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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>
Mingming Caodab291a2006-10-11 01:21:01 -070056#include <linux/ext4_jbd2.h>
Mingming Cao617ba132006-10-11 01:20:53 -070057#include <linux/ext4_fs.h>
Dave Kleikampac27a0e2006-10-11 01:20:50 -070058#include <linux/mbcache.h>
59#include <linux/quotaops.h>
60#include <linux/rwsem.h>
61#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 *);
Mingming Caod3a95d42008-04-17 10:38:59 -040095static int ext4_xattr_list(struct inode *inode, char *buffer,
96 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,
102#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
103 [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,
107#ifdef CONFIG_EXT4DEV_FS_SECURITY
108 [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,
115#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
116 &ext4_xattr_acl_access_handler,
117 &ext4_xattr_acl_default_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700118#endif
Mingming Cao617ba132006-10-11 01:20:53 -0700119#ifdef CONFIG_EXT4DEV_FS_SECURITY
120 &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{
Mingming Cao617ba132006-10-11 01:20:53 -0700143 return ext4_xattr_list(dentry->d_inode, 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)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -0400230bad_block: ext4_error(inode->i_sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700231 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700232 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
Mingming Cao617ba132006-10-11 01:20:53 -0700270 if (!(EXT4_I(inode)->i_state & 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
Mingming Cao617ba132006-10-11 01:20:53 -0700328ext4_xattr_list_entries(struct inode *inode, 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)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700334 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) {
338 size_t size = handler->list(inode, buffer, rest,
339 entry->e_name,
340 entry->e_name_len);
341 if (buffer) {
342 if (size > rest)
343 return -ERANGE;
344 buffer += size;
345 }
346 rest -= size;
347 }
348 }
349 return buffer_size - rest;
350}
351
352static int
Mingming Cao617ba132006-10-11 01:20:53 -0700353ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700354{
355 struct buffer_head *bh = NULL;
356 int error;
357
358 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
359 buffer, (long)buffer_size);
360
361 error = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700362 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700363 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700364 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
365 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700366 error = -EIO;
367 if (!bh)
368 goto cleanup;
369 ea_bdebug(bh, "b_count=%d, refcount=%d",
370 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700371 if (ext4_xattr_check_block(bh)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -0400372 ext4_error(inode->i_sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700373 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700374 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700375 error = -EIO;
376 goto cleanup;
377 }
Mingming Cao617ba132006-10-11 01:20:53 -0700378 ext4_xattr_cache_insert(bh);
379 error = ext4_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700380
381cleanup:
382 brelse(bh);
383
384 return error;
385}
386
387static int
Mingming Cao617ba132006-10-11 01:20:53 -0700388ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700389{
Mingming Cao617ba132006-10-11 01:20:53 -0700390 struct ext4_xattr_ibody_header *header;
391 struct ext4_inode *raw_inode;
392 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700393 void *end;
394 int error;
395
Mingming Cao617ba132006-10-11 01:20:53 -0700396 if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700398 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700399 if (error)
400 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700401 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700402 header = IHDR(inode, raw_inode);
Mingming Cao617ba132006-10-11 01:20:53 -0700403 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
404 error = ext4_xattr_check_names(IFIRST(header), end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700405 if (error)
406 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700407 error = ext4_xattr_list_entries(inode, IFIRST(header),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700408 buffer, buffer_size);
409
410cleanup:
411 brelse(iloc.bh);
412 return error;
413}
414
415/*
Mingming Cao617ba132006-10-11 01:20:53 -0700416 * ext4_xattr_list()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700417 *
418 * Copy a list of attribute names into the buffer
419 * provided, or compute the buffer size required.
420 * Buffer is NULL to compute the size of the buffer required.
421 *
422 * Returns a negative error number on failure, or the number of bytes
423 * used / required on success.
424 */
Mingming Caod3a95d42008-04-17 10:38:59 -0400425static int
Mingming Cao617ba132006-10-11 01:20:53 -0700426ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700427{
428 int i_error, b_error;
429
Mingming Cao617ba132006-10-11 01:20:53 -0700430 down_read(&EXT4_I(inode)->xattr_sem);
431 i_error = ext4_xattr_ibody_list(inode, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700432 if (i_error < 0) {
433 b_error = 0;
434 } else {
435 if (buffer) {
436 buffer += i_error;
437 buffer_size -= i_error;
438 }
Mingming Cao617ba132006-10-11 01:20:53 -0700439 b_error = ext4_xattr_block_list(inode, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700440 if (b_error < 0)
441 i_error = 0;
442 }
Mingming Cao617ba132006-10-11 01:20:53 -0700443 up_read(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700444 return i_error + b_error;
445}
446
447/*
Mingming Cao617ba132006-10-11 01:20:53 -0700448 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700449 * not set, set it.
450 */
Mingming Cao617ba132006-10-11 01:20:53 -0700451static void ext4_xattr_update_super_block(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700452 struct super_block *sb)
453{
Mingming Cao617ba132006-10-11 01:20:53 -0700454 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700455 return;
456
Mingming Cao617ba132006-10-11 01:20:53 -0700457 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
Andreas Gruenbachered2908f2006-12-06 20:36:16 -0800458 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459 sb->s_dirt = 1;
Mingming Cao617ba132006-10-11 01:20:53 -0700460 ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700461 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700462}
463
464/*
465 * Release the xattr block BH: If the reference count is > 1, decrement
466 * it; otherwise free the block.
