blob: 9ae6e67090cdfad1bd52a7e7169ba725dea19c82 [file] [log] [blame]
Alex Tomasa86c6182006-10-11 01:21:03 -07001/*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public Licens
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23/*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32#include <linux/module.h>
33#include <linux/fs.h>
34#include <linux/time.h>
35#include <linux/ext4_jbd2.h>
Mingming Caocd02ff02007-10-16 18:38:25 -040036#include <linux/jbd2.h>
Alex Tomasa86c6182006-10-11 01:21:03 -070037#include <linux/highuid.h>
38#include <linux/pagemap.h>
39#include <linux/quotaops.h>
40#include <linux/string.h>
41#include <linux/slab.h>
Amit Aroraa2df2a62007-07-17 21:42:41 -040042#include <linux/falloc.h>
Alex Tomasa86c6182006-10-11 01:21:03 -070043#include <linux/ext4_fs_extents.h>
44#include <asm/uaccess.h>
45
46
Randy Dunlapd0d856e2006-10-11 01:21:07 -070047/*
48 * ext_pblock:
49 * combine low and high parts of physical block number into ext4_fsblk_t
50 */
Avantika Mathur09b88252006-12-06 20:41:36 -080051static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070052{
53 ext4_fsblk_t block;
54
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -040055 block = le32_to_cpu(ex->ee_start_lo);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070056 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070057 return block;
58}
59
Randy Dunlapd0d856e2006-10-11 01:21:07 -070060/*
61 * idx_pblock:
62 * combine low and high parts of a leaf physical block number into ext4_fsblk_t
63 */
Aneesh Kumar K.Vc14c6fd2008-01-28 23:58:26 -050064ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070065{
66 ext4_fsblk_t block;
67
Aneesh Kumar K.Vd8dd0b42007-10-16 18:38:25 -040068 block = le32_to_cpu(ix->ei_leaf_lo);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070069 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070070 return block;
71}
72
Randy Dunlapd0d856e2006-10-11 01:21:07 -070073/*
74 * ext4_ext_store_pblock:
75 * stores a large physical block number into an extent struct,
76 * breaking it into parts
77 */
Aneesh Kumar K.Vc14c6fd2008-01-28 23:58:26 -050078void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070079{
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -040080 ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070081 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070082}
83
Randy Dunlapd0d856e2006-10-11 01:21:07 -070084/*
85 * ext4_idx_store_pblock:
86 * stores a large physical block number into an index struct,
87 * breaking it into parts
88 */
Avantika Mathur09b88252006-12-06 20:41:36 -080089static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070090{
Aneesh Kumar K.Vd8dd0b42007-10-16 18:38:25 -040091 ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070092 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070093}
94
Alex Tomasa86c6182006-10-11 01:21:03 -070095static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed)
96{
97 int err;
98
99 if (handle->h_buffer_credits > needed)
100 return handle;
101 if (!ext4_journal_extend(handle, needed))
102 return handle;
103 err = ext4_journal_restart(handle, needed);
104
105 return handle;
106}
107
108/*
109 * could return:
110 * - EROFS
111 * - ENOMEM
112 */
113static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
114 struct ext4_ext_path *path)
115{
116 if (path->p_bh) {
117 /* path points to block */
118 return ext4_journal_get_write_access(handle, path->p_bh);
119 }
120 /* path points to leaf/index in inode body */
121 /* we use in-core data, no need to protect them */
122 return 0;
123}
124
125/*
126 * could return:
127 * - EROFS
128 * - ENOMEM
129 * - EIO
130 */
131static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
132 struct ext4_ext_path *path)
133{
134 int err;
135 if (path->p_bh) {
136 /* path points to block */
137 err = ext4_journal_dirty_metadata(handle, path->p_bh);
138 } else {
139 /* path points to leaf/index in inode body */
140 err = ext4_mark_inode_dirty(handle, inode);
141 }
142 return err;
143}
144
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700145static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700146 struct ext4_ext_path *path,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500147 ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700148{
149 struct ext4_inode_info *ei = EXT4_I(inode);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700150 ext4_fsblk_t bg_start;
Valerie Clement74d34872008-02-15 13:43:07 -0500151 ext4_fsblk_t last_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700152 ext4_grpblk_t colour;
Alex Tomasa86c6182006-10-11 01:21:03 -0700153 int depth;
154
155 if (path) {
156 struct ext4_extent *ex;
157 depth = path->p_depth;
158
159 /* try to predict block placement */
Avantika Mathur7e028972006-12-06 20:41:33 -0800160 ex = path[depth].p_ext;
161 if (ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700162 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700163
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700164 /* it looks like index is empty;
165 * try to find starting block from index itself */
Alex Tomasa86c6182006-10-11 01:21:03 -0700166 if (path[depth].p_bh)
167 return path[depth].p_bh->b_blocknr;
168 }
169
170 /* OK. use inode's group */
171 bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) +
172 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block);
Valerie Clement74d34872008-02-15 13:43:07 -0500173 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
174
175 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
176 colour = (current->pid % 16) *
Alex Tomasa86c6182006-10-11 01:21:03 -0700177 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
Valerie Clement74d34872008-02-15 13:43:07 -0500178 else
179 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
Alex Tomasa86c6182006-10-11 01:21:03 -0700180 return bg_start + colour + block;
181}
182
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700183static ext4_fsblk_t
Alex Tomasa86c6182006-10-11 01:21:03 -0700184ext4_ext_new_block(handle_t *handle, struct inode *inode,
185 struct ext4_ext_path *path,
186 struct ext4_extent *ex, int *err)
187{
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700188 ext4_fsblk_t goal, newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700189
190 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
191 newblock = ext4_new_block(handle, inode, goal, err);
192 return newblock;
193}
194
Avantika Mathur09b88252006-12-06 20:41:36 -0800195static int ext4_ext_space_block(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700196{
197 int size;
198
199 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
200 / sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100201#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700202 if (size > 6)
203 size = 6;
204#endif
205 return size;
206}
207
Avantika Mathur09b88252006-12-06 20:41:36 -0800208static int ext4_ext_space_block_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700209{
210 int size;
211
212 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
213 / sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100214#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700215 if (size > 5)
216 size = 5;
217#endif
218 return size;
219}
220
Avantika Mathur09b88252006-12-06 20:41:36 -0800221static int ext4_ext_space_root(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700222{
223 int size;
224
225 size = sizeof(EXT4_I(inode)->i_data);
226 size -= sizeof(struct ext4_extent_header);
227 size /= sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100228#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700229 if (size > 3)
230 size = 3;
231#endif
