 le32_to_cpu(entry1->e_value_size)))
1463 return 1;
1464
Mingming Cao617ba132006-10-11 01:20:53 -07001465 entry1 = EXT4_XATTR_NEXT(entry1);
1466 entry2 = EXT4_XATTR_NEXT(entry2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001467 }
1468 if (!IS_LAST_ENTRY(entry2))
1469 return 1;
1470 return 0;
1471}
1472
1473/*
Mingming Cao617ba132006-10-11 01:20:53 -07001474 * ext4_xattr_cache_find()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001475 *
1476 * Find an identical extended attribute block.
1477 *
1478 * Returns a pointer to the block found, or NULL if such a block was
1479 * not found or an error occurred.
1480 */
1481static struct buffer_head *
Mingming Cao617ba132006-10-11 01:20:53 -07001482ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001483 struct mb_cache_entry **pce)
1484{
1485 __u32 hash = le32_to_cpu(header->h_hash);
1486 struct mb_cache_entry *ce;
1487
1488 if (!header->h_hash)
1489 return NULL; /* never share */
1490 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1491again:
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001492 ce = mb_cache_entry_find_first(ext4_xattr_cache, inode->i_sb->s_bdev,
1493 hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001494 while (ce) {
1495 struct buffer_head *bh;
1496
1497 if (IS_ERR(ce)) {
1498 if (PTR_ERR(ce) == -EAGAIN)
1499 goto again;
1500 break;
1501 }
1502 bh = sb_bread(inode->i_sb, ce->e_block);
1503 if (!bh) {
Theodore Ts'o24676da2010-05-16 21:00:00 -04001504 EXT4_ERROR_INODE(inode, "block %lu read error",
1505 (unsigned long) ce->e_block);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001506 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
Mingming Cao617ba132006-10-11 01:20:53 -07001507 EXT4_XATTR_REFCOUNT_MAX) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001508 ea_idebug(inode, "block %lu refcount %d>=%d",
1509 (unsigned long) ce->e_block,
1510 le32_to_cpu(BHDR(bh)->h_refcount),
Mingming Cao617ba132006-10-11 01:20:53 -07001511 EXT4_XATTR_REFCOUNT_MAX);
1512 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001513 *pce = ce;
1514 return bh;
1515 }
1516 brelse(bh);
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001517 ce = mb_cache_entry_find_next(ce, inode->i_sb->s_bdev, hash);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001518 }
1519 return NULL;
1520}
1521
1522#define NAME_HASH_SHIFT 5
1523#define VALUE_HASH_SHIFT 16
1524
1525/*
Mingming Cao617ba132006-10-11 01:20:53 -07001526 * ext4_xattr_hash_entry()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001527 *
1528 * Compute the hash of an extended attribute.
1529 */
Mingming Cao617ba132006-10-11 01:20:53 -07001530static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1531 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001532{
1533 __u32 hash = 0;
1534 char *name = entry->e_name;
1535 int n;
1536
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001537 for (n = 0; n < entry->e_name_len; n++) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001538 hash = (hash << NAME_HASH_SHIFT) ^
1539 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1540 *name++;
1541 }
1542
1543 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1544 __le32 *value = (__le32 *)((char *)header +
1545 le16_to_cpu(entry->e_value_offs));
1546 for (n = (le32_to_cpu(entry->e_value_size) +
Mingming Cao617ba132006-10-11 01:20:53 -07001547 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001548 hash = (hash << VALUE_HASH_SHIFT) ^
1549 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1550 le32_to_cpu(*value++);
1551 }
1552 }
1553 entry->e_hash = cpu_to_le32(hash);
1554}
1555
1556#undef NAME_HASH_SHIFT
1557#undef VALUE_HASH_SHIFT
1558
1559#define BLOCK_HASH_SHIFT 16
1560
1561/*
Mingming Cao617ba132006-10-11 01:20:53 -07001562 * ext4_xattr_rehash()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001563 *
1564 * Re-compute the extended attribute hash value after an entry has changed.
1565 */
Mingming Cao617ba132006-10-11 01:20:53 -07001566static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1567 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001568{
Mingming Cao617ba132006-10-11 01:20:53 -07001569 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001570 __u32 hash = 0;
1571
Mingming Cao617ba132006-10-11 01:20:53 -07001572 ext4_xattr_hash_entry(header, entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001573 here = ENTRY(header+1);
1574 while (!IS_LAST_ENTRY(here)) {
1575 if (!here->e_hash) {
1576 /* Block is not shared if an entry's hash value == 0 */
1577 hash = 0;
1578 break;
1579 }
1580 hash = (hash << BLOCK_HASH_SHIFT) ^
1581 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1582 le32_to_cpu(here->e_hash);
Mingming Cao617ba132006-10-11 01:20:53 -07001583 here = EXT4_XATTR_NEXT(here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001584 }
1585 header->h_hash = cpu_to_le32(hash);
1586}
1587
1588#undef BLOCK_HASH_SHIFT
1589
1590int __init
Theodore Ts'o5dabfc72010-10-27 21:30:14 -04001591ext4_init_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001592{
Andreas Gruenbacher2aec7c52010-07-19 18:19:41 +02001593 ext4_xattr_cache = mb_cache_create("ext4_xattr", 6);
Mingming Cao617ba132006-10-11 01:20:53 -07001594 if (!ext4_xattr_cache)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001595 return -ENOMEM;
1596 return 0;
1597}
1598
1599void
Theodore Ts'o5dabfc72010-10-27 21:30:14 -04001600ext4_exit_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001601{
Mingming Cao617ba132006-10-11 01:20:53 -07001602 if (ext4_xattr_cache)
1603 mb_cache_destroy(ext4_xattr_cache);
1604 ext4_xattr_cache = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001605}