467 */
468static void
Mingming Cao617ba132006-10-11 01:20:53 -0700469ext4_xattr_release_block(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700470 struct buffer_head *bh)
471{
472 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800473 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700474
Mingming Cao617ba132006-10-11 01:20:53 -0700475 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800476 error = ext4_journal_get_write_access(handle, bh);
477 if (error)
478 goto out;
479
480 lock_buffer(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700481 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
482 ea_bdebug(bh, "refcount now=0; freeing");
483 if (ce)
484 mb_cache_entry_free(ce);
Alex Tomasc9de5602008-01-29 00:19:52 -0500485 ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700486 get_bh(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700487 ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700488 } else {
Marcin Slusarze8546d02008-04-17 10:38:59 -0400489 le32_add_cpu(&BHDR(bh)->h_refcount, -1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800490 error = ext4_journal_dirty_metadata(handle, bh);
491 if (IS_SYNC(inode))
492 handle->h_sync = 1;
493 DQUOT_FREE_BLOCK(inode, 1);
494 ea_bdebug(bh, "refcount now=%d; releasing",
495 le32_to_cpu(BHDR(bh)->h_refcount));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700496 if (ce)
497 mb_cache_entry_release(ce);
498 }
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800499 unlock_buffer(bh);
500out:
501 ext4_std_error(inode->i_sb, error);
502 return;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700503}
504
Kalpak Shah6dd4ee72007-07-18 09:19:57 -0400505/*
506 * Find the available free space for EAs. This also returns the total number of
507 * bytes used by EA entries.
508 */
509static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
510 size_t *min_offs, void *base, int *total)
511{
512 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
513 *total += EXT4_XATTR_LEN(last->e_name_len);
514 if (!last->e_value_block && last->e_value_size) {
515 size_t offs = le16_to_cpu(last->e_value_offs);
516 if (offs < *min_offs)
517 *min_offs = offs;
518 }
519 }
520 return (*min_offs - ((void *)last - base) - sizeof(__u32));
521}
522
Mingming Cao617ba132006-10-11 01:20:53 -0700523struct ext4_xattr_info {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700524 int name_index;
525 const char *name;
526 const void *value;
527 size_t value_len;
528};
529
Mingming Cao617ba132006-10-11 01:20:53 -0700530struct ext4_xattr_search {
531 struct ext4_xattr_entry *first;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700532 void *base;
533 void *end;
Mingming Cao617ba132006-10-11 01:20:53 -0700534 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700535 int not_found;
536};
537
538static int
Mingming Cao617ba132006-10-11 01:20:53 -0700539ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700540{
Mingming Cao617ba132006-10-11 01:20:53 -0700541 struct ext4_xattr_entry *last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700542 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
543
544 /* Compute min_offs and last. */
545 last = s->first;
Mingming Cao617ba132006-10-11 01:20:53 -0700546 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700547 if (!last->e_value_block && last->e_value_size) {
548 size_t offs = le16_to_cpu(last->e_value_offs);
549 if (offs < min_offs)
550 min_offs = offs;
551 }
552 }
553 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
554 if (!s->not_found) {
555 if (!s->here->e_value_block && s->here->e_value_size) {
556 size_t size = le32_to_cpu(s->here->e_value_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700557 free += EXT4_XATTR_SIZE(size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700558 }
Mingming Cao617ba132006-10-11 01:20:53 -0700559 free += EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700560 }
561 if (i->value) {
Mingming Cao617ba132006-10-11 01:20:53 -0700562 if (free < EXT4_XATTR_SIZE(i->value_len) ||
563 free < EXT4_XATTR_LEN(name_len) +
564 EXT4_XATTR_SIZE(i->value_len))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700565 return -ENOSPC;
566 }
567
568 if (i->value && s->not_found) {
569 /* Insert the new name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700570 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700571 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
572 memmove((void *)s->here + size, s->here, rest);
573 memset(s->here, 0, size);
574 s->here->e_name_index = i->name_index;
575 s->here->e_name_len = name_len;
576 memcpy(s->here->e_name, i->name, name_len);
577 } else {
578 if (!s->here->e_value_block && s->here->e_value_size) {
579 void *first_val = s->base + min_offs;
580 size_t offs = le16_to_cpu(s->here->e_value_offs);
581 void *val = s->base + offs;
Mingming Cao617ba132006-10-11 01:20:53 -0700582 size_t size = EXT4_XATTR_SIZE(
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700583 le32_to_cpu(s->here->e_value_size));
584
Mingming Cao617ba132006-10-11 01:20:53 -0700585 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700586 /* The old and the new value have the same
587 size. Just replace. */
588 s->here->e_value_size =
589 cpu_to_le32(i->value_len);
Mingming Cao617ba132006-10-11 01:20:53 -0700590 memset(val + size - EXT4_XATTR_PAD, 0,
591 EXT4_XATTR_PAD); /* Clear pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700592 memcpy(val, i->value, i->value_len);
593 return 0;
594 }
595
596 /* Remove the old value. */
597 memmove(first_val + size, first_val, val - first_val);
598 memset(first_val, 0, size);
599 s->here->e_value_size = 0;
600 s->here->e_value_offs = 0;
601 min_offs += size;
602
603 /* Adjust all value offsets. */
604 last = s->first;
605 while (!IS_LAST_ENTRY(last)) {
606 size_t o = le16_to_cpu(last->e_value_offs);
607 if (!last->e_value_block &&
608 last->e_value_size && o < offs)
609 last->e_value_offs =
610 cpu_to_le16(o + size);
Mingming Cao617ba132006-10-11 01:20:53 -0700611 last = EXT4_XATTR_NEXT(last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700612 }
613 }
614 if (!i->value) {
615 /* Remove the old name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700616 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700617 last = ENTRY((void *)last - size);
618 memmove(s->here, (void *)s->here + size,
619 (void *)last - (void *)s->here + sizeof(__u32));
620 memset(last, 0, size);
621 }
622 }
623
624 if (i->value) {
625 /* Insert the new value. */
