blob: e9054c1c7d9366ce36f1d140b125c5db8915cd15 [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>
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 *);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095
Mingming Cao617ba132006-10-11 01:20:53 -070096static struct mb_cache *ext4_xattr_cache;
Dave Kleikampac27a0e2006-10-11 01:20:50 -070097
Mingming Cao617ba132006-10-11 01:20:53 -070098static struct xattr_handler *ext4_xattr_handler_map[] = {
99 [EXT4_XATTR_INDEX_USER] = &ext4_xattr_user_handler,
100#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
101 [EXT4_XATTR_INDEX_POSIX_ACL_ACCESS] = &ext4_xattr_acl_access_handler,
102 [EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT] = &ext4_xattr_acl_default_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103#endif
Mingming Cao617ba132006-10-11 01:20:53 -0700104 [EXT4_XATTR_INDEX_TRUSTED] = &ext4_xattr_trusted_handler,
105#ifdef CONFIG_EXT4DEV_FS_SECURITY
106 [EXT4_XATTR_INDEX_SECURITY] = &ext4_xattr_security_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700107#endif
108};
109
Mingming Cao617ba132006-10-11 01:20:53 -0700110struct xattr_handler *ext4_xattr_handlers[] = {
111 &ext4_xattr_user_handler,
112 &ext4_xattr_trusted_handler,
113#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
114 &ext4_xattr_acl_access_handler,
115 &ext4_xattr_acl_default_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700116#endif
Mingming Cao617ba132006-10-11 01:20:53 -0700117#ifdef CONFIG_EXT4DEV_FS_SECURITY
118 &ext4_xattr_security_handler,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700119#endif
120 NULL
121};
122
123static inline struct xattr_handler *
Mingming Cao617ba132006-10-11 01:20:53 -0700124ext4_xattr_handler(int name_index)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700125{
126 struct xattr_handler *handler = NULL;
127
Mingming Cao617ba132006-10-11 01:20:53 -0700128 if (name_index > 0 && name_index < ARRAY_SIZE(ext4_xattr_handler_map))
129 handler = ext4_xattr_handler_map[name_index];
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700130 return handler;
131}
132
133/*
134 * Inode operation listxattr()
135 *
136 * dentry->d_inode->i_mutex: don't care
137 */
138ssize_t
Mingming Cao617ba132006-10-11 01:20:53 -0700139ext4_listxattr(struct dentry *dentry, char *buffer, size_t size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700140{
Mingming Cao617ba132006-10-11 01:20:53 -0700141 return ext4_xattr_list(dentry->d_inode, buffer, size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700142}
143
144static int
Mingming Cao617ba132006-10-11 01:20:53 -0700145ext4_xattr_check_names(struct ext4_xattr_entry *entry, void *end)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700146{
147 while (!IS_LAST_ENTRY(entry)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700148 struct ext4_xattr_entry *next = EXT4_XATTR_NEXT(entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700149 if ((void *)next >= end)
150 return -EIO;
151 entry = next;
152 }
153 return 0;
154}
155
156static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700157ext4_xattr_check_block(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700158{
159 int error;
160
Mingming Cao617ba132006-10-11 01:20:53 -0700161 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700162 BHDR(bh)->h_blocks != cpu_to_le32(1))
163 return -EIO;
Mingming Cao617ba132006-10-11 01:20:53 -0700164 error = ext4_xattr_check_names(BFIRST(bh), bh->b_data + bh->b_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700165 return error;
166}
167
168static inline int
Mingming Cao617ba132006-10-11 01:20:53 -0700169ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700170{
171 size_t value_size = le32_to_cpu(entry->e_value_size);
172
173 if (entry->e_value_block != 0 || value_size > size ||
174 le16_to_cpu(entry->e_value_offs) + value_size > size)
175 return -EIO;
176 return 0;
177}
178
179static int
Mingming Cao617ba132006-10-11 01:20:53 -0700180ext4_xattr_find_entry(struct ext4_xattr_entry **pentry, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700181 const char *name, size_t size, int sorted)
182{
Mingming Cao617ba132006-10-11 01:20:53 -0700183 struct ext4_xattr_entry *entry;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700184 size_t name_len;
185 int cmp = 1;
186
187 if (name == NULL)
188 return -EINVAL;
189 name_len = strlen(name);
190 entry = *pentry;
Mingming Cao617ba132006-10-11 01:20:53 -0700191 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700192 cmp = name_index - entry->e_name_index;
193 if (!cmp)
194 cmp = name_len - entry->e_name_len;
195 if (!cmp)
196 cmp = memcmp(name, entry->e_name, name_len);
197 if (cmp <= 0 && (sorted || cmp == 0))
198 break;
199 }
200 *pentry = entry;
Mingming Cao617ba132006-10-11 01:20:53 -0700201 if (!cmp && ext4_xattr_check_entry(entry, size))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700202 return -EIO;
203 return cmp ? -ENODATA : 0;
204}
205
206static int
Mingming Cao617ba132006-10-11 01:20:53 -0700207ext4_xattr_block_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700208 void *buffer, size_t buffer_size)
209{
210 struct buffer_head *bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700211 struct ext4_xattr_entry *entry;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700212 size_t size;
213 int error;
214
215 ea_idebug(inode, "name=%d.%s, buffer=%p, buffer_size=%ld",
216 name_index, name, buffer, (long)buffer_size);
217
218 error = -ENODATA;
Mingming Cao617ba132006-10-11 01:20:53 -0700219 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700220 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700221 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
222 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700223 if (!bh)
224 goto cleanup;
225 ea_bdebug(bh, "b_count=%d, refcount=%d",
226 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700227 if (ext4_xattr_check_block(bh)) {
228bad_block: ext4_error(inode->i_sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700229 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700230 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700231 error = -EIO;
232 goto cleanup;
233 }
Mingming Cao617ba132006-10-11 01:20:53 -0700234 ext4_xattr_cache_insert(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700235 entry = BFIRST(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700236 error = ext4_xattr_find_entry(&entry, name_index, name, bh->b_size, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700237 if (error == -EIO)
238 goto bad_block;
239 if (error)
240 goto cleanup;
241 size = le32_to_cpu(entry->e_value_size);
242 if (buffer) {
243 error = -ERANGE;
244 if (size > buffer_size)
245 goto cleanup;
246 memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
247 size);
248 }
249 error = size;
250
251cleanup:
252 brelse(bh);
253 return error;
254}
255
256static int
Mingming Cao617ba132006-10-11 01:20:53 -0700257ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700258 void *buffer, size_t buffer_size)
259{
Mingming Cao617ba132006-10-11 01:20:53 -0700260 struct ext4_xattr_ibody_header *header;
261 struct ext4_xattr_entry *entry;
262 struct ext4_inode *raw_inode;
263 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700264 size_t size;
265 void *end;
266 int error;
267
Mingming Cao617ba132006-10-11 01:20:53 -0700268 if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700269 return -ENODATA;
Mingming Cao617ba132006-10-11 01:20:53 -0700270 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700271 if (error)
272 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700273 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700274 header = IHDR(inode, raw_inode);
275 entry = IFIRST(header);
Mingming Cao617ba132006-10-11 01:20:53 -0700276 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
277 error = ext4_xattr_check_names(entry, end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700278 if (error)
279 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700280 error = ext4_xattr_find_entry(&entry, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700281 end - (void *)entry, 0);
282 if (error)
283 goto cleanup;
284 size = le32_to_cpu(entry->e_value_size);
285 if (buffer) {
286 error = -ERANGE;
287 if (size > buffer_size)
288 goto cleanup;
289 memcpy(buffer, (void *)IFIRST(header) +
290 le16_to_cpu(entry->e_value_offs), size);
291 }
292 error = size;
293
294cleanup:
295 brelse(iloc.bh);
296 return error;
297}
298
299/*
Mingming Cao617ba132006-10-11 01:20:53 -0700300 * ext4_xattr_get()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700301 *
302 * Copy an extended attribute into the buffer
303 * provided, or compute the buffer size required.