232 return size;
233}
234
Avantika Mathur09b88252006-12-06 20:41:36 -0800235static int ext4_ext_space_root_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700236{
237 int size;
238
239 size = sizeof(EXT4_I(inode)->i_data);
240 size -= sizeof(struct ext4_extent_header);
241 size /= sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100242#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700243 if (size > 4)
244 size = 4;
245#endif
246 return size;
247}
248
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400249static int
250ext4_ext_max_entries(struct inode *inode, int depth)
251{
252 int max;
253
254 if (depth == ext_depth(inode)) {
255 if (depth == 0)
256 max = ext4_ext_space_root(inode);
257 else
258 max = ext4_ext_space_root_idx(inode);
259 } else {
260 if (depth == 0)
261 max = ext4_ext_space_block(inode);
262 else
263 max = ext4_ext_space_block_idx(inode);
264 }
265
266 return max;
267}
268
269static int __ext4_ext_check_header(const char *function, struct inode *inode,
270 struct ext4_extent_header *eh,
271 int depth)
272{
273 const char *error_msg;
274 int max = 0;
275
276 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
277 error_msg = "invalid magic";
278 goto corrupted;
279 }
280 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
281 error_msg = "unexpected eh_depth";
282 goto corrupted;
283 }
284 if (unlikely(eh->eh_max == 0)) {
285 error_msg = "invalid eh_max";
286 goto corrupted;
287 }
288 max = ext4_ext_max_entries(inode, depth);
289 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
290 error_msg = "too large eh_max";
291 goto corrupted;
292 }
293 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
294 error_msg = "invalid eh_entries";
295 goto corrupted;
296 }
297 return 0;
298
299corrupted:
300 ext4_error(inode->i_sb, function,
301 "bad header in inode #%lu: %s - magic %x, "
302 "entries %u, max %u(%u), depth %u(%u)",
303 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
304 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
305 max, le16_to_cpu(eh->eh_depth), depth);
306
307 return -EIO;
308}
309
310#define ext4_ext_check_header(inode, eh, depth) \
311 __ext4_ext_check_header(__FUNCTION__, inode, eh, depth)
312
Alex Tomasa86c6182006-10-11 01:21:03 -0700313#ifdef EXT_DEBUG
314static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
315{
316 int k, l = path->p_depth;
317
318 ext_debug("path:");
319 for (k = 0; k <= l; k++, path++) {
320 if (path->p_idx) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700321 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700322 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700323 } else if (path->p_ext) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700324 ext_debug(" %d:%d:%llu ",
Alex Tomasa86c6182006-10-11 01:21:03 -0700325 le32_to_cpu(path->p_ext->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400326 ext4_ext_get_actual_len(path->p_ext),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700327 ext_pblock(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700328 } else
329 ext_debug(" []");
330 }
331 ext_debug("\n");
332}
333
334static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
335{
336 int depth = ext_depth(inode);
337 struct ext4_extent_header *eh;
338 struct ext4_extent *ex;
339 int i;
340
341 if (!path)
342 return;
343
344 eh = path[depth].p_hdr;
345 ex = EXT_FIRST_EXTENT(eh);
346
347 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700348 ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400349 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -0700350 }
351 ext_debug("\n");
352}
353#else
354#define ext4_ext_show_path(inode,path)
355#define ext4_ext_show_leaf(inode,path)
356#endif
357
Aneesh Kumar K.Vb35905c2008-02-25 16:54:37 -0500358void ext4_ext_drop_refs(struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700359{
360 int depth = path->p_depth;
361 int i;
362
363 for (i = 0; i <= depth; i++, path++)
364 if (path->p_bh) {
365 brelse(path->p_bh);
366 path->p_bh = NULL;
367 }
368}
369
370/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700371 * ext4_ext_binsearch_idx:
372 * binary search for the closest index of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400373 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700374 */
375static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500376ext4_ext_binsearch_idx(struct inode *inode,
377 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700378{
379 struct ext4_extent_header *eh = path->p_hdr;
380 struct ext4_extent_idx *r, *l, *m;
381
Alex Tomasa86c6182006-10-11 01:21:03 -0700382
Eric Sandeenbba90742008-01-28 23:58:27 -0500383 ext_debug("binsearch for %u(idx): ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700384
385 l = EXT_FIRST_INDEX(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400386 r = EXT_LAST_INDEX(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700387 while (l <= r) {
388 m = l + (r - l) / 2;
389 if (block < le32_to_cpu(m->ei_block))
390 r = m - 1;
391 else
392 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400393 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
394 m, le32_to_cpu(m->ei_block),
395 r, le32_to_cpu(r->ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700396 }
397
398 path->p_idx = l - 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700399 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400400 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700401
402#ifdef CHECK_BINSEARCH
403 {
404 struct ext4_extent_idx *chix, *ix;
405 int k;
406
407 chix = ix = EXT_FIRST_INDEX(eh);
408 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
409 if (k != 0 &&
410 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
411 printk("k=%d, ix=0x%p, first=0x%p\n", k,
412 ix, EXT_FIRST_INDEX(eh));
413 printk("%u <= %u\n",
414 le32_to_cpu(ix->ei_block),
415 le32_to_cpu(ix[-1].ei_block));
416 }
417 BUG_ON(k && le32_to_cpu(ix->ei_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400418 <= le32_to_cpu(ix[-1].ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700419 if (block < le32_to_cpu(ix->ei_block))
420 break;
421 chix = ix;
422 }
423 BUG_ON(chix != path->p_idx);
424 }
425#endif
426
427}
428
429/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700430 * ext4_ext_binsearch:
431 * binary search for closest extent of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400432 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700433 */
434static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500435ext4_ext_binsearch(struct inode *inode,
436 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700437{
438 struct ext4_extent_header *eh = path->p_hdr;
439 struct ext4_extent *r, *l, *m;
440
Alex Tomasa86c6182006-10-11 01:21:03 -0700441 if (eh->eh_entries == 0) {
442 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700443 * this leaf is empty:
444 * we get such a leaf in split/add case
Alex Tomasa86c6182006-10-11 01:21:03 -0700445 */
446 return;
447 }
448
Eric Sandeenbba90742008-01-28 23:58:27 -0500449 ext_debug("binsearch for %u: ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700450
451 l = EXT_FIRST_EXTENT(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400452 r = EXT_LAST_EXTENT(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700453
454 while (l <= r) {
455 m = l + (r - l) / 2;
456 if (block < le32_to_cpu(m->ee_block))
457 r = m - 1;
458 else
459 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400460 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
461 m, le32_to_cpu(m->ee_block),
462 r, le32_to_cpu(r->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700463 }
464
465 path->p_ext = l - 1;