626 s->here->e_value_size = cpu_to_le32(i->value_len);
627 if (i->value_len) {
Mingming Cao617ba132006-10-11 01:20:53 -0700628 size_t size = EXT4_XATTR_SIZE(i->value_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700629 void *val = s->base + min_offs - size;
630 s->here->e_value_offs = cpu_to_le16(min_offs - size);
Mingming Cao617ba132006-10-11 01:20:53 -0700631 memset(val + size - EXT4_XATTR_PAD, 0,
632 EXT4_XATTR_PAD); /* Clear the pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700633 memcpy(val, i->value, i->value_len);
634 }
635 }
636 return 0;
637}
638
Mingming Cao617ba132006-10-11 01:20:53 -0700639struct ext4_xattr_block_find {
640 struct ext4_xattr_search s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700641 struct buffer_head *bh;
642};
643
644static int
Mingming Cao617ba132006-10-11 01:20:53 -0700645ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
646 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700647{
648 struct super_block *sb = inode->i_sb;
649 int error;
650
651 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
652 i->name_index, i->name, i->value, (long)i->value_len);
653
Mingming Cao617ba132006-10-11 01:20:53 -0700654 if (EXT4_I(inode)->i_file_acl) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700655 /* The inode already has an extended attribute block. */
Mingming Cao617ba132006-10-11 01:20:53 -0700656 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700657 error = -EIO;
658 if (!bs->bh)
659 goto cleanup;
660 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
661 atomic_read(&(bs->bh->b_count)),
662 le32_to_cpu(BHDR(bs->bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700663 if (ext4_xattr_check_block(bs->bh)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -0400664 ext4_error(sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700665 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700666 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700667 error = -EIO;
668 goto cleanup;
669 }
670 /* Find the named attribute. */
671 bs->s.base = BHDR(bs->bh);
672 bs->s.first = BFIRST(bs->bh);
673 bs->s.end = bs->bh->b_data + bs->bh->b_size;
674 bs->s.here = bs->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700675 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700676 i->name, bs->bh->b_size, 1);
677 if (error && error != -ENODATA)
678 goto cleanup;
679 bs->s.not_found = error;
680 }
681 error = 0;
682
683cleanup:
684 return error;
685}
686
687static int
Mingming Cao617ba132006-10-11 01:20:53 -0700688ext4_xattr_block_set(handle_t *handle, struct inode *inode,
689 struct ext4_xattr_info *i,
690 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700691{
692 struct super_block *sb = inode->i_sb;
693 struct buffer_head *new_bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700694 struct ext4_xattr_search *s = &bs->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700695 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800696 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700697
Mingming Cao617ba132006-10-11 01:20:53 -0700698#define header(x) ((struct ext4_xattr_header *)(x))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700699
700 if (i->value && i->value_len > sb->s_blocksize)
701 return -ENOSPC;
702 if (s->base) {
Mingming Cao617ba132006-10-11 01:20:53 -0700703 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700704 bs->bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800705 error = ext4_journal_get_write_access(handle, bs->bh);
706 if (error)
707 goto cleanup;
708 lock_buffer(bs->bh);
709
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700710 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
711 if (ce) {
712 mb_cache_entry_free(ce);
713 ce = NULL;
714 }
715 ea_bdebug(bs->bh, "modifying in-place");
Mingming Cao617ba132006-10-11 01:20:53 -0700716 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700717 if (!error) {
718 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700719 ext4_xattr_rehash(header(s->base),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700720 s->here);
Mingming Cao617ba132006-10-11 01:20:53 -0700721 ext4_xattr_cache_insert(bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700722 }
723 unlock_buffer(bs->bh);
724 if (error == -EIO)
725 goto bad_block;
726 if (!error)
Mingming Cao617ba132006-10-11 01:20:53 -0700727 error = ext4_journal_dirty_metadata(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700728 bs->bh);
729 if (error)
730 goto cleanup;
731 goto inserted;
732 } else {
733 int offset = (char *)s->here - bs->bh->b_data;
734
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800735 unlock_buffer(bs->bh);
736 jbd2_journal_release_buffer(handle, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700737 if (ce) {
738 mb_cache_entry_release(ce);
739 ce = NULL;
740 }
741 ea_bdebug(bs->bh, "cloning");
Josef Bacik216553c2008-04-29 22:02:02 -0400742 s->base = kmalloc(bs->bh->b_size, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700743 error = -ENOMEM;
744 if (s->base == NULL)
745 goto cleanup;
746 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
747 s->first = ENTRY(header(s->base)+1);
748 header(s->base)->h_refcount = cpu_to_le32(1);
749 s->here = ENTRY(s->base + offset);
750 s->end = s->base + bs->bh->b_size;
751 }
752 } else {
753 /* Allocate a buffer where we construct the new block. */
Josef Bacik216553c2008-04-29 22:02:02 -0400754 s->base = kzalloc(sb->s_blocksize, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700755 /* assert(header == s->base) */
756 error = -ENOMEM;
757 if (s->base == NULL)
758 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700759 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700760 header(s->base)->h_blocks = cpu_to_le32(1);
761 header(s->base)->h_refcount = cpu_to_le32(1);
762 s->first = ENTRY(header(s->base)+1);
763 s->here = ENTRY(header(s->base)+1);
764 s->end = s->base + sb->s_blocksize;
765 }
766
Mingming Cao617ba132006-10-11 01:20:53 -0700767 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700768 if (error == -EIO)
769 goto bad_block;
770 if (error)
771 goto cleanup;
772 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700773 ext4_xattr_rehash(header(s->base), s->here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700774
775inserted:
776 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700777 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700778 if (new_bh) {
779 /* We found an identical block in the cache. */
780 if (new_bh == bs->bh)