304 * Buffer is NULL to compute the size of the buffer required.
305 *
306 * Returns a negative error number on failure, or the number of bytes
307 * used / required on success.
308 */
309int
Mingming Cao617ba132006-10-11 01:20:53 -0700310ext4_xattr_get(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700311 void *buffer, size_t buffer_size)
312{
313 int error;
314
Mingming Cao617ba132006-10-11 01:20:53 -0700315 down_read(&EXT4_I(inode)->xattr_sem);
316 error = ext4_xattr_ibody_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700317 buffer_size);
318 if (error == -ENODATA)
Mingming Cao617ba132006-10-11 01:20:53 -0700319 error = ext4_xattr_block_get(inode, name_index, name, buffer,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700320 buffer_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700321 up_read(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700322 return error;
323}
324
325static int
Mingming Cao617ba132006-10-11 01:20:53 -0700326ext4_xattr_list_entries(struct inode *inode, struct ext4_xattr_entry *entry,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700327 char *buffer, size_t buffer_size)
328{
329 size_t rest = buffer_size;
330
Mingming Cao617ba132006-10-11 01:20:53 -0700331 for (; !IS_LAST_ENTRY(entry); entry = EXT4_XATTR_NEXT(entry)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700332 struct xattr_handler *handler =
Mingming Cao617ba132006-10-11 01:20:53 -0700333 ext4_xattr_handler(entry->e_name_index);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700334
335 if (handler) {
336 size_t size = handler->list(inode, buffer, rest,
337 entry->e_name,
338 entry->e_name_len);
339 if (buffer) {
340 if (size > rest)
341 return -ERANGE;
342 buffer += size;
343 }
344 rest -= size;
345 }
346 }
347 return buffer_size - rest;
348}
349
350static int
Mingming Cao617ba132006-10-11 01:20:53 -0700351ext4_xattr_block_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700352{
353 struct buffer_head *bh = NULL;
354 int error;
355
356 ea_idebug(inode, "buffer=%p, buffer_size=%ld",
357 buffer, (long)buffer_size);
358
359 error = 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700360 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700361 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700362 ea_idebug(inode, "reading block %u", EXT4_I(inode)->i_file_acl);
363 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700364 error = -EIO;
365 if (!bh)
366 goto cleanup;
367 ea_bdebug(bh, "b_count=%d, refcount=%d",
368 atomic_read(&(bh->b_count)), le32_to_cpu(BHDR(bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700369 if (ext4_xattr_check_block(bh)) {
370 ext4_error(inode->i_sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700371 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700372 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700373 error = -EIO;
374 goto cleanup;
375 }
Mingming Cao617ba132006-10-11 01:20:53 -0700376 ext4_xattr_cache_insert(bh);
377 error = ext4_xattr_list_entries(inode, BFIRST(bh), buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700378
379cleanup:
380 brelse(bh);
381
382 return error;
383}
384
385static int
Mingming Cao617ba132006-10-11 01:20:53 -0700386ext4_xattr_ibody_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700387{
Mingming Cao617ba132006-10-11 01:20:53 -0700388 struct ext4_xattr_ibody_header *header;
389 struct ext4_inode *raw_inode;
390 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700391 void *end;
392 int error;
393
Mingming Cao617ba132006-10-11 01:20:53 -0700394 if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700395 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700396 error = ext4_get_inode_loc(inode, &iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700397 if (error)
398 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700399 raw_inode = ext4_raw_inode(&iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700400 header = IHDR(inode, raw_inode);
Mingming Cao617ba132006-10-11 01:20:53 -0700401 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
402 error = ext4_xattr_check_names(IFIRST(header), end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700403 if (error)
404 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700405 error = ext4_xattr_list_entries(inode, IFIRST(header),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700406 buffer, buffer_size);
407
408cleanup:
409 brelse(iloc.bh);
410 return error;
411}
412
413/*
Mingming Cao617ba132006-10-11 01:20:53 -0700414 * ext4_xattr_list()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700415 *
416 * Copy a list of attribute names into the buffer
417 * provided, or compute the buffer size required.
418 * Buffer is NULL to compute the size of the buffer required.
419 *
420 * Returns a negative error number on failure, or the number of bytes
421 * used / required on success.
422 */
423int
Mingming Cao617ba132006-10-11 01:20:53 -0700424ext4_xattr_list(struct inode *inode, char *buffer, size_t buffer_size)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700425{
426 int i_error, b_error;
427
Mingming Cao617ba132006-10-11 01:20:53 -0700428 down_read(&EXT4_I(inode)->xattr_sem);
429 i_error = ext4_xattr_ibody_list(inode, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700430 if (i_error < 0) {
431 b_error = 0;
432 } else {
433 if (buffer) {
434 buffer += i_error;
435 buffer_size -= i_error;
436 }
Mingming Cao617ba132006-10-11 01:20:53 -0700437 b_error = ext4_xattr_block_list(inode, buffer, buffer_size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700438 if (b_error < 0)
439 i_error = 0;
440 }
Mingming Cao617ba132006-10-11 01:20:53 -0700441 up_read(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700442 return i_error + b_error;
443}
444
445/*
Mingming Cao617ba132006-10-11 01:20:53 -0700446 * If the EXT4_FEATURE_COMPAT_EXT_ATTR feature of this file system is
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700447 * not set, set it.
448 */
Mingming Cao617ba132006-10-11 01:20:53 -0700449static void ext4_xattr_update_super_block(handle_t *handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700450 struct super_block *sb)
451{
Mingming Cao617ba132006-10-11 01:20:53 -0700452 if (EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700453 return;
454
Mingming Cao617ba132006-10-11 01:20:53 -0700455 if (ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh) == 0) {
Andreas Gruenbachered2908f2006-12-06 20:36:16 -0800456 EXT4_SET_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_EXT_ATTR);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700457 sb->s_dirt = 1;
Mingming Cao617ba132006-10-11 01:20:53 -0700458 ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700459 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700460}
461
462/*
463 * Release the xattr block BH: If the reference count is > 1, decrement
464 * it; otherwise free the block.
465 */
466static void
Mingming Cao617ba132006-10-11 01:20:53 -0700467ext4_xattr_release_block(handle_t *handle, struct inode *inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700468 struct buffer_head *bh)
469{
470 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800471 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700472
Mingming Cao617ba132006-10-11 01:20:53 -0700473 ce = mb_cache_entry_get(ext4_xattr_cache, bh->b_bdev, bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800474 error = ext4_journal_get_write_access(handle, bh);
475 if (error)
476 goto out;
477
478 lock_buffer(bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700479 if (BHDR(bh)->h_refcount == cpu_to_le32(1)) {
480 ea_bdebug(bh, "refcount now=0; freeing");
481 if (ce)
482 mb_cache_entry_free(ce);
Alex Tomasc9de5602008-01-29 00:19:52 -0500483 ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700484 get_bh(bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700485 ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700486 } else {
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800487 BHDR(bh)->h_refcount = cpu_to_le32(
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700488 le32_to_cpu(BHDR(bh)->h_refcount) - 1);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800489 error = ext4_journal_dirty_metadata(handle, bh);
490 if (IS_SYNC(inode))
491 handle->h_sync = 1;
492 DQUOT_FREE_BLOCK(inode, 1);
493 ea_bdebug(bh, "refcount now=%d; releasing",
494 le32_to_cpu(BHDR(bh)->h_refcount));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700495 if (ce)
496 mb_cache_entry_release(ce);
497 }
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800498 unlock_buffer(bh);
499out:
500 ext4_std_error(inode->i_sb, error);
501 return;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700502}
503
Kalpak Shah6dd4ee72007-07-18 09:19:57 -0400504/*
505 * Find the available free space for EAs. This also returns the total number of
506 * bytes used by EA entries.