Mingming Cao2ae02102006-10-11 01:21:11 -0700466 ext_debug(" -> %d:%llu:%d ",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400467 le32_to_cpu(path->p_ext->ee_block),
468 ext_pblock(path->p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400469 ext4_ext_get_actual_len(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700470
471#ifdef CHECK_BINSEARCH
472 {
473 struct ext4_extent *chex, *ex;
474 int k;
475
476 chex = ex = EXT_FIRST_EXTENT(eh);
477 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
478 BUG_ON(k && le32_to_cpu(ex->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400479 <= le32_to_cpu(ex[-1].ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700480 if (block < le32_to_cpu(ex->ee_block))
481 break;
482 chex = ex;
483 }
484 BUG_ON(chex != path->p_ext);
485 }
486#endif
487
488}
489
490int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
491{
492 struct ext4_extent_header *eh;
493
494 eh = ext_inode_hdr(inode);
495 eh->eh_depth = 0;
496 eh->eh_entries = 0;
497 eh->eh_magic = EXT4_EXT_MAGIC;
498 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
499 ext4_mark_inode_dirty(handle, inode);
500 ext4_ext_invalidate_cache(inode);
501 return 0;
502}
503
504struct ext4_ext_path *
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500505ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
506 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700507{
508 struct ext4_extent_header *eh;
509 struct buffer_head *bh;
510 short int depth, i, ppos = 0, alloc = 0;
511
512 eh = ext_inode_hdr(inode);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400513 depth = ext_depth(inode);
514 if (ext4_ext_check_header(inode, eh, depth))
Alex Tomasa86c6182006-10-11 01:21:03 -0700515 return ERR_PTR(-EIO);
516
Alex Tomasa86c6182006-10-11 01:21:03 -0700517
518 /* account possible depth increase */
519 if (!path) {
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800520 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
Alex Tomasa86c6182006-10-11 01:21:03 -0700521 GFP_NOFS);
522 if (!path)
523 return ERR_PTR(-ENOMEM);
524 alloc = 1;
525 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700526 path[0].p_hdr = eh;
527
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400528 i = depth;
Alex Tomasa86c6182006-10-11 01:21:03 -0700529 /* walk through the tree */
530 while (i) {
531 ext_debug("depth %d: num %d, max %d\n",
532 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400533
Alex Tomasa86c6182006-10-11 01:21:03 -0700534 ext4_ext_binsearch_idx(inode, path + ppos, block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700535 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -0700536 path[ppos].p_depth = i;
537 path[ppos].p_ext = NULL;
538
539 bh = sb_bread(inode->i_sb, path[ppos].p_block);
540 if (!bh)
541 goto err;
542
543 eh = ext_block_hdr(bh);
544 ppos++;
545 BUG_ON(ppos > depth);
546 path[ppos].p_bh = bh;
547 path[ppos].p_hdr = eh;
548 i--;
549
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400550 if (ext4_ext_check_header(inode, eh, i))
Alex Tomasa86c6182006-10-11 01:21:03 -0700551 goto err;
552 }
553
554 path[ppos].p_depth = i;
555 path[ppos].p_hdr = eh;
556 path[ppos].p_ext = NULL;
557 path[ppos].p_idx = NULL;
558
Alex Tomasa86c6182006-10-11 01:21:03 -0700559 /* find extent */
560 ext4_ext_binsearch(inode, path + ppos, block);
561
562 ext4_ext_show_path(inode, path);
563
564 return path;
565
566err:
567 ext4_ext_drop_refs(path);
568 if (alloc)
569 kfree(path);
570 return ERR_PTR(-EIO);
571}
572
573/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700574 * ext4_ext_insert_index:
575 * insert new index [@logical;@ptr] into the block at @curp;
576 * check where to insert: before @curp or after @curp
Alex Tomasa86c6182006-10-11 01:21:03 -0700577 */
578static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
579 struct ext4_ext_path *curp,
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700580 int logical, ext4_fsblk_t ptr)
Alex Tomasa86c6182006-10-11 01:21:03 -0700581{
582 struct ext4_extent_idx *ix;
583 int len, err;
584
Avantika Mathur7e028972006-12-06 20:41:33 -0800585 err = ext4_ext_get_access(handle, inode, curp);
586 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700587 return err;
588
589 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
590 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
591 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
592 /* insert after */
593 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
594 len = (len - 1) * sizeof(struct ext4_extent_idx);
595 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400596 ext_debug("insert new index %d after: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700597 "move %d from 0x%p to 0x%p\n",
598 logical, ptr, len,
599 (curp->p_idx + 1), (curp->p_idx + 2));
600 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
601 }
602 ix = curp->p_idx + 1;
603 } else {
604 /* insert before */
605 len = len * sizeof(struct ext4_extent_idx);
606 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400607 ext_debug("insert new index %d before: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700608 "move %d from 0x%p to 0x%p\n",
609 logical, ptr, len,
610 curp->p_idx, (curp->p_idx + 1));
611 memmove(curp->p_idx + 1, curp->p_idx, len);
612 ix = curp->p_idx;
613 }
614
615 ix->ei_block = cpu_to_le32(logical);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700616 ext4_idx_store_pblock(ix, ptr);
Alex Tomasa86c6182006-10-11 01:21:03 -0700617 curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1);
618
619 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400620 > le16_to_cpu(curp->p_hdr->eh_max));
Alex Tomasa86c6182006-10-11 01:21:03 -0700621 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
622
623 err = ext4_ext_dirty(handle, inode, curp);
624 ext4_std_error(inode->i_sb, err);
625
626 return err;
627}
628
629/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700630 * ext4_ext_split:
631 * inserts new subtree into the path, using free index entry
632 * at depth @at:
633 * - allocates all needed blocks (new leaf and all intermediate index blocks)
634 * - makes decision where to split
635 * - moves remaining extents and index entries (right to the split point)
636 * into the newly allocated blocks
637 * - initializes subtree
Alex Tomasa86c6182006-10-11 01:21:03 -0700638 */
639static int ext4_ext_split(handle_t *handle, struct inode *inode,
640 struct ext4_ext_path *path,
641 struct ext4_extent *newext, int at)
642{
643 struct buffer_head *bh = NULL;
644 int depth = ext_depth(inode);
645 struct ext4_extent_header *neh;
646 struct ext4_extent_idx *fidx;
647 struct ext4_extent *ex;
648 int i = at, k, m, a;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700649 ext4_fsblk_t newblock, oldblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700650 __le32 border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700651 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
Alex Tomasa86c6182006-10-11 01:21:03 -0700652 int err = 0;
653
654 /* make decision: where to split? */
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700655 /* FIXME: now decision is simplest: at current extent */
Alex Tomasa86c6182006-10-11 01:21:03 -0700656
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700657 /* if current leaf will be split, then we should use
Alex Tomasa86c6182006-10-11 01:21:03 -0700658 * border from split point */
659 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));
660 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
661 border = path[depth].p_ext[1].ee_block;
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700662 ext_debug("leaf will be split."