781 ea_bdebug(new_bh, "keeping");
782 else {
783 /* The old block is released after updating
784 the inode. */
785 error = -EDQUOT;
786 if (DQUOT_ALLOC_BLOCK(inode, 1))
787 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700788 error = ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700789 new_bh);
790 if (error)
791 goto cleanup_dquot;
792 lock_buffer(new_bh);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400793 le32_add_cpu(&BHDR(new_bh)->h_refcount, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700794 ea_bdebug(new_bh, "reusing; refcount now=%d",
795 le32_to_cpu(BHDR(new_bh)->h_refcount));
796 unlock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700797 error = ext4_journal_dirty_metadata(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700798 new_bh);
799 if (error)
800 goto cleanup_dquot;
801 }
802 mb_cache_entry_release(ce);
803 ce = NULL;
804 } else if (bs->bh && s->base == bs->bh->b_data) {
805 /* We were modifying this block in-place. */
806 ea_bdebug(bs->bh, "keeping this block");
807 new_bh = bs->bh;
808 get_bh(new_bh);
809 } else {
810 /* We need to allocate a new block */
Akinobu Mitad00a6d72008-04-17 10:38:59 -0400811 ext4_fsblk_t goal = ext4_group_first_block_no(sb,
812 EXT4_I(inode)->i_block_group);
Mingming Cao617ba132006-10-11 01:20:53 -0700813 ext4_fsblk_t block = ext4_new_block(handle, inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700814 goal, &error);
815 if (error)
816 goto cleanup;
817 ea_idebug(inode, "creating block %d", block);
818
819 new_bh = sb_getblk(sb, block);
820 if (!new_bh) {
821getblk_failed:
Alex Tomasc9de5602008-01-29 00:19:52 -0500822 ext4_free_blocks(handle, inode, block, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700823 error = -EIO;
824 goto cleanup;
825 }
826 lock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700827 error = ext4_journal_get_create_access(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700828 if (error) {
829 unlock_buffer(new_bh);
830 goto getblk_failed;
831 }
832 memcpy(new_bh->b_data, s->base, new_bh->b_size);
833 set_buffer_uptodate(new_bh);
834 unlock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700835 ext4_xattr_cache_insert(new_bh);
836 error = ext4_journal_dirty_metadata(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700837 if (error)
838 goto cleanup;
839 }
840 }
841
842 /* Update the inode. */
Mingming Cao617ba132006-10-11 01:20:53 -0700843 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700844
845 /* Drop the previous xattr block. */
846 if (bs->bh && bs->bh != new_bh)
Mingming Cao617ba132006-10-11 01:20:53 -0700847 ext4_xattr_release_block(handle, inode, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700848 error = 0;
849
850cleanup:
851 if (ce)
852 mb_cache_entry_release(ce);
853 brelse(new_bh);
854 if (!(bs->bh && s->base == bs->bh->b_data))
855 kfree(s->base);
856
857 return error;
858
859cleanup_dquot:
860 DQUOT_FREE_BLOCK(inode, 1);
861 goto cleanup;
862
863bad_block:
Harvey Harrison46e665e2008-04-17 10:38:59 -0400864 ext4_error(inode->i_sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700865 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700866 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700867 goto cleanup;
868
869#undef header
870}
871
Mingming Cao617ba132006-10-11 01:20:53 -0700872struct ext4_xattr_ibody_find {
873 struct ext4_xattr_search s;
874 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700875};
876
877static int
Mingming Cao617ba132006-10-11 01:20:53 -0700878ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
879 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700880{
Mingming Cao617ba132006-10-11 01:20:53 -0700881 struct ext4_xattr_ibody_header *header;
882 struct ext4_inode *raw_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700883 int error;
884
Mingming Cao617ba132006-10-11 01:20:53 -0700885 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700886 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700887 raw_inode = ext4_raw_inode(&is->iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700888 header = IHDR(inode, raw_inode);
889 is->s.base = is->s.first = IFIRST(header);
890 is->s.here = is->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700891 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
892 if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
893 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700894 if (error)
895 return error;
896 /* Find the named attribute. */
Mingming Cao617ba132006-10-11 01:20:53 -0700897 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700898 i->name, is->s.end -
899 (void *)is->s.base, 0);
900 if (error && error != -ENODATA)
901 return error;
902 is->s.not_found = error;
903 }
904 return 0;
905}
906
907static int
Mingming Cao617ba132006-10-11 01:20:53 -0700908ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
909 struct ext4_xattr_info *i,
910 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700911{
Mingming Cao617ba132006-10-11 01:20:53 -0700912 struct ext4_xattr_ibody_header *header;
913 struct ext4_xattr_search *s = &is->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700914 int error;
915
Mingming Cao617ba132006-10-11 01:20:53 -0700916 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700917 return -ENOSPC;
Mingming Cao617ba132006-10-11 01:20:53 -0700918 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700919 if (error)
920 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700921 header = IHDR(inode, ext4_raw_inode(&is->iloc));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700922 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700923 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
924 EXT4_I(inode)->i_state |= EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700925 } else {
926 header->h_magic = cpu_to_le32(0);
Mingming Cao617ba132006-10-11 01:20:53 -0700927 EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700928 }
929 return 0;
930}
931
932/*
Mingming Cao617ba132006-10-11 01:20:53 -0700933 * ext4_xattr_set_handle()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700934 *
935 * Create, replace or remove an extended attribute for this inode. Buffer
936 * is NULL to remove an existing extended attribute, and non-NULL to
937 * either replace an existing extended attribute, or create a new extended
938 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
939 * specify that an extended attribute must exist and must not exist
940 * previous to the call, respectively.