507 */
508static size_t ext4_xattr_free_space(struct ext4_xattr_entry *last,
509 size_t *min_offs, void *base, int *total)
510{
511 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
512 *total += EXT4_XATTR_LEN(last->e_name_len);
513 if (!last->e_value_block && last->e_value_size) {
514 size_t offs = le16_to_cpu(last->e_value_offs);
515 if (offs < *min_offs)
516 *min_offs = offs;
517 }
518 }
519 return (*min_offs - ((void *)last - base) - sizeof(__u32));
520}
521
Mingming Cao617ba132006-10-11 01:20:53 -0700522struct ext4_xattr_info {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700523 int name_index;
524 const char *name;
525 const void *value;
526 size_t value_len;
527};
528
Mingming Cao617ba132006-10-11 01:20:53 -0700529struct ext4_xattr_search {
530 struct ext4_xattr_entry *first;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700531 void *base;
532 void *end;
Mingming Cao617ba132006-10-11 01:20:53 -0700533 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700534 int not_found;
535};
536
537static int
Mingming Cao617ba132006-10-11 01:20:53 -0700538ext4_xattr_set_entry(struct ext4_xattr_info *i, struct ext4_xattr_search *s)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700539{
Mingming Cao617ba132006-10-11 01:20:53 -0700540 struct ext4_xattr_entry *last;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700541 size_t free, min_offs = s->end - s->base, name_len = strlen(i->name);
542
543 /* Compute min_offs and last. */
544 last = s->first;
Mingming Cao617ba132006-10-11 01:20:53 -0700545 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700546 if (!last->e_value_block && last->e_value_size) {
547 size_t offs = le16_to_cpu(last->e_value_offs);
548 if (offs < min_offs)
549 min_offs = offs;
550 }
551 }
552 free = min_offs - ((void *)last - s->base) - sizeof(__u32);
553 if (!s->not_found) {
554 if (!s->here->e_value_block && s->here->e_value_size) {
555 size_t size = le32_to_cpu(s->here->e_value_size);
Mingming Cao617ba132006-10-11 01:20:53 -0700556 free += EXT4_XATTR_SIZE(size);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700557 }
Mingming Cao617ba132006-10-11 01:20:53 -0700558 free += EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700559 }
560 if (i->value) {
Mingming Cao617ba132006-10-11 01:20:53 -0700561 if (free < EXT4_XATTR_SIZE(i->value_len) ||
562 free < EXT4_XATTR_LEN(name_len) +
563 EXT4_XATTR_SIZE(i->value_len))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700564 return -ENOSPC;
565 }
566
567 if (i->value && s->not_found) {
568 /* Insert the new name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700569 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700570 size_t rest = (void *)last - (void *)s->here + sizeof(__u32);
571 memmove((void *)s->here + size, s->here, rest);
572 memset(s->here, 0, size);
573 s->here->e_name_index = i->name_index;
574 s->here->e_name_len = name_len;
575 memcpy(s->here->e_name, i->name, name_len);
576 } else {
577 if (!s->here->e_value_block && s->here->e_value_size) {
578 void *first_val = s->base + min_offs;
579 size_t offs = le16_to_cpu(s->here->e_value_offs);
580 void *val = s->base + offs;
Mingming Cao617ba132006-10-11 01:20:53 -0700581 size_t size = EXT4_XATTR_SIZE(
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700582 le32_to_cpu(s->here->e_value_size));
583
Mingming Cao617ba132006-10-11 01:20:53 -0700584 if (i->value && size == EXT4_XATTR_SIZE(i->value_len)) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700585 /* The old and the new value have the same
586 size. Just replace. */
587 s->here->e_value_size =
588 cpu_to_le32(i->value_len);
Mingming Cao617ba132006-10-11 01:20:53 -0700589 memset(val + size - EXT4_XATTR_PAD, 0,
590 EXT4_XATTR_PAD); /* Clear pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700591 memcpy(val, i->value, i->value_len);
592 return 0;
593 }
594
595 /* Remove the old value. */
596 memmove(first_val + size, first_val, val - first_val);
597 memset(first_val, 0, size);
598 s->here->e_value_size = 0;
599 s->here->e_value_offs = 0;
600 min_offs += size;
601
602 /* Adjust all value offsets. */
603 last = s->first;
604 while (!IS_LAST_ENTRY(last)) {
605 size_t o = le16_to_cpu(last->e_value_offs);
606 if (!last->e_value_block &&
607 last->e_value_size && o < offs)
608 last->e_value_offs =
609 cpu_to_le16(o + size);
Mingming Cao617ba132006-10-11 01:20:53 -0700610 last = EXT4_XATTR_NEXT(last);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700611 }
612 }
613 if (!i->value) {
614 /* Remove the old name. */
Mingming Cao617ba132006-10-11 01:20:53 -0700615 size_t size = EXT4_XATTR_LEN(name_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700616 last = ENTRY((void *)last - size);
617 memmove(s->here, (void *)s->here + size,
618 (void *)last - (void *)s->here + sizeof(__u32));
619 memset(last, 0, size);
620 }
621 }
622
623 if (i->value) {
624 /* Insert the new value. */
625 s->here->e_value_size = cpu_to_le32(i->value_len);
626 if (i->value_len) {
Mingming Cao617ba132006-10-11 01:20:53 -0700627 size_t size = EXT4_XATTR_SIZE(i->value_len);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700628 void *val = s->base + min_offs - size;
629 s->here->e_value_offs = cpu_to_le16(min_offs - size);
Mingming Cao617ba132006-10-11 01:20:53 -0700630 memset(val + size - EXT4_XATTR_PAD, 0,
631 EXT4_XATTR_PAD); /* Clear the pad bytes. */
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700632 memcpy(val, i->value, i->value_len);
633 }
634 }
635 return 0;
636}
637
Mingming Cao617ba132006-10-11 01:20:53 -0700638struct ext4_xattr_block_find {
639 struct ext4_xattr_search s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700640 struct buffer_head *bh;
641};
642
643static int
Mingming Cao617ba132006-10-11 01:20:53 -0700644ext4_xattr_block_find(struct inode *inode, struct ext4_xattr_info *i,
645 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700646{
647 struct super_block *sb = inode->i_sb;
648 int error;
649
650 ea_idebug(inode, "name=%d.%s, value=%p, value_len=%ld",
651 i->name_index, i->name, i->value, (long)i->value_len);
652
Mingming Cao617ba132006-10-11 01:20:53 -0700653 if (EXT4_I(inode)->i_file_acl) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700654 /* The inode already has an extended attribute block. */
Mingming Cao617ba132006-10-11 01:20:53 -0700655 bs->bh = sb_bread(sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700656 error = -EIO;
657 if (!bs->bh)
658 goto cleanup;
659 ea_bdebug(bs->bh, "b_count=%d, refcount=%d",
660 atomic_read(&(bs->bh->b_count)),
661 le32_to_cpu(BHDR(bs->bh)->h_refcount));
Mingming Cao617ba132006-10-11 01:20:53 -0700662 if (ext4_xattr_check_block(bs->bh)) {
663 ext4_error(sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700664 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700665 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700666 error = -EIO;
667 goto cleanup;
668 }
669 /* Find the named attribute. */
670 bs->s.base = BHDR(bs->bh);
671 bs->s.first = BFIRST(bs->bh);
672 bs->s.end = bs->bh->b_data + bs->bh->b_size;
673 bs->s.here = bs->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700674 error = ext4_xattr_find_entry(&bs->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700675 i->name, bs->bh->b_size, 1);
676 if (error && error != -ENODATA)
677 goto cleanup;