Alex Tomasa86c6182006-10-11 01:21:03 -0700663 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400664 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700665 } else {
666 border = newext->ee_block;
667 ext_debug("leaf will be added."
668 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400669 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700670 }
671
672 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700673 * If error occurs, then we break processing
674 * and mark filesystem read-only. index won't
Alex Tomasa86c6182006-10-11 01:21:03 -0700675 * be inserted and tree will be in consistent
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700676 * state. Next mount will repair buffers too.
Alex Tomasa86c6182006-10-11 01:21:03 -0700677 */
678
679 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700680 * Get array to track all allocated blocks.
681 * We need this to handle errors and free blocks
682 * upon them.
Alex Tomasa86c6182006-10-11 01:21:03 -0700683 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800684 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -0700685 if (!ablocks)
686 return -ENOMEM;
Alex Tomasa86c6182006-10-11 01:21:03 -0700687
688 /* allocate all needed blocks */
689 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
690 for (a = 0; a < depth - at; a++) {
691 newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
692 if (newblock == 0)
693 goto cleanup;
694 ablocks[a] = newblock;
695 }
696
697 /* initialize new leaf */
698 newblock = ablocks[--a];
699 BUG_ON(newblock == 0);
700 bh = sb_getblk(inode->i_sb, newblock);
701 if (!bh) {
702 err = -EIO;
703 goto cleanup;
704 }
705 lock_buffer(bh);
706
Avantika Mathur7e028972006-12-06 20:41:33 -0800707 err = ext4_journal_get_create_access(handle, bh);
708 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700709 goto cleanup;
710
711 neh = ext_block_hdr(bh);
712 neh->eh_entries = 0;
713 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
714 neh->eh_magic = EXT4_EXT_MAGIC;
715 neh->eh_depth = 0;
716 ex = EXT_FIRST_EXTENT(neh);
717
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700718 /* move remainder of path[depth] to the new leaf */
Alex Tomasa86c6182006-10-11 01:21:03 -0700719 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);
720 /* start copy from next extent */
721 /* TODO: we could do it by single memmove */
722 m = 0;
723 path[depth].p_ext++;
724 while (path[depth].p_ext <=
725 EXT_MAX_EXTENT(path[depth].p_hdr)) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700726 ext_debug("move %d:%llu:%d in new leaf %llu\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400727 le32_to_cpu(path[depth].p_ext->ee_block),
728 ext_pblock(path[depth].p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400729 ext4_ext_get_actual_len(path[depth].p_ext),
Alex Tomasa86c6182006-10-11 01:21:03 -0700730 newblock);
731 /*memmove(ex++, path[depth].p_ext++,
732 sizeof(struct ext4_extent));
733 neh->eh_entries++;*/
734 path[depth].p_ext++;
735 m++;
736 }
737 if (m) {
738 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
739 neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m);
740 }
741
742 set_buffer_uptodate(bh);
743 unlock_buffer(bh);
744
Avantika Mathur7e028972006-12-06 20:41:33 -0800745 err = ext4_journal_dirty_metadata(handle, bh);
746 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700747 goto cleanup;
748 brelse(bh);
749 bh = NULL;
750
751 /* correct old leaf */
752 if (m) {
Avantika Mathur7e028972006-12-06 20:41:33 -0800753 err = ext4_ext_get_access(handle, inode, path + depth);
754 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700755 goto cleanup;
756 path[depth].p_hdr->eh_entries =
757 cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m);
Avantika Mathur7e028972006-12-06 20:41:33 -0800758 err = ext4_ext_dirty(handle, inode, path + depth);
759 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700760 goto cleanup;
761
762 }
763
764 /* create intermediate indexes */
765 k = depth - at - 1;
766 BUG_ON(k < 0);
767 if (k)
768 ext_debug("create %d intermediate indices\n", k);
769 /* insert new index into current index block */
770 /* current depth stored in i var */
771 i = depth - 1;
772 while (k--) {
773 oldblock = newblock;
774 newblock = ablocks[--a];
Eric Sandeenbba90742008-01-28 23:58:27 -0500775 bh = sb_getblk(inode->i_sb, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700776 if (!bh) {
777 err = -EIO;
778 goto cleanup;
779 }
780 lock_buffer(bh);
781
Avantika Mathur7e028972006-12-06 20:41:33 -0800782 err = ext4_journal_get_create_access(handle, bh);
783 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700784 goto cleanup;
785
786 neh = ext_block_hdr(bh);
787 neh->eh_entries = cpu_to_le16(1);
788 neh->eh_magic = EXT4_EXT_MAGIC;
789 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
790 neh->eh_depth = cpu_to_le16(depth - i);
791 fidx = EXT_FIRST_INDEX(neh);
792 fidx->ei_block = border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700793 ext4_idx_store_pblock(fidx, oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700794
Eric Sandeenbba90742008-01-28 23:58:27 -0500795 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
796 i, newblock, le32_to_cpu(border), oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700797 /* copy indexes */
798 m = 0;
799 path[i].p_idx++;
800
801 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
802 EXT_MAX_INDEX(path[i].p_hdr));
803 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
804 EXT_LAST_INDEX(path[i].p_hdr));
805 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400806 ext_debug("%d: move %d:%llu in new index %llu\n", i,
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400807 le32_to_cpu(path[i].p_idx->ei_block),
808 idx_pblock(path[i].p_idx),
809 newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700810 /*memmove(++fidx, path[i].p_idx++,
811 sizeof(struct ext4_extent_idx));
812 neh->eh_entries++;
813 BUG_ON(neh->eh_entries > neh->eh_max);*/
814 path[i].p_idx++;
815 m++;
816 }
817 if (m) {
818 memmove(++fidx, path[i].p_idx - m,
819 sizeof(struct ext4_extent_idx) * m);
820 neh->eh_entries =
821 cpu_to_le16(le16_to_cpu(neh->eh_entries) + m);
822 }
823 set_buffer_uptodate(bh);
824 unlock_buffer(bh);
825
Avantika Mathur7e028972006-12-06 20:41:33 -0800826 err = ext4_journal_dirty_metadata(handle, bh);
827 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700828 goto cleanup;
829 brelse(bh);
830 bh = NULL;
831
832 /* correct old index */
833 if (m) {
834 err = ext4_ext_get_access(handle, inode, path + i);
835 if (err)
836 goto cleanup;