941 *
942 * Returns 0, or a negative error number on failure.
943 */
944int
Mingming Cao617ba132006-10-11 01:20:53 -0700945ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700946 const char *name, const void *value, size_t value_len,
947 int flags)
948{
Mingming Cao617ba132006-10-11 01:20:53 -0700949 struct ext4_xattr_info i = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700950 .name_index = name_index,
951 .name = name,
952 .value = value,
953 .value_len = value_len,
954
955 };
Mingming Cao617ba132006-10-11 01:20:53 -0700956 struct ext4_xattr_ibody_find is = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700957 .s = { .not_found = -ENODATA, },
958 };
Mingming Cao617ba132006-10-11 01:20:53 -0700959 struct ext4_xattr_block_find bs = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700960 .s = { .not_found = -ENODATA, },
961 };
962 int error;
963
964 if (!name)
965 return -EINVAL;
966 if (strlen(name) > 255)
967 return -ERANGE;
Mingming Cao617ba132006-10-11 01:20:53 -0700968 down_write(&EXT4_I(inode)->xattr_sem);
969 error = ext4_get_inode_loc(inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700970 if (error)
971 goto cleanup;
972
Mingming Cao617ba132006-10-11 01:20:53 -0700973 if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) {
974 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
975 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
976 EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700977 }
978
Mingming Cao617ba132006-10-11 01:20:53 -0700979 error = ext4_xattr_ibody_find(inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700980 if (error)
981 goto cleanup;
982 if (is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -0700983 error = ext4_xattr_block_find(inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700984 if (error)
985 goto cleanup;
986 if (is.s.not_found && bs.s.not_found) {
987 error = -ENODATA;
988 if (flags & XATTR_REPLACE)
989 goto cleanup;
990 error = 0;
991 if (!value)
992 goto cleanup;
993 } else {
994 error = -EEXIST;
995 if (flags & XATTR_CREATE)
996 goto cleanup;
997 }
Mingming Cao617ba132006-10-11 01:20:53 -0700998 error = ext4_journal_get_write_access(handle, is.iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700999 if (error)
1000 goto cleanup;
1001 if (!value) {
1002 if (!is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001003 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001004 else if (!bs.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001005 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001006 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07001007 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001008 if (!error && !bs.s.not_found) {
1009 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001010 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001011 } else if (error == -ENOSPC) {
Mingming Cao617ba132006-10-11 01:20:53 -07001012 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001013 if (error)
1014 goto cleanup;
1015 if (!is.s.not_found) {
1016 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001017 error = ext4_xattr_ibody_set(handle, inode, &i,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001018 &is);
1019 }
1020 }
1021 }
1022 if (!error) {
Mingming Cao617ba132006-10-11 01:20:53 -07001023 ext4_xattr_update_super_block(handle, inode->i_sb);
Kalpak Shahef7f3832007-07-18 09:15:20 -04001024 inode->i_ctime = ext4_current_time(inode);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001025 if (!value)
1026 EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
Mingming Cao617ba132006-10-11 01:20:53 -07001027 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001028 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001029 * The bh is consumed by ext4_mark_iloc_dirty, even with
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001030 * error != 0.
1031 */
1032 is.iloc.bh = NULL;
1033 if (IS_SYNC(inode))
1034 handle->h_sync = 1;
1035 }
1036
1037cleanup:
1038 brelse(is.iloc.bh);
1039 brelse(bs.bh);
Mingming Cao617ba132006-10-11 01:20:53 -07001040 up_write(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001041 return error;
1042}
1043
1044/*
Mingming Cao617ba132006-10-11 01:20:53 -07001045 * ext4_xattr_set()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001046 *
Mingming Cao617ba132006-10-11 01:20:53 -07001047 * Like ext4_xattr_set_handle, but start from an inode. This extended
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001048 * attribute modification is a filesystem transaction by itself.
1049 *
1050 * Returns 0, or a negative error number on failure.
1051 */
1052int
Mingming Cao617ba132006-10-11 01:20:53 -07001053ext4_xattr_set(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001054 const void *value, size_t value_len, int flags)
1055{
1056 handle_t *handle;
1057 int error, retries = 0;
1058
1059retry:
Mingming Cao617ba132006-10-11 01:20:53 -07001060 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001061 if (IS_ERR(handle)) {
1062 error = PTR_ERR(handle);
1063 } else {
1064 int error2;
1065
Mingming Cao617ba132006-10-11 01:20:53 -07001066 error = ext4_xattr_set_handle(handle, inode, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001067 value, value_len, flags);
Mingming Cao617ba132006-10-11 01:20:53 -07001068 error2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001069 if (error == -ENOSPC &&
Mingming Cao617ba132006-10-11 01:20:53 -07001070 ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001071 goto retry;
1072 if (error == 0)
1073 error = error2;
1074 }
1075
1076 return error;
1077}
1078
1079/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001080 * Shift the EA entries in the inode to create space for the increased
1081 * i_extra_isize.
1082 */
1083static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1084 int value_offs_shift, void *to,
1085 void *from, size_t n, int blocksize)
1086{
1087 struct ext4_xattr_entry *last = entry;
1088 int new_offs;
1089
1090 /* Adjust the value offsets of the entries */
1091 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1092 if (!last->e_value_block && last->e_value_size) {
1093 new_offs = le16_to_cpu(last->e_value_offs) +
1094 value_offs_shift;
1095 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1096 > blocksize);
1097 last->e_value_offs = cpu_to_le16(new_offs);
1098 }
1099 }
1100 /* Shift the entries by n bytes */
1101 memmove(to, from, n);
1102}
1103
1104/*
1105 * Expand an inode by new_extra_isize bytes when EAs are present.