678 bs->s.not_found = error;
679 }
680 error = 0;
681
682cleanup:
683 return error;
684}
685
686static int
Mingming Cao617ba132006-10-11 01:20:53 -0700687ext4_xattr_block_set(handle_t *handle, struct inode *inode,
688 struct ext4_xattr_info *i,
689 struct ext4_xattr_block_find *bs)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700690{
691 struct super_block *sb = inode->i_sb;
692 struct buffer_head *new_bh = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -0700693 struct ext4_xattr_search *s = &bs->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700694 struct mb_cache_entry *ce = NULL;
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800695 int error = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700696
Mingming Cao617ba132006-10-11 01:20:53 -0700697#define header(x) ((struct ext4_xattr_header *)(x))
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700698
699 if (i->value && i->value_len > sb->s_blocksize)
700 return -ENOSPC;
701 if (s->base) {
Mingming Cao617ba132006-10-11 01:20:53 -0700702 ce = mb_cache_entry_get(ext4_xattr_cache, bs->bh->b_bdev,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700703 bs->bh->b_blocknr);
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800704 error = ext4_journal_get_write_access(handle, bs->bh);
705 if (error)
706 goto cleanup;
707 lock_buffer(bs->bh);
708
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700709 if (header(s->base)->h_refcount == cpu_to_le32(1)) {
710 if (ce) {
711 mb_cache_entry_free(ce);
712 ce = NULL;
713 }
714 ea_bdebug(bs->bh, "modifying in-place");
Mingming Cao617ba132006-10-11 01:20:53 -0700715 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700716 if (!error) {
717 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700718 ext4_xattr_rehash(header(s->base),
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700719 s->here);
Mingming Cao617ba132006-10-11 01:20:53 -0700720 ext4_xattr_cache_insert(bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700721 }
722 unlock_buffer(bs->bh);
723 if (error == -EIO)
724 goto bad_block;
725 if (!error)
Mingming Cao617ba132006-10-11 01:20:53 -0700726 error = ext4_journal_dirty_metadata(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700727 bs->bh);
728 if (error)
729 goto cleanup;
730 goto inserted;
731 } else {
732 int offset = (char *)s->here - bs->bh->b_data;
733
Mingming Cao8a2bfdc2007-02-28 20:13:35 -0800734 unlock_buffer(bs->bh);
735 jbd2_journal_release_buffer(handle, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700736 if (ce) {
737 mb_cache_entry_release(ce);
738 ce = NULL;
739 }
740 ea_bdebug(bs->bh, "cloning");
741 s->base = kmalloc(bs->bh->b_size, GFP_KERNEL);
742 error = -ENOMEM;
743 if (s->base == NULL)
744 goto cleanup;
745 memcpy(s->base, BHDR(bs->bh), bs->bh->b_size);
746 s->first = ENTRY(header(s->base)+1);
747 header(s->base)->h_refcount = cpu_to_le32(1);
748 s->here = ENTRY(s->base + offset);
749 s->end = s->base + bs->bh->b_size;
750 }
751 } else {
752 /* Allocate a buffer where we construct the new block. */
Mingming Caod802ffa2007-10-16 18:38:25 -0400753 s->base = kzalloc(sb->s_blocksize, GFP_KERNEL);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700754 /* assert(header == s->base) */
755 error = -ENOMEM;
756 if (s->base == NULL)
757 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700758 header(s->base)->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700759 header(s->base)->h_blocks = cpu_to_le32(1);
760 header(s->base)->h_refcount = cpu_to_le32(1);
761 s->first = ENTRY(header(s->base)+1);
762 s->here = ENTRY(header(s->base)+1);
763 s->end = s->base + sb->s_blocksize;
764 }
765
Mingming Cao617ba132006-10-11 01:20:53 -0700766 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700767 if (error == -EIO)
768 goto bad_block;
769 if (error)
770 goto cleanup;
771 if (!IS_LAST_ENTRY(s->first))
Mingming Cao617ba132006-10-11 01:20:53 -0700772 ext4_xattr_rehash(header(s->base), s->here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700773
774inserted:
775 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700776 new_bh = ext4_xattr_cache_find(inode, header(s->base), &ce);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700777 if (new_bh) {
778 /* We found an identical block in the cache. */
779 if (new_bh == bs->bh)
780 ea_bdebug(new_bh, "keeping");
781 else {
782 /* The old block is released after updating
783 the inode. */
784 error = -EDQUOT;
785 if (DQUOT_ALLOC_BLOCK(inode, 1))
786 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -0700787 error = ext4_journal_get_write_access(handle,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700788 new_bh);
789 if (error)
790 goto cleanup_dquot;
791 lock_buffer(new_bh);
792 BHDR(new_bh)->h_refcount = cpu_to_le32(1 +
793 le32_to_cpu(BHDR(new_bh)->h_refcount));
794 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 */
Mingming Cao617ba132006-10-11 01:20:53 -0700811 ext4_fsblk_t goal = le32_to_cpu(
812 EXT4_SB(sb)->s_es->s_first_data_block) +
813 (ext4_fsblk_t)EXT4_I(inode)->i_block_group *
814 EXT4_BLOCKS_PER_GROUP(sb);
815 ext4_fsblk_t block = ext4_new_block(handle, inode,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700816 goal, &error);
817 if (error)
818 goto cleanup;
819 ea_idebug(inode, "creating block %d", block);
820
821 new_bh = sb_getblk(sb, block);
822 if (!new_bh) {
823getblk_failed:
Alex Tomasc9de5602008-01-29 00:19:52 -0500824 ext4_free_blocks(handle, inode, block, 1, 1);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700825 error = -EIO;
826 goto cleanup;
827 }
828 lock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700829 error = ext4_journal_get_create_access(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700830 if (error) {
831 unlock_buffer(new_bh);
832 goto getblk_failed;
833 }
834 memcpy(new_bh->b_data, s->base, new_bh->b_size);
835 set_buffer_uptodate(new_bh);
836 unlock_buffer(new_bh);
Mingming Cao617ba132006-10-11 01:20:53 -0700837 ext4_xattr_cache_insert(new_bh);
838 error = ext4_journal_dirty_metadata(handle, new_bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700839 if (error)
840 goto cleanup;
841 }
842 }
843
844 /* Update the inode. */
Mingming Cao617ba132006-10-11 01:20:53 -0700845 EXT4_I(inode)->i_file_acl = new_bh ? new_bh->b_blocknr : 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700846
847 /* Drop the previous xattr block. */
848 if (bs->bh && bs->bh != new_bh)
Mingming Cao617ba132006-10-11 01:20:53 -0700849 ext4_xattr_release_block(handle, inode, bs->bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700850 error = 0;
851
852cleanup:
853 if (ce)
854 mb_cache_entry_release(ce);
855 brelse(new_bh);
856 if (!(bs->bh && s->base == bs->bh->b_data))
857 kfree(s->base);
858
859 return error;
860
861cleanup_dquot:
862 DQUOT_FREE_BLOCK(inode, 1);
863 goto cleanup;
864
865bad_block:
Mingming Cao617ba132006-10-11 01:20:53 -0700866 ext4_error(inode->i_sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -0700867 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -0700868 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700869 goto cleanup;
870
871#undef header
872}
873
Mingming Cao617ba132006-10-11 01:20:53 -0700874struct ext4_xattr_ibody_find {
875 struct ext4_xattr_search s;
876 struct ext4_iloc iloc;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700877};