837 path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m);
838 err = ext4_ext_dirty(handle, inode, path + i);
839 if (err)
840 goto cleanup;
841 }
842
843 i--;
844 }
845
846 /* insert new index */
Alex Tomasa86c6182006-10-11 01:21:03 -0700847 err = ext4_ext_insert_index(handle, inode, path + at,
848 le32_to_cpu(border), newblock);
849
850cleanup:
851 if (bh) {
852 if (buffer_locked(bh))
853 unlock_buffer(bh);
854 brelse(bh);
855 }
856
857 if (err) {
858 /* free all allocated blocks in error case */
859 for (i = 0; i < depth; i++) {
860 if (!ablocks[i])
861 continue;
Alex Tomasc9de5602008-01-29 00:19:52 -0500862 ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -0700863 }
864 }
865 kfree(ablocks);
866
867 return err;
868}
869
870/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700871 * ext4_ext_grow_indepth:
872 * implements tree growing procedure:
873 * - allocates new block
874 * - moves top-level data (index block or leaf) into the new block
875 * - initializes new top-level, creating index that points to the
876 * just created block
Alex Tomasa86c6182006-10-11 01:21:03 -0700877 */
878static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
879 struct ext4_ext_path *path,
880 struct ext4_extent *newext)
881{
882 struct ext4_ext_path *curp = path;
883 struct ext4_extent_header *neh;
884 struct ext4_extent_idx *fidx;
885 struct buffer_head *bh;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700886 ext4_fsblk_t newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700887 int err = 0;
888
889 newblock = ext4_ext_new_block(handle, inode, path, newext, &err);
890 if (newblock == 0)
891 return err;
892
893 bh = sb_getblk(inode->i_sb, newblock);
894 if (!bh) {
895 err = -EIO;
896 ext4_std_error(inode->i_sb, err);
897 return err;
898 }
899 lock_buffer(bh);
900
Avantika Mathur7e028972006-12-06 20:41:33 -0800901 err = ext4_journal_get_create_access(handle, bh);
902 if (err) {
Alex Tomasa86c6182006-10-11 01:21:03 -0700903 unlock_buffer(bh);
904 goto out;
905 }
906
907 /* move top-level index/leaf into new block */
908 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
909
910 /* set size of new block */
911 neh = ext_block_hdr(bh);
912 /* old root could have indexes or leaves
913 * so calculate e_max right way */
914 if (ext_depth(inode))
915 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
916 else
917 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
918 neh->eh_magic = EXT4_EXT_MAGIC;
919 set_buffer_uptodate(bh);
920 unlock_buffer(bh);
921
Avantika Mathur7e028972006-12-06 20:41:33 -0800922 err = ext4_journal_dirty_metadata(handle, bh);
923 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700924 goto out;
925
926 /* create index in new top-level index: num,max,pointer */
Avantika Mathur7e028972006-12-06 20:41:33 -0800927 err = ext4_ext_get_access(handle, inode, curp);
928 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700929 goto out;
930
931 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
932 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
933 curp->p_hdr->eh_entries = cpu_to_le16(1);
934 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400935
936 if (path[0].p_hdr->eh_depth)
937 curp->p_idx->ei_block =
938 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
939 else
940 curp->p_idx->ei_block =
941 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700942 ext4_idx_store_pblock(curp->p_idx, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700943
944 neh = ext_inode_hdr(inode);
945 fidx = EXT_FIRST_INDEX(neh);
Mingming Cao2ae02102006-10-11 01:21:11 -0700946 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -0700947 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700948 le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700949
950 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
951 err = ext4_ext_dirty(handle, inode, curp);
952out:
953 brelse(bh);
954
955 return err;
956}
957
958/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700959 * ext4_ext_create_new_leaf:
960 * finds empty index and adds new leaf.
961 * if no free index is found, then it requests in-depth growing.
Alex Tomasa86c6182006-10-11 01:21:03 -0700962 */
963static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
964 struct ext4_ext_path *path,
965 struct ext4_extent *newext)
966{
967 struct ext4_ext_path *curp;
968 int depth, i, err = 0;
969
970repeat:
971 i = depth = ext_depth(inode);
972
973 /* walk up to the tree and look for free index entry */
974 curp = path + depth;
975 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
976 i--;
977 curp--;
978 }
979
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700980 /* we use already allocated block for index block,
981 * so subsequent data blocks should be contiguous */
Alex Tomasa86c6182006-10-11 01:21:03 -0700982 if (EXT_HAS_FREE_INDEX(curp)) {
983 /* if we found index with free entry, then use that
984 * entry: create all needed subtree and add new leaf */
985 err = ext4_ext_split(handle, inode, path, newext, i);
986
987 /* refill path */
988 ext4_ext_drop_refs(path);
989 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500990 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
991 path);
Alex Tomasa86c6182006-10-11 01:21:03 -0700992 if (IS_ERR(path))
993 err = PTR_ERR(path);
994 } else {
995 /* tree is full, time to grow in depth */
996 err = ext4_ext_grow_indepth(handle, inode, path, newext);
997 if (err)
998 goto out;
999
1000 /* refill path */
1001 ext4_ext_drop_refs(path);
1002 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001003 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1004 path);
Alex Tomasa86c6182006-10-11 01:21:03 -07001005 if (IS_ERR(path)) {
1006 err = PTR_ERR(path);
1007 goto out;
1008 }
1009
1010 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001011 * only first (depth 0 -> 1) produces free space;
1012 * in all other cases we have to split the grown tree
Alex Tomasa86c6182006-10-11 01:21:03 -07001013 */
1014 depth = ext_depth(inode);
1015 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001016 /* now we need to split */
Alex Tomasa86c6182006-10-11 01:21:03 -07001017 goto repeat;
1018 }
1019 }
1020
1021out:
1022 return err;
1023}
1024
1025/*
Alex Tomas1988b512008-01-28 23:58:27 -05001026 * search the closest allocated block to the left for *logical
1027 * and returns it at @logical + it's physical address at @phys
1028 * if *logical is the smallest allocated block, the function
1029 * returns 0 at @phys
1030 * return value contains 0 (success) or error code
1031 */
1032int
1033ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