1106 * Returns 0 on success or negative error number on failure.
1107 */
1108int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1109 struct ext4_inode *raw_inode, handle_t *handle)
1110{
1111 struct ext4_xattr_ibody_header *header;
1112 struct ext4_xattr_entry *entry, *last, *first;
1113 struct buffer_head *bh = NULL;
1114 struct ext4_xattr_ibody_find *is = NULL;
1115 struct ext4_xattr_block_find *bs = NULL;
1116 char *buffer = NULL, *b_entry_name = NULL;
1117 size_t min_offs, free;
1118 int total_ino, total_blk;
1119 void *base, *start, *end;
1120 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001121 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 -04001122
1123 down_write(&EXT4_I(inode)->xattr_sem);
1124retry:
1125 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1126 up_write(&EXT4_I(inode)->xattr_sem);
1127 return 0;
1128 }
1129
1130 header = IHDR(inode, raw_inode);
1131 entry = IFIRST(header);
1132
1133 /*
1134 * Check if enough free space is available in the inode to shift the
1135 * entries ahead by new_extra_isize.
1136 */
1137
1138 base = start = entry;
1139 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1140 min_offs = end - base;
1141 last = entry;
1142 total_ino = sizeof(struct ext4_xattr_ibody_header);
1143
1144 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1145 if (free >= new_extra_isize) {
1146 entry = IFIRST(header);
1147 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1148 - new_extra_isize, (void *)raw_inode +
1149 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1150 (void *)header, total_ino,
1151 inode->i_sb->s_blocksize);
1152 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1153 error = 0;
1154 goto cleanup;
1155 }
1156
1157 /*
1158 * Enough free space isn't available in the inode, check if
1159 * EA block can hold new_extra_isize bytes.
1160 */
1161 if (EXT4_I(inode)->i_file_acl) {
1162 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1163 error = -EIO;
1164 if (!bh)
1165 goto cleanup;
1166 if (ext4_xattr_check_block(bh)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001167 ext4_error(inode->i_sb, __func__,
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001168 "inode %lu: bad block %llu", inode->i_ino,
1169 EXT4_I(inode)->i_file_acl);
1170 error = -EIO;
1171 goto cleanup;
1172 }
1173 base = BHDR(bh);
1174 first = BFIRST(bh);
1175 end = bh->b_data + bh->b_size;
1176 min_offs = end - base;
1177 free = ext4_xattr_free_space(first, &min_offs, base,
1178 &total_blk);
1179 if (free < new_extra_isize) {
1180 if (!tried_min_extra_isize && s_min_extra_isize) {
1181 tried_min_extra_isize++;
1182 new_extra_isize = s_min_extra_isize;
1183 brelse(bh);
1184 goto retry;
1185 }
1186 error = -1;
1187 goto cleanup;
1188 }
1189 } else {
1190 free = inode->i_sb->s_blocksize;
1191 }
1192
1193 while (new_extra_isize > 0) {
1194 size_t offs, size, entry_size;
1195 struct ext4_xattr_entry *small_entry = NULL;
1196 struct ext4_xattr_info i = {
1197 .value = NULL,
1198 .value_len = 0,
1199 };
1200 unsigned int total_size; /* EA entry size + value size */
1201 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1202 unsigned int min_total_size = ~0U;
1203
1204 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1205 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1206 if (!is || !bs) {
1207 error = -ENOMEM;
1208 goto cleanup;
1209 }
1210
1211 is->s.not_found = -ENODATA;
1212 bs->s.not_found = -ENODATA;
1213 is->iloc.bh = NULL;
1214 bs->bh = NULL;
1215
1216 last = IFIRST(header);
1217 /* Find the entry best suited to be pushed into EA block */
1218 entry = NULL;
1219 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1220 total_size =
1221 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1222 EXT4_XATTR_LEN(last->e_name_len);
1223 if (total_size <= free && total_size < min_total_size) {
1224 if (total_size < new_extra_isize) {
1225 small_entry = last;
1226 } else {
1227 entry = last;
1228 min_total_size = total_size;
1229 }
1230 }
1231 }
1232
1233 if (entry == NULL) {
1234 if (small_entry) {
1235 entry = small_entry;
1236 } else {
1237 if (!tried_min_extra_isize &&
1238 s_min_extra_isize) {
1239 tried_min_extra_isize++;
1240 new_extra_isize = s_min_extra_isize;
1241 goto retry;
1242 }
1243 error = -1;
1244 goto cleanup;
1245 }
1246 }
1247 offs = le16_to_cpu(entry->e_value_offs);
1248 size = le32_to_cpu(entry->e_value_size);
1249 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1250 i.name_index = entry->e_name_index,
1251 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1252 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1253 if (!buffer || !b_entry_name) {
1254 error = -ENOMEM;
1255 goto cleanup;
1256 }
1257 /* Save the entry name and the entry value */
1258 memcpy(buffer, (void *)IFIRST(header) + offs,
1259 EXT4_XATTR_SIZE(size));
1260 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1261 b_entry_name[entry->e_name_len] = '\0';
1262 i.name = b_entry_name;
1263
1264 error = ext4_get_inode_loc(inode, &is->iloc);
1265 if (error)
1266 goto cleanup;
1267
1268 error = ext4_xattr_ibody_find(inode, &i, is);
1269 if (error)
1270 goto cleanup;
1271
1272 /* Remove the chosen entry from the inode */
1273 error = ext4_xattr_ibody_set(handle, inode, &i, is);
1274
1275 entry = IFIRST(header);
1276 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1277 shift_bytes = new_extra_isize;
1278 else
1279 shift_bytes = entry_size + size;
1280 /* Adjust the offsets and shift the remaining entries ahead */
1281 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1282 shift_bytes, (void *)raw_inode +
1283 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1284 (void *)header, total_ino - entry_size,
1285 inode->i_sb->s_blocksize);
1286
1287 extra_isize += shift_bytes;
1288 new_extra_isize -= shift_bytes;
1289 EXT4_I(inode)->i_extra_isize = extra_isize;