878
879static int
Mingming Cao617ba132006-10-11 01:20:53 -0700880ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
881 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700882{
Mingming Cao617ba132006-10-11 01:20:53 -0700883 struct ext4_xattr_ibody_header *header;
884 struct ext4_inode *raw_inode;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700885 int error;
886
Mingming Cao617ba132006-10-11 01:20:53 -0700887 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700888 return 0;
Mingming Cao617ba132006-10-11 01:20:53 -0700889 raw_inode = ext4_raw_inode(&is->iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700890 header = IHDR(inode, raw_inode);
891 is->s.base = is->s.first = IFIRST(header);
892 is->s.here = is->s.first;
Mingming Cao617ba132006-10-11 01:20:53 -0700893 is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
894 if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
895 error = ext4_xattr_check_names(IFIRST(header), is->s.end);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700896 if (error)
897 return error;
898 /* Find the named attribute. */
Mingming Cao617ba132006-10-11 01:20:53 -0700899 error = ext4_xattr_find_entry(&is->s.here, i->name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700900 i->name, is->s.end -
901 (void *)is->s.base, 0);
902 if (error && error != -ENODATA)
903 return error;
904 is->s.not_found = error;
905 }
906 return 0;
907}
908
909static int
Mingming Cao617ba132006-10-11 01:20:53 -0700910ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
911 struct ext4_xattr_info *i,
912 struct ext4_xattr_ibody_find *is)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700913{
Mingming Cao617ba132006-10-11 01:20:53 -0700914 struct ext4_xattr_ibody_header *header;
915 struct ext4_xattr_search *s = &is->s;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700916 int error;
917
Mingming Cao617ba132006-10-11 01:20:53 -0700918 if (EXT4_I(inode)->i_extra_isize == 0)
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700919 return -ENOSPC;
Mingming Cao617ba132006-10-11 01:20:53 -0700920 error = ext4_xattr_set_entry(i, s);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700921 if (error)
922 return error;
Mingming Cao617ba132006-10-11 01:20:53 -0700923 header = IHDR(inode, ext4_raw_inode(&is->iloc));
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700924 if (!IS_LAST_ENTRY(s->first)) {
Mingming Cao617ba132006-10-11 01:20:53 -0700925 header->h_magic = cpu_to_le32(EXT4_XATTR_MAGIC);
926 EXT4_I(inode)->i_state |= EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700927 } else {
928 header->h_magic = cpu_to_le32(0);
Mingming Cao617ba132006-10-11 01:20:53 -0700929 EXT4_I(inode)->i_state &= ~EXT4_STATE_XATTR;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700930 }
931 return 0;
932}
933
934/*
Mingming Cao617ba132006-10-11 01:20:53 -0700935 * ext4_xattr_set_handle()
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700936 *
937 * Create, replace or remove an extended attribute for this inode. Buffer
938 * is NULL to remove an existing extended attribute, and non-NULL to
939 * either replace an existing extended attribute, or create a new extended
940 * attribute. The flags XATTR_REPLACE and XATTR_CREATE
941 * specify that an extended attribute must exist and must not exist
942 * previous to the call, respectively.
943 *
944 * Returns 0, or a negative error number on failure.
945 */
946int
Mingming Cao617ba132006-10-11 01:20:53 -0700947ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700948 const char *name, const void *value, size_t value_len,
949 int flags)
950{
Mingming Cao617ba132006-10-11 01:20:53 -0700951 struct ext4_xattr_info i = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700952 .name_index = name_index,
953 .name = name,
954 .value = value,
955 .value_len = value_len,
956
957 };
Mingming Cao617ba132006-10-11 01:20:53 -0700958 struct ext4_xattr_ibody_find is = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700959 .s = { .not_found = -ENODATA, },
960 };
Mingming Cao617ba132006-10-11 01:20:53 -0700961 struct ext4_xattr_block_find bs = {
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700962 .s = { .not_found = -ENODATA, },
963 };
964 int error;
965
966 if (!name)
967 return -EINVAL;
968 if (strlen(name) > 255)
969 return -ERANGE;
Mingming Cao617ba132006-10-11 01:20:53 -0700970 down_write(&EXT4_I(inode)->xattr_sem);
971 error = ext4_get_inode_loc(inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700972 if (error)
973 goto cleanup;
974
Mingming Cao617ba132006-10-11 01:20:53 -0700975 if (EXT4_I(inode)->i_state & EXT4_STATE_NEW) {
976 struct ext4_inode *raw_inode = ext4_raw_inode(&is.iloc);
977 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
978 EXT4_I(inode)->i_state &= ~EXT4_STATE_NEW;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700979 }
980
Mingming Cao617ba132006-10-11 01:20:53 -0700981 error = ext4_xattr_ibody_find(inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700982 if (error)
983 goto cleanup;
984 if (is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -0700985 error = ext4_xattr_block_find(inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700986 if (error)
987 goto cleanup;
988 if (is.s.not_found && bs.s.not_found) {
989 error = -ENODATA;
990 if (flags & XATTR_REPLACE)
991 goto cleanup;
992 error = 0;
993 if (!value)
994 goto cleanup;
995 } else {
996 error = -EEXIST;
997 if (flags & XATTR_CREATE)
998 goto cleanup;
999 }
Mingming Cao617ba132006-10-11 01:20:53 -07001000 error = ext4_journal_get_write_access(handle, is.iloc.bh);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001001 if (error)
1002 goto cleanup;
1003 if (!value) {
1004 if (!is.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001005 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001006 else if (!bs.s.not_found)
Mingming Cao617ba132006-10-11 01:20:53 -07001007 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001008 } else {
Mingming Cao617ba132006-10-11 01:20:53 -07001009 error = ext4_xattr_ibody_set(handle, inode, &i, &is);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001010 if (!error && !bs.s.not_found) {
1011 i.value = NULL;
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 } else if (error == -ENOSPC) {
Mingming Cao617ba132006-10-11 01:20:53 -07001014 error = ext4_xattr_block_set(handle, inode, &i, &bs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001015 if (error)
1016 goto cleanup;
1017 if (!is.s.not_found) {
1018 i.value = NULL;
Mingming Cao617ba132006-10-11 01:20:53 -07001019 error = ext4_xattr_ibody_set(handle, inode, &i,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001020 &is);
1021 }
1022 }
1023 }
1024 if (!error) {
Mingming Cao617ba132006-10-11 01:20:53 -07001025 ext4_xattr_update_super_block(handle, inode->i_sb);
Kalpak Shahef7f3832007-07-18 09:15:20 -04001026 inode->i_ctime = ext4_current_time(inode);
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001027 if (!value)
1028 EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
Mingming Cao617ba132006-10-11 01:20:53 -07001029 error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001030 /*
Mingming Cao617ba132006-10-11 01:20:53 -07001031 * The bh is consumed by ext4_mark_iloc_dirty, even with
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001032 * error != 0.