1034 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1035{
1036 struct ext4_extent_idx *ix;
1037 struct ext4_extent *ex;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001038 int depth, ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001039
1040 BUG_ON(path == NULL);
1041 depth = path->p_depth;
1042 *phys = 0;
1043
1044 if (depth == 0 && path->p_ext == NULL)
1045 return 0;
1046
1047 /* usually extent in the path covers blocks smaller
1048 * then *logical, but it can be that extent is the
1049 * first one in the file */
1050
1051 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001052 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001053 if (*logical < le32_to_cpu(ex->ee_block)) {
1054 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1055 while (--depth >= 0) {
1056 ix = path[depth].p_idx;
1057 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1058 }
1059 return 0;
1060 }
1061
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001062 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001063
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001064 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1065 *phys = ext_pblock(ex) + ee_len - 1;
Alex Tomas1988b512008-01-28 23:58:27 -05001066 return 0;
1067}
1068
1069/*
1070 * search the closest allocated block to the right for *logical
1071 * and returns it at @logical + it's physical address at @phys
1072 * if *logical is the smallest allocated block, the function
1073 * returns 0 at @phys
1074 * return value contains 0 (success) or error code
1075 */
1076int
1077ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
1078 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1079{
1080 struct buffer_head *bh = NULL;
1081 struct ext4_extent_header *eh;
1082 struct ext4_extent_idx *ix;
1083 struct ext4_extent *ex;
1084 ext4_fsblk_t block;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001085 int depth, ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001086
1087 BUG_ON(path == NULL);
1088 depth = path->p_depth;
1089 *phys = 0;
1090
1091 if (depth == 0 && path->p_ext == NULL)
1092 return 0;
1093
1094 /* usually extent in the path covers blocks smaller
1095 * then *logical, but it can be that extent is the
1096 * first one in the file */
1097
1098 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001099 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001100 if (*logical < le32_to_cpu(ex->ee_block)) {
1101 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1102 while (--depth >= 0) {
1103 ix = path[depth].p_idx;
1104 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1105 }
1106 *logical = le32_to_cpu(ex->ee_block);
1107 *phys = ext_pblock(ex);
1108 return 0;
1109 }
1110
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001111 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001112
1113 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1114 /* next allocated block in this leaf */
1115 ex++;
1116 *logical = le32_to_cpu(ex->ee_block);
1117 *phys = ext_pblock(ex);
1118 return 0;
1119 }
1120
1121 /* go up and search for index to the right */
1122 while (--depth >= 0) {
1123 ix = path[depth].p_idx;
1124 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1125 break;
1126 }
1127
1128 if (depth < 0) {
1129 /* we've gone up to the root and
1130 * found no index to the right */
1131 return 0;
1132 }
1133
1134 /* we've found index to the right, let's
1135 * follow it and find the closest allocated
1136 * block to the right */
1137 ix++;
1138 block = idx_pblock(ix);
1139 while (++depth < path->p_depth) {
1140 bh = sb_bread(inode->i_sb, block);
1141 if (bh == NULL)
1142 return -EIO;
1143 eh = ext_block_hdr(bh);
1144 if (ext4_ext_check_header(inode, eh, depth)) {
1145 put_bh(bh);
1146 return -EIO;
1147 }
1148 ix = EXT_FIRST_INDEX(eh);
1149 block = idx_pblock(ix);
1150 put_bh(bh);
1151 }
1152
1153 bh = sb_bread(inode->i_sb, block);
1154 if (bh == NULL)
1155 return -EIO;
1156 eh = ext_block_hdr(bh);
1157 if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) {
1158 put_bh(bh);
1159 return -EIO;
1160 }
1161 ex = EXT_FIRST_EXTENT(eh);
1162 *logical = le32_to_cpu(ex->ee_block);
1163 *phys = ext_pblock(ex);
1164 put_bh(bh);
1165 return 0;
1166
1167}
1168
1169/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001170 * ext4_ext_next_allocated_block:
1171 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
1172 * NOTE: it considers block number from index entry as
1173 * allocated block. Thus, index entries have to be consistent
1174 * with leaves.
Alex Tomasa86c6182006-10-11 01:21:03 -07001175 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001176static ext4_lblk_t
Alex Tomasa86c6182006-10-11 01:21:03 -07001177ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1178{
1179 int depth;
1180
1181 BUG_ON(path == NULL);
1182 depth = path->p_depth;
1183
1184 if (depth == 0 && path->p_ext == NULL)
1185 return EXT_MAX_BLOCK;
1186
1187 while (depth >= 0) {
1188 if (depth == path->p_depth) {
1189 /* leaf */
1190 if (path[depth].p_ext !=
1191 EXT_LAST_EXTENT(path[depth].p_hdr))
1192 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1193 } else {
1194 /* index */
1195 if (path[depth].p_idx !=
1196 EXT_LAST_INDEX(path[depth].p_hdr))
1197 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1198 }
1199 depth--;
1200 }
1201
1202 return EXT_MAX_BLOCK;
1203}
1204
1205/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001206 * ext4_ext_next_leaf_block:
Alex Tomasa86c6182006-10-11 01:21:03 -07001207 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1208 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001209static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
Andrew Morton63f57932006-10-11 01:21:24 -07001210 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -07001211{
1212 int depth;
1213
1214 BUG_ON(path == NULL);
1215 depth = path->p_depth;
1216
1217 /* zero-tree has no leaf blocks at all */
1218 if (depth == 0)
1219 return EXT_MAX_BLOCK;
1220
1221 /* go to index block */
1222 depth--;
1223
1224 while (depth >= 0) {
1225 if (path[depth].p_idx !=
1226 EXT_LAST_INDEX(path[depth].p_hdr))
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001227 return (ext4_lblk_t)
1228 le32_to_cpu(path[depth].p_idx[1].ei_block);
Alex Tomasa86c6182006-10-11 01:21:03 -07001229 depth--;
1230 }
1231
1232 return EXT_MAX_BLOCK;
1233}
1234
1235/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001236 * ext4_ext_correct_indexes:
1237 * if leaf gets modified and modified extent is first in the leaf,
1238 * then we have to correct all indexes above.