1290
1291 i.name = b_entry_name;
1292 i.value = buffer;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001293 i.value_len = size;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001294 error = ext4_xattr_block_find(inode, &i, bs);
1295 if (error)
1296 goto cleanup;
1297
1298 /* Add entry which was removed from the inode into the block */
1299 error = ext4_xattr_block_set(handle, inode, &i, bs);
1300 if (error)
1301 goto cleanup;
1302 kfree(b_entry_name);
1303 kfree(buffer);
1304 brelse(is->iloc.bh);
1305 kfree(is);
1306 kfree(bs);
1307 }
1308 brelse(bh);
1309 up_write(&EXT4_I(inode)->xattr_sem);
1310 return 0;
1311
1312cleanup:
1313 kfree(b_entry_name);
1314 kfree(buffer);
1315 if (is)
1316 brelse(is->iloc.bh);
1317 kfree(is);
1318 kfree(bs);
1319 brelse(bh);
1320 up_write(&EXT4_I(inode)->xattr_sem);
1321 return error;
1322}
1323
1324
1325
1326/*
Mingming Cao617ba132006-10-11 01:20:53 -07001327 * ext4_xattr_delete_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001328 *
1329 * Free extended attribute resources associated with this inode. This
1330 * is called immediately before an inode is freed. We have exclusive
1331 * access to the inode.
1332 */
1333void
Mingming Cao617ba132006-10-11 01:20:53 -07001334ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001335{
1336 struct buffer_head *bh = NULL;
1337
Mingming Cao617ba132006-10-11 01:20:53 -07001338 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001339 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -07001340 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001341 if (!bh) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001342 ext4_error(inode->i_sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -07001343 "inode %lu: block %llu read error", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -07001344 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001345 goto cleanup;
1346 }
Mingming Cao617ba132006-10-11 01:20:53 -07001347 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001348 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001349 ext4_error(inode->i_sb, __func__,
Mingming Cao2ae02102006-10-11 01:21:11 -07001350 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -07001351 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001352 goto cleanup;
1353 }
Mingming Cao617ba132006-10-11 01:20:53 -07001354 ext4_xattr_release_block(handle, inode, bh);
1355 EXT4_I(inode)->i_file_acl = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001356
1357cleanup:
1358 brelse(bh);
1359}
1360
1361/*
Mingming Cao617ba132006-10-11 01:20:53 -07001362 * ext4_xattr_put_super()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001363 *
1364 * This is called when a file system is unmounted.
1365 */
1366void
Mingming Cao617ba132006-10-11 01:20:53 -07001367ext4_xattr_put_super(struct super_block *sb)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001368{
1369 mb_cache_shrink(sb->s_bdev);
1370}
1371
1372/*
Mingming Cao617ba132006-10-11 01:20:53 -07001373 * ext4_xattr_cache_insert()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001374 *
1375 * Create a new entry in the extended attribute cache, and insert
1376 * it unless such an entry is already in the cache.
1377 *
1378 * Returns 0, or a negative error number on failure.
1379 */
1380static void
Mingming Cao617ba132006-10-11 01:20:53 -07001381ext4_xattr_cache_insert(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001382{
1383 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1384 struct mb_cache_entry *ce;
1385 int error;
1386
Jan Kara335e92e2008-04-15 14:34:43 -07001387 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001388 if (!ce) {
1389 ea_bdebug(bh, "out of memory");
1390 return;
1391 }
1392 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash);
1393 if (error) {
1394 mb_cache_entry_free(ce);
1395 if (error == -EBUSY) {
1396 ea_bdebug(bh, "already in cache");
1397 error = 0;
1398 }
1399 } else {
1400 ea_bdebug(bh, "inserting [%x]", (int)hash);
1401 mb_cache_entry_release(ce);
1402 }
1403}
1404
1405/*
Mingming Cao617ba132006-10-11 01:20:53 -07001406 * ext4_xattr_cmp()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001407 *
1408 * Compare two extended attribute blocks for equality.
1409 *
1410 * Returns 0 if the blocks are equal, 1 if they differ, and
1411 * a negative error number on errors.
1412 */
1413static int
Mingming Cao617ba132006-10-11 01:20:53 -07001414ext4_xattr_cmp(struct ext4_xattr_header *header1,
1415 struct ext4_xattr_header *header2)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001416{
Mingming Cao617ba132006-10-11 01:20:53 -07001417 struct ext4_xattr_entry *entry1, *entry2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001418
1419 entry1 = ENTRY(header1+1);
1420 entry2 = ENTRY(header2+1);
1421 while (!IS_LAST_ENTRY(entry1)) {
1422 if (IS_LAST_ENTRY(entry2))
1423 return 1;
1424 if (entry1->e_hash != entry2->e_hash ||
1425 entry1->e_name_index != entry2->e_name_index ||
1426 entry1->e_name_len != entry2->e_name_len ||
1427 entry1->e_value_size != entry2->e_value_size ||
1428 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1429 return 1;
1430 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1431 return -EIO;
1432 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1433 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1434 le32_to_cpu(entry1->e_value_size)))
1435 return 1;
1436
Mingming Cao617ba132006-10-11 01:20:53 -07001437 entry1 = EXT4_XATTR_NEXT(entry1);
1438 entry2 = EXT4_XATTR_NEXT(entry2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001439 }
1440 if (!IS_LAST_ENTRY(entry2))
1441 return 1;
1442 return 0;
1443}
1444
1445/*
Mingming Cao617ba132006-10-11 01:20:53 -07001446 * ext4_xattr_cache_find()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001447 *
1448 * Find an identical extended attribute block.