1033 */
1034 is.iloc.bh = NULL;
1035 if (IS_SYNC(inode))
1036 handle->h_sync = 1;
1037 }
1038
1039cleanup:
1040 brelse(is.iloc.bh);
1041 brelse(bs.bh);
Mingming Cao617ba132006-10-11 01:20:53 -07001042 up_write(&EXT4_I(inode)->xattr_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001043 return error;
1044}
1045
1046/*
Mingming Cao617ba132006-10-11 01:20:53 -07001047 * ext4_xattr_set()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001048 *
Mingming Cao617ba132006-10-11 01:20:53 -07001049 * Like ext4_xattr_set_handle, but start from an inode. This extended
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001050 * attribute modification is a filesystem transaction by itself.
1051 *
1052 * Returns 0, or a negative error number on failure.
1053 */
1054int
Mingming Cao617ba132006-10-11 01:20:53 -07001055ext4_xattr_set(struct inode *inode, int name_index, const char *name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001056 const void *value, size_t value_len, int flags)
1057{
1058 handle_t *handle;
1059 int error, retries = 0;
1060
1061retry:
Mingming Cao617ba132006-10-11 01:20:53 -07001062 handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001063 if (IS_ERR(handle)) {
1064 error = PTR_ERR(handle);
1065 } else {
1066 int error2;
1067
Mingming Cao617ba132006-10-11 01:20:53 -07001068 error = ext4_xattr_set_handle(handle, inode, name_index, name,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001069 value, value_len, flags);
Mingming Cao617ba132006-10-11 01:20:53 -07001070 error2 = ext4_journal_stop(handle);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001071 if (error == -ENOSPC &&
Mingming Cao617ba132006-10-11 01:20:53 -07001072 ext4_should_retry_alloc(inode->i_sb, &retries))
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001073 goto retry;
1074 if (error == 0)
1075 error = error2;
1076 }
1077
1078 return error;
1079}
1080
1081/*
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001082 * Shift the EA entries in the inode to create space for the increased
1083 * i_extra_isize.
1084 */
1085static void ext4_xattr_shift_entries(struct ext4_xattr_entry *entry,
1086 int value_offs_shift, void *to,
1087 void *from, size_t n, int blocksize)
1088{
1089 struct ext4_xattr_entry *last = entry;
1090 int new_offs;
1091
1092 /* Adjust the value offsets of the entries */
1093 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1094 if (!last->e_value_block && last->e_value_size) {
1095 new_offs = le16_to_cpu(last->e_value_offs) +
1096 value_offs_shift;
1097 BUG_ON(new_offs + le32_to_cpu(last->e_value_size)
1098 > blocksize);
1099 last->e_value_offs = cpu_to_le16(new_offs);
1100 }
1101 }
1102 /* Shift the entries by n bytes */
1103 memmove(to, from, n);
1104}
1105
1106/*
1107 * Expand an inode by new_extra_isize bytes when EAs are present.
1108 * Returns 0 on success or negative error number on failure.
1109 */
1110int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
1111 struct ext4_inode *raw_inode, handle_t *handle)
1112{
1113 struct ext4_xattr_ibody_header *header;
1114 struct ext4_xattr_entry *entry, *last, *first;
1115 struct buffer_head *bh = NULL;
1116 struct ext4_xattr_ibody_find *is = NULL;
1117 struct ext4_xattr_block_find *bs = NULL;
1118 char *buffer = NULL, *b_entry_name = NULL;
1119 size_t min_offs, free;
1120 int total_ino, total_blk;
1121 void *base, *start, *end;
1122 int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001123 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 -04001124
1125 down_write(&EXT4_I(inode)->xattr_sem);
1126retry:
1127 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
1128 up_write(&EXT4_I(inode)->xattr_sem);
1129 return 0;
1130 }
1131
1132 header = IHDR(inode, raw_inode);
1133 entry = IFIRST(header);
1134
1135 /*
1136 * Check if enough free space is available in the inode to shift the
1137 * entries ahead by new_extra_isize.
1138 */
1139
1140 base = start = entry;
1141 end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size;
1142 min_offs = end - base;
1143 last = entry;
1144 total_ino = sizeof(struct ext4_xattr_ibody_header);
1145
1146 free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
1147 if (free >= new_extra_isize) {
1148 entry = IFIRST(header);
1149 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
1150 - new_extra_isize, (void *)raw_inode +
1151 EXT4_GOOD_OLD_INODE_SIZE + new_extra_isize,
1152 (void *)header, total_ino,
1153 inode->i_sb->s_blocksize);
1154 EXT4_I(inode)->i_extra_isize = new_extra_isize;
1155 error = 0;
1156 goto cleanup;
1157 }
1158
1159 /*
1160 * Enough free space isn't available in the inode, check if
1161 * EA block can hold new_extra_isize bytes.
1162 */
1163 if (EXT4_I(inode)->i_file_acl) {
1164 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
1165 error = -EIO;
1166 if (!bh)
1167 goto cleanup;
1168 if (ext4_xattr_check_block(bh)) {
1169 ext4_error(inode->i_sb, __FUNCTION__,
1170 "inode %lu: bad block %llu", inode->i_ino,
1171 EXT4_I(inode)->i_file_acl);
1172 error = -EIO;
1173 goto cleanup;
1174 }
1175 base = BHDR(bh);
1176 first = BFIRST(bh);
1177 end = bh->b_data + bh->b_size;
1178 min_offs = end - base;
1179 free = ext4_xattr_free_space(first, &min_offs, base,
1180 &total_blk);
1181 if (free < new_extra_isize) {
1182 if (!tried_min_extra_isize && s_min_extra_isize) {
1183 tried_min_extra_isize++;
1184 new_extra_isize = s_min_extra_isize;
1185 brelse(bh);
1186 goto retry;
1187 }
1188 error = -1;
1189 goto cleanup;
1190 }
1191 } else {
1192 free = inode->i_sb->s_blocksize;
1193 }
1194
1195 while (new_extra_isize > 0) {
1196 size_t offs, size, entry_size;
1197 struct ext4_xattr_entry *small_entry = NULL;
1198 struct ext4_xattr_info i = {
1199 .value = NULL,
1200 .value_len = 0,
1201 };
1202 unsigned int total_size; /* EA entry size + value size */
1203 unsigned int shift_bytes; /* No. of bytes to shift EAs by? */
1204 unsigned int min_total_size = ~0U;
1205
1206 is = kzalloc(sizeof(struct ext4_xattr_ibody_find), GFP_NOFS);
1207 bs = kzalloc(sizeof(struct ext4_xattr_block_find), GFP_NOFS);
1208 if (!is || !bs) {
1209 error = -ENOMEM;
1210 goto cleanup;
1211 }
1212
1213 is->s.not_found = -ENODATA;
1214 bs->s.not_found = -ENODATA;
1215 is->iloc.bh = NULL;
1216 bs->bh = NULL;
1217
1218 last = IFIRST(header);
1219 /* Find the entry best suited to be pushed into EA block */
1220 entry = NULL;
1221 for (; !IS_LAST_ENTRY(last); last = EXT4_XATTR_NEXT(last)) {
1222 total_size =
1223 EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
1224 EXT4_XATTR_LEN(last->e_name_len);
1225 if (total_size <= free && total_size < min_total_size) {
1226 if (total_size < new_extra_isize) {