Alex Tomasa86c6182006-10-11 01:21:03 -07001239 * TODO: do we need to correct tree in all cases?
1240 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001241static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001242 struct ext4_ext_path *path)
1243{
1244 struct ext4_extent_header *eh;
1245 int depth = ext_depth(inode);
1246 struct ext4_extent *ex;
1247 __le32 border;
1248 int k, err = 0;
1249
1250 eh = path[depth].p_hdr;
1251 ex = path[depth].p_ext;
1252 BUG_ON(ex == NULL);
1253 BUG_ON(eh == NULL);
1254
1255 if (depth == 0) {
1256 /* there is no tree at all */
1257 return 0;
1258 }
1259
1260 if (ex != EXT_FIRST_EXTENT(eh)) {
1261 /* we correct tree if first leaf got modified only */
1262 return 0;
1263 }
1264
1265 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001266 * TODO: we need correction if border is smaller than current one
Alex Tomasa86c6182006-10-11 01:21:03 -07001267 */
1268 k = depth - 1;
1269 border = path[depth].p_ext->ee_block;
Avantika Mathur7e028972006-12-06 20:41:33 -08001270 err = ext4_ext_get_access(handle, inode, path + k);
1271 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001272 return err;
1273 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001274 err = ext4_ext_dirty(handle, inode, path + k);
1275 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001276 return err;
1277
1278 while (k--) {
1279 /* change all left-side indexes */
1280 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1281 break;
Avantika Mathur7e028972006-12-06 20:41:33 -08001282 err = ext4_ext_get_access(handle, inode, path + k);
1283 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001284 break;
1285 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001286 err = ext4_ext_dirty(handle, inode, path + k);
1287 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001288 break;
1289 }
1290
1291 return err;
1292}
1293
Avantika Mathur09b88252006-12-06 20:41:36 -08001294static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001295ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1296 struct ext4_extent *ex2)
1297{
Amit Arora749269f2007-07-18 09:02:56 -04001298 unsigned short ext1_ee_len, ext2_ee_len, max_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001299
1300 /*
1301 * Make sure that either both extents are uninitialized, or
1302 * both are _not_.
1303 */
1304 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1305 return 0;
1306
Amit Arora749269f2007-07-18 09:02:56 -04001307 if (ext4_ext_is_uninitialized(ex1))
1308 max_len = EXT_UNINIT_MAX_LEN;
1309 else
1310 max_len = EXT_INIT_MAX_LEN;
1311
Amit Aroraa2df2a62007-07-17 21:42:41 -04001312 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1313 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1314
1315 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
Andrew Morton63f57932006-10-11 01:21:24 -07001316 le32_to_cpu(ex2->ee_block))
Alex Tomasa86c6182006-10-11 01:21:03 -07001317 return 0;
1318
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001319 /*
1320 * To allow future support for preallocated extents to be added
1321 * as an RO_COMPAT feature, refuse to merge to extents if
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001322 * this can result in the top bit of ee_len being set.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001323 */
Amit Arora749269f2007-07-18 09:02:56 -04001324 if (ext1_ee_len + ext2_ee_len > max_len)
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001325 return 0;
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01001326#ifdef AGGRESSIVE_TEST
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001327 if (ext1_ee_len >= 4)
Alex Tomasa86c6182006-10-11 01:21:03 -07001328 return 0;
1329#endif
1330
Amit Aroraa2df2a62007-07-17 21:42:41 -04001331 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
Alex Tomasa86c6182006-10-11 01:21:03 -07001332 return 1;
1333 return 0;
1334}
1335
1336/*
Amit Arora56055d32007-07-17 21:42:38 -04001337 * This function tries to merge the "ex" extent to the next extent in the tree.
1338 * It always tries to merge towards right. If you want to merge towards
1339 * left, pass "ex - 1" as argument instead of "ex".
1340 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1341 * 1 if they got merged.
1342 */
1343int ext4_ext_try_to_merge(struct inode *inode,
1344 struct ext4_ext_path *path,
1345 struct ext4_extent *ex)
1346{
1347 struct ext4_extent_header *eh;
1348 unsigned int depth, len;
1349 int merge_done = 0;
1350 int uninitialized = 0;
1351
1352 depth = ext_depth(inode);
1353 BUG_ON(path[depth].p_hdr == NULL);
1354 eh = path[depth].p_hdr;
1355
1356 while (ex < EXT_LAST_EXTENT(eh)) {
1357 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1358 break;
1359 /* merge with next extent! */
1360 if (ext4_ext_is_uninitialized(ex))
1361 uninitialized = 1;
1362 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1363 + ext4_ext_get_actual_len(ex + 1));
1364 if (uninitialized)
1365 ext4_ext_mark_uninitialized(ex);
1366
1367 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1368 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1369 * sizeof(struct ext4_extent);
1370 memmove(ex + 1, ex + 2, len);
1371 }
1372 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries) - 1);
1373 merge_done = 1;
1374 WARN_ON(eh->eh_entries == 0);
1375 if (!eh->eh_entries)
1376 ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
1377 "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
1378 }
1379
1380 return merge_done;
1381}
1382
1383/*
Amit Arora25d14f92007-05-24 13:04:13 -04001384 * check if a portion of the "newext" extent overlaps with an
1385 * existing extent.
1386 *
1387 * If there is an overlap discovered, it updates the length of the newext
1388 * such that there will be no overlap, and then returns 1.
1389 * If there is no overlap found, it returns 0.
1390 */
1391unsigned int ext4_ext_check_overlap(struct inode *inode,
1392 struct ext4_extent *newext,
1393 struct ext4_ext_path *path)
1394{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001395 ext4_lblk_t b1, b2;
Amit Arora25d14f92007-05-24 13:04:13 -04001396 unsigned int depth, len1;
1397 unsigned int ret = 0;
1398
1399 b1 = le32_to_cpu(newext->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001400 len1 = ext4_ext_get_actual_len(newext);
Amit Arora25d14f92007-05-24 13:04:13 -04001401 depth = ext_depth(inode);
1402 if (!path[depth].p_ext)
1403 goto out;
1404 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1405
1406 /*
1407 * get the next allocated block if the extent in the path
1408 * is before the requested block(s)
1409 */
1410 if (b2 < b1) {
1411 b2 = ext4_ext_next_allocated_block(path);
1412 if (b2 == EXT_MAX_BLOCK)
1413 goto out;
1414 }
1415
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001416 /* check for wrap through zero on extent logical start block*/
Amit Arora25d14f92007-05-24 13:04:13 -04001417 if (b1 + len1 < b1) {
1418 len1 = EXT_MAX_BLOCK - b1;
1419 newext->ee_len = cpu_to_le16(len1);
1420 ret = 1;
1421 }
1422
1423 /* check for overlap */
1424 if (b1 + len1 > b2) {
1425 newext->ee_len = cpu_to_le16(b2 - b1);
1426 ret = 1;
1427 }
1428out:
1429 return ret;
1430}
1431
1432/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001433 * ext4_ext_insert_extent:
1434 * tries to merge requsted extent into the existing extent or
1435 * inserts requested extent as new one into the tree,
1436 * creating new leaf in the no-space case.