1449 *
1450 * Returns a pointer to the block found, or NULL if such a block was
1451 * not found or an error occurred.
1452 */
1453static struct buffer_head *
Mingming Cao617ba132006-10-11 01:20:53 -07001454ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001455 struct mb_cache_entry **pce)
1456{
1457 __u32 hash = le32_to_cpu(header->h_hash);
1458 struct mb_cache_entry *ce;
1459
1460 if (!header->h_hash)
1461 return NULL; /* never share */
1462 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1463again:
Mingming Cao617ba132006-10-11 01:20:53 -07001464 ce = mb_cache_entry_find_first(ext4_xattr_cache, 0,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001465 inode->i_sb->s_bdev, hash);
1466 while (ce) {
1467 struct buffer_head *bh;
1468
1469 if (IS_ERR(ce)) {
1470 if (PTR_ERR(ce) == -EAGAIN)
1471 goto again;
1472 break;
1473 }
1474 bh = sb_bread(inode->i_sb, ce->e_block);
1475 if (!bh) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001476 ext4_error(inode->i_sb, __func__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001477 "inode %lu: block %lu read error",
1478 inode->i_ino, (unsigned long) ce->e_block);
1479 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
Mingming Cao617ba132006-10-11 01:20:53 -07001480 EXT4_XATTR_REFCOUNT_MAX) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001481 ea_idebug(inode, "block %lu refcount %d>=%d",
1482 (unsigned long) ce->e_block,
1483 le32_to_cpu(BHDR(bh)->h_refcount),
Mingming Cao617ba132006-10-11 01:20:53 -07001484 EXT4_XATTR_REFCOUNT_MAX);
1485 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001486 *pce = ce;
1487 return bh;
1488 }
1489 brelse(bh);
1490 ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash);
1491 }
1492 return NULL;
1493}
1494
1495#define NAME_HASH_SHIFT 5
1496#define VALUE_HASH_SHIFT 16
1497
1498/*
Mingming Cao617ba132006-10-11 01:20:53 -07001499 * ext4_xattr_hash_entry()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001500 *
1501 * Compute the hash of an extended attribute.
1502 */
Mingming Cao617ba132006-10-11 01:20:53 -07001503static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1504 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001505{
1506 __u32 hash = 0;
1507 char *name = entry->e_name;
1508 int n;
1509
1510 for (n=0; n < entry->e_name_len; n++) {
1511 hash = (hash << NAME_HASH_SHIFT) ^
1512 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1513 *name++;
1514 }
1515
1516 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1517 __le32 *value = (__le32 *)((char *)header +
1518 le16_to_cpu(entry->e_value_offs));
1519 for (n = (le32_to_cpu(entry->e_value_size) +
Mingming Cao617ba132006-10-11 01:20:53 -07001520 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001521 hash = (hash << VALUE_HASH_SHIFT) ^
1522 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1523 le32_to_cpu(*value++);
1524 }
1525 }
1526 entry->e_hash = cpu_to_le32(hash);
1527}
1528
1529#undef NAME_HASH_SHIFT
1530#undef VALUE_HASH_SHIFT
1531
1532#define BLOCK_HASH_SHIFT 16
1533
1534/*
Mingming Cao617ba132006-10-11 01:20:53 -07001535 * ext4_xattr_rehash()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001536 *
1537 * Re-compute the extended attribute hash value after an entry has changed.
1538 */
Mingming Cao617ba132006-10-11 01:20:53 -07001539static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1540 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001541{
Mingming Cao617ba132006-10-11 01:20:53 -07001542 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001543 __u32 hash = 0;
1544
Mingming Cao617ba132006-10-11 01:20:53 -07001545 ext4_xattr_hash_entry(header, entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001546 here = ENTRY(header+1);
1547 while (!IS_LAST_ENTRY(here)) {
1548 if (!here->e_hash) {
1549 /* Block is not shared if an entry's hash value == 0 */
1550 hash = 0;
1551 break;
1552 }
1553 hash = (hash << BLOCK_HASH_SHIFT) ^
1554 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1555 le32_to_cpu(here->e_hash);
Mingming Cao617ba132006-10-11 01:20:53 -07001556 here = EXT4_XATTR_NEXT(here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001557 }
1558 header->h_hash = cpu_to_le32(hash);
1559}
1560
1561#undef BLOCK_HASH_SHIFT
1562
1563int __init
Mingming Cao617ba132006-10-11 01:20:53 -07001564init_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001565{
Mingming Cao617ba132006-10-11 01:20:53 -07001566 ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001567 sizeof(struct mb_cache_entry) +
1568 sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6);
Mingming Cao617ba132006-10-11 01:20:53 -07001569 if (!ext4_xattr_cache)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001570 return -ENOMEM;
1571 return 0;
1572}
1573
1574void
Mingming Cao617ba132006-10-11 01:20:53 -07001575exit_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001576{
Mingming Cao617ba132006-10-11 01:20:53 -07001577 if (ext4_xattr_cache)
1578 mb_cache_destroy(ext4_xattr_cache);
1579 ext4_xattr_cache = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001580}