1227 small_entry = last;
1228 } else {
1229 entry = last;
1230 min_total_size = total_size;
1231 }
1232 }
1233 }
1234
1235 if (entry == NULL) {
1236 if (small_entry) {
1237 entry = small_entry;
1238 } else {
1239 if (!tried_min_extra_isize &&
1240 s_min_extra_isize) {
1241 tried_min_extra_isize++;
1242 new_extra_isize = s_min_extra_isize;
1243 goto retry;
1244 }
1245 error = -1;
1246 goto cleanup;
1247 }
1248 }
1249 offs = le16_to_cpu(entry->e_value_offs);
1250 size = le32_to_cpu(entry->e_value_size);
1251 entry_size = EXT4_XATTR_LEN(entry->e_name_len);
1252 i.name_index = entry->e_name_index,
1253 buffer = kmalloc(EXT4_XATTR_SIZE(size), GFP_NOFS);
1254 b_entry_name = kmalloc(entry->e_name_len + 1, GFP_NOFS);
1255 if (!buffer || !b_entry_name) {
1256 error = -ENOMEM;
1257 goto cleanup;
1258 }
1259 /* Save the entry name and the entry value */
1260 memcpy(buffer, (void *)IFIRST(header) + offs,
1261 EXT4_XATTR_SIZE(size));
1262 memcpy(b_entry_name, entry->e_name, entry->e_name_len);
1263 b_entry_name[entry->e_name_len] = '\0';
1264 i.name = b_entry_name;
1265
1266 error = ext4_get_inode_loc(inode, &is->iloc);
1267 if (error)
1268 goto cleanup;
1269
1270 error = ext4_xattr_ibody_find(inode, &i, is);
1271 if (error)
1272 goto cleanup;
1273
1274 /* Remove the chosen entry from the inode */
1275 error = ext4_xattr_ibody_set(handle, inode, &i, is);
1276
1277 entry = IFIRST(header);
1278 if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
1279 shift_bytes = new_extra_isize;
1280 else
1281 shift_bytes = entry_size + size;
1282 /* Adjust the offsets and shift the remaining entries ahead */
1283 ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
1284 shift_bytes, (void *)raw_inode +
1285 EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
1286 (void *)header, total_ino - entry_size,
1287 inode->i_sb->s_blocksize);
1288
1289 extra_isize += shift_bytes;
1290 new_extra_isize -= shift_bytes;
1291 EXT4_I(inode)->i_extra_isize = extra_isize;
1292
1293 i.name = b_entry_name;
1294 i.value = buffer;
Aneesh Kumar K.Vac398492007-10-16 18:38:25 -04001295 i.value_len = size;
Kalpak Shah6dd4ee72007-07-18 09:19:57 -04001296 error = ext4_xattr_block_find(inode, &i, bs);
1297 if (error)
1298 goto cleanup;
1299
1300 /* Add entry which was removed from the inode into the block */
1301 error = ext4_xattr_block_set(handle, inode, &i, bs);
1302 if (error)
1303 goto cleanup;
1304 kfree(b_entry_name);
1305 kfree(buffer);
1306 brelse(is->iloc.bh);
1307 kfree(is);
1308 kfree(bs);
1309 }
1310 brelse(bh);
1311 up_write(&EXT4_I(inode)->xattr_sem);
1312 return 0;
1313
1314cleanup:
1315 kfree(b_entry_name);
1316 kfree(buffer);
1317 if (is)
1318 brelse(is->iloc.bh);
1319 kfree(is);
1320 kfree(bs);
1321 brelse(bh);
1322 up_write(&EXT4_I(inode)->xattr_sem);
1323 return error;
1324}
1325
1326
1327
1328/*
Mingming Cao617ba132006-10-11 01:20:53 -07001329 * ext4_xattr_delete_inode()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001330 *
1331 * Free extended attribute resources associated with this inode. This
1332 * is called immediately before an inode is freed. We have exclusive
1333 * access to the inode.
1334 */
1335void
Mingming Cao617ba132006-10-11 01:20:53 -07001336ext4_xattr_delete_inode(handle_t *handle, struct inode *inode)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001337{
1338 struct buffer_head *bh = NULL;
1339
Mingming Cao617ba132006-10-11 01:20:53 -07001340 if (!EXT4_I(inode)->i_file_acl)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001341 goto cleanup;
Mingming Cao617ba132006-10-11 01:20:53 -07001342 bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001343 if (!bh) {
Mingming Cao617ba132006-10-11 01:20:53 -07001344 ext4_error(inode->i_sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -07001345 "inode %lu: block %llu read error", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -07001346 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001347 goto cleanup;
1348 }
Mingming Cao617ba132006-10-11 01:20:53 -07001349 if (BHDR(bh)->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC) ||
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001350 BHDR(bh)->h_blocks != cpu_to_le32(1)) {
Mingming Cao617ba132006-10-11 01:20:53 -07001351 ext4_error(inode->i_sb, __FUNCTION__,
Mingming Cao2ae02102006-10-11 01:21:11 -07001352 "inode %lu: bad block %llu", inode->i_ino,
Mingming Cao617ba132006-10-11 01:20:53 -07001353 EXT4_I(inode)->i_file_acl);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001354 goto cleanup;
1355 }
Mingming Cao617ba132006-10-11 01:20:53 -07001356 ext4_xattr_release_block(handle, inode, bh);
1357 EXT4_I(inode)->i_file_acl = 0;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001358
1359cleanup:
1360 brelse(bh);
1361}
1362
1363/*
Mingming Cao617ba132006-10-11 01:20:53 -07001364 * ext4_xattr_put_super()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001365 *
1366 * This is called when a file system is unmounted.
1367 */
1368void
Mingming Cao617ba132006-10-11 01:20:53 -07001369ext4_xattr_put_super(struct super_block *sb)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001370{
1371 mb_cache_shrink(sb->s_bdev);
1372}
1373
1374/*
Mingming Cao617ba132006-10-11 01:20:53 -07001375 * ext4_xattr_cache_insert()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001376 *
1377 * Create a new entry in the extended attribute cache, and insert
1378 * it unless such an entry is already in the cache.
1379 *
1380 * Returns 0, or a negative error number on failure.
1381 */
1382static void
Mingming Cao617ba132006-10-11 01:20:53 -07001383ext4_xattr_cache_insert(struct buffer_head *bh)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001384{
1385 __u32 hash = le32_to_cpu(BHDR(bh)->h_hash);
1386 struct mb_cache_entry *ce;
1387 int error;
1388
Jan Kara335e92e2008-04-15 14:34:43 -07001389 ce = mb_cache_entry_alloc(ext4_xattr_cache, GFP_NOFS);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001390 if (!ce) {
1391 ea_bdebug(bh, "out of memory");
1392 return;
1393 }
1394 error = mb_cache_entry_insert(ce, bh->b_bdev, bh->b_blocknr, &hash);
1395 if (error) {
1396 mb_cache_entry_free(ce);
1397 if (error == -EBUSY) {
1398 ea_bdebug(bh, "already in cache");
1399 error = 0;
1400 }
1401 } else {
1402 ea_bdebug(bh, "inserting [%x]", (int)hash);
1403 mb_cache_entry_release(ce);
1404 }
1405}
1406
1407/*
Mingming Cao617ba132006-10-11 01:20:53 -07001408 * ext4_xattr_cmp()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001409 *
1410 * Compare two extended attribute blocks for equality.
1411 *
1412 * Returns 0 if the blocks are equal, 1 if they differ, and
1413 * a negative error number on errors.
1414 */
1415static int
Mingming Cao617ba132006-10-11 01:20:53 -07001416ext4_xattr_cmp(struct ext4_xattr_header *header1,
1417 struct ext4_xattr_header *header2)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001418{
Mingming Cao617ba132006-10-11 01:20:53 -07001419 struct ext4_xattr_entry *entry1, *entry2;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001420
1421 entry1 = ENTRY(header1+1);
1422 entry2 = ENTRY(header2+1);
1423 while (!IS_LAST_ENTRY(entry1)) {
1424 if (IS_LAST_ENTRY(entry2))
1425 return 1;
1426 if (entry1->e_hash != entry2->e_hash ||
1427 entry1->e_name_index != entry2->e_name_index ||
1428 entry1->e_name_len != entry2->e_name_len ||
1429 entry1->e_value_size != entry2->e_value_size ||
1430 memcmp(entry1->e_name, entry2->e_name, entry1->e_name_len))
1431 return 1;
1432 if (entry1->e_value_block != 0 || entry2->e_value_block != 0)
1433 return -EIO;
1434 if (memcmp((char *)header1 + le16_to_cpu(entry1->e_value_offs),
1435 (char *)header2 + le16_to_cpu(entry2->e_value_offs),
1436 le32_to_cpu(entry1->e_value_size)))
1437 return 1;
1438
Mingming Cao617ba132006-10-11 01:20:53 -07001439 entry1 = EXT4_XATTR_NEXT(entry1);
1440 entry2 = EXT4_XATTR_NEXT(entry2);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001441 }
1442 if (!IS_LAST_ENTRY(entry2))
1443 return 1;
1444 return 0;
1445}
1446
1447/*
Mingming Cao617ba132006-10-11 01:20:53 -07001448 * ext4_xattr_cache_find()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001449 *
1450 * Find an identical extended attribute block.
1451 *
1452 * Returns a pointer to the block found, or NULL if such a block was
1453 * not found or an error occurred.
1454 */
1455static struct buffer_head *
Mingming Cao617ba132006-10-11 01:20:53 -07001456ext4_xattr_cache_find(struct inode *inode, struct ext4_xattr_header *header,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001457 struct mb_cache_entry **pce)
1458{
1459 __u32 hash = le32_to_cpu(header->h_hash);
1460 struct mb_cache_entry *ce;
1461
1462 if (!header->h_hash)
1463 return NULL; /* never share */
1464 ea_idebug(inode, "looking for cached blocks [%x]", (int)hash);
1465again:
Mingming Cao617ba132006-10-11 01:20:53 -07001466 ce = mb_cache_entry_find_first(ext4_xattr_cache, 0,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001467 inode->i_sb->s_bdev, hash);
1468 while (ce) {
1469 struct buffer_head *bh;
1470
1471 if (IS_ERR(ce)) {
1472 if (PTR_ERR(ce) == -EAGAIN)
1473 goto again;
1474 break;
1475 }
1476 bh = sb_bread(inode->i_sb, ce->e_block);
1477 if (!bh) {
Mingming Cao617ba132006-10-11 01:20:53 -07001478 ext4_error(inode->i_sb, __FUNCTION__,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001479 "inode %lu: block %lu read error",
1480 inode->i_ino, (unsigned long) ce->e_block);
1481 } else if (le32_to_cpu(BHDR(bh)->h_refcount) >=
Mingming Cao617ba132006-10-11 01:20:53 -07001482 EXT4_XATTR_REFCOUNT_MAX) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001483 ea_idebug(inode, "block %lu refcount %d>=%d",
1484 (unsigned long) ce->e_block,
1485 le32_to_cpu(BHDR(bh)->h_refcount),
Mingming Cao617ba132006-10-11 01:20:53 -07001486 EXT4_XATTR_REFCOUNT_MAX);
1487 } else if (ext4_xattr_cmp(header, BHDR(bh)) == 0) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001488 *pce = ce;
1489 return bh;
1490 }
1491 brelse(bh);
1492 ce = mb_cache_entry_find_next(ce, 0, inode->i_sb->s_bdev, hash);
1493 }
1494 return NULL;
1495}
1496
1497#define NAME_HASH_SHIFT 5
1498#define VALUE_HASH_SHIFT 16
1499
1500/*
Mingming Cao617ba132006-10-11 01:20:53 -07001501 * ext4_xattr_hash_entry()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001502 *
1503 * Compute the hash of an extended attribute.
1504 */
Mingming Cao617ba132006-10-11 01:20:53 -07001505static inline void ext4_xattr_hash_entry(struct ext4_xattr_header *header,
1506 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001507{
1508 __u32 hash = 0;
1509 char *name = entry->e_name;
1510 int n;
1511
1512 for (n=0; n < entry->e_name_len; n++) {
1513 hash = (hash << NAME_HASH_SHIFT) ^
1514 (hash >> (8*sizeof(hash) - NAME_HASH_SHIFT)) ^
1515 *name++;
1516 }
1517
1518 if (entry->e_value_block == 0 && entry->e_value_size != 0) {
1519 __le32 *value = (__le32 *)((char *)header +
1520 le16_to_cpu(entry->e_value_offs));
1521 for (n = (le32_to_cpu(entry->e_value_size) +
Mingming Cao617ba132006-10-11 01:20:53 -07001522 EXT4_XATTR_ROUND) >> EXT4_XATTR_PAD_BITS; n; n--) {
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001523 hash = (hash << VALUE_HASH_SHIFT) ^
1524 (hash >> (8*sizeof(hash) - VALUE_HASH_SHIFT)) ^
1525 le32_to_cpu(*value++);
1526 }
1527 }
1528 entry->e_hash = cpu_to_le32(hash);
1529}
1530
1531#undef NAME_HASH_SHIFT
1532#undef VALUE_HASH_SHIFT
1533
1534#define BLOCK_HASH_SHIFT 16
1535
1536/*
Mingming Cao617ba132006-10-11 01:20:53 -07001537 * ext4_xattr_rehash()
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001538 *
1539 * Re-compute the extended attribute hash value after an entry has changed.
1540 */
Mingming Cao617ba132006-10-11 01:20:53 -07001541static void ext4_xattr_rehash(struct ext4_xattr_header *header,
1542 struct ext4_xattr_entry *entry)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001543{
Mingming Cao617ba132006-10-11 01:20:53 -07001544 struct ext4_xattr_entry *here;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001545 __u32 hash = 0;
1546
Mingming Cao617ba132006-10-11 01:20:53 -07001547 ext4_xattr_hash_entry(header, entry);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001548 here = ENTRY(header+1);
1549 while (!IS_LAST_ENTRY(here)) {
1550 if (!here->e_hash) {
1551 /* Block is not shared if an entry's hash value == 0 */
1552 hash = 0;
1553 break;
1554 }
1555 hash = (hash << BLOCK_HASH_SHIFT) ^
1556 (hash >> (8*sizeof(hash) - BLOCK_HASH_SHIFT)) ^
1557 le32_to_cpu(here->e_hash);
Mingming Cao617ba132006-10-11 01:20:53 -07001558 here = EXT4_XATTR_NEXT(here);
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001559 }
1560 header->h_hash = cpu_to_le32(hash);
1561}
1562
1563#undef BLOCK_HASH_SHIFT
1564
1565int __init
Mingming Cao617ba132006-10-11 01:20:53 -07001566init_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001567{
Mingming Cao617ba132006-10-11 01:20:53 -07001568 ext4_xattr_cache = mb_cache_create("ext4_xattr", NULL,
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001569 sizeof(struct mb_cache_entry) +
1570 sizeof(((struct mb_cache_entry *) 0)->e_indexes[0]), 1, 6);
Mingming Cao617ba132006-10-11 01:20:53 -07001571 if (!ext4_xattr_cache)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001572 return -ENOMEM;
1573 return 0;
1574}
1575
1576void
Mingming Cao617ba132006-10-11 01:20:53 -07001577exit_ext4_xattr(void)
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001578{
Mingming Cao617ba132006-10-11 01:20:53 -07001579 if (ext4_xattr_cache)
1580 mb_cache_destroy(ext4_xattr_cache);
1581 ext4_xattr_cache = NULL;
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001582}