Alex Tomasa86c6182006-10-11 01:21:03 -07001437 */
1438int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1439 struct ext4_ext_path *path,
1440 struct ext4_extent *newext)
1441{
1442 struct ext4_extent_header * eh;
1443 struct ext4_extent *ex, *fex;
1444 struct ext4_extent *nearex; /* nearest extent */
1445 struct ext4_ext_path *npath = NULL;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001446 int depth, len, err;
1447 ext4_lblk_t next;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001448 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001449
Amit Aroraa2df2a62007-07-17 21:42:41 -04001450 BUG_ON(ext4_ext_get_actual_len(newext) == 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07001451 depth = ext_depth(inode);
1452 ex = path[depth].p_ext;
1453 BUG_ON(path[depth].p_hdr == NULL);
1454
1455 /* try to insert block into found extent and return */
1456 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
Mingming Cao2ae02102006-10-11 01:21:11 -07001457 ext_debug("append %d block to %d:%d (from %llu)\n",
Amit Aroraa2df2a62007-07-17 21:42:41 -04001458 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001459 le32_to_cpu(ex->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001460 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Avantika Mathur7e028972006-12-06 20:41:33 -08001461 err = ext4_ext_get_access(handle, inode, path + depth);
1462 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001463 return err;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001464
1465 /*
1466 * ext4_can_extents_be_merged should have checked that either
1467 * both extents are uninitialized, or both aren't. Thus we
1468 * need to check only one of them here.
1469 */
1470 if (ext4_ext_is_uninitialized(ex))
1471 uninitialized = 1;
1472 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1473 + ext4_ext_get_actual_len(newext));
1474 if (uninitialized)
1475 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001476 eh = path[depth].p_hdr;
1477 nearex = ex;
1478 goto merge;
1479 }
1480
1481repeat:
1482 depth = ext_depth(inode);
1483 eh = path[depth].p_hdr;
1484 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1485 goto has_space;
1486
1487 /* probably next leaf has space for us? */
1488 fex = EXT_LAST_EXTENT(eh);
1489 next = ext4_ext_next_leaf_block(inode, path);
1490 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
1491 && next != EXT_MAX_BLOCK) {
1492 ext_debug("next leaf block - %d\n", next);
1493 BUG_ON(npath != NULL);
1494 npath = ext4_ext_find_extent(inode, next, NULL);
1495 if (IS_ERR(npath))
1496 return PTR_ERR(npath);
1497 BUG_ON(npath->p_depth != path->p_depth);
1498 eh = npath[depth].p_hdr;
1499 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1500 ext_debug("next leaf isnt full(%d)\n",
1501 le16_to_cpu(eh->eh_entries));
1502 path = npath;
1503 goto repeat;
1504 }
1505 ext_debug("next leaf has no free space(%d,%d)\n",
1506 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1507 }
1508
1509 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001510 * There is no free space in the found leaf.
1511 * We're gonna add a new leaf in the tree.
Alex Tomasa86c6182006-10-11 01:21:03 -07001512 */
1513 err = ext4_ext_create_new_leaf(handle, inode, path, newext);
1514 if (err)
1515 goto cleanup;
1516 depth = ext_depth(inode);
1517 eh = path[depth].p_hdr;
1518
1519has_space:
1520 nearex = path[depth].p_ext;
1521
Avantika Mathur7e028972006-12-06 20:41:33 -08001522 err = ext4_ext_get_access(handle, inode, path + depth);
1523 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001524 goto cleanup;
1525
1526 if (!nearex) {
1527 /* there is no extent in this leaf, create first one */
Mingming Cao2ae02102006-10-11 01:21:11 -07001528 ext_debug("first extent in the leaf: %d:%llu:%d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001529 le32_to_cpu(newext->ee_block),
1530 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001531 ext4_ext_get_actual_len(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001532 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1533 } else if (le32_to_cpu(newext->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001534 > le32_to_cpu(nearex->ee_block)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001535/* BUG_ON(newext->ee_block == nearex->ee_block); */
1536 if (nearex != EXT_LAST_EXTENT(eh)) {
1537 len = EXT_MAX_EXTENT(eh) - nearex;
1538 len = (len - 1) * sizeof(struct ext4_extent);
1539 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001540 ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001541 "move %d from 0x%p to 0x%p\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001542 le32_to_cpu(newext->ee_block),
1543 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001544 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001545 nearex, len, nearex + 1, nearex + 2);
1546 memmove(nearex + 2, nearex + 1, len);
1547 }
1548 path[depth].p_ext = nearex + 1;
1549 } else {
1550 BUG_ON(newext->ee_block == nearex->ee_block);
1551 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1552 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001553 ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001554 "move %d from 0x%p to 0x%p\n",
1555 le32_to_cpu(newext->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001556 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001557 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001558 nearex, len, nearex + 1, nearex + 2);
1559 memmove(nearex + 1, nearex, len);
1560 path[depth].p_ext = nearex;
1561 }
1562
1563 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1);
1564 nearex = path[depth].p_ext;
1565 nearex->ee_block = newext->ee_block;
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -04001566 ext4_ext_store_pblock(nearex, ext_pblock(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001567 nearex->ee_len = newext->ee_len;
Alex Tomasa86c6182006-10-11 01:21:03 -07001568
1569merge:
1570 /* try to merge extents to the right */
Amit Arora56055d32007-07-17 21:42:38 -04001571 ext4_ext_try_to_merge(inode, path, nearex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001572
1573 /* try to merge extents to the left */
1574
1575 /* time to correct all indexes above */
1576 err = ext4_ext_correct_indexes(handle, inode, path);
1577 if (err)
1578 goto cleanup;
1579
1580 err = ext4_ext_dirty(handle, inode, path + depth);
1581
1582cleanup:
1583 if (npath) {
1584 ext4_ext_drop_refs(npath);
1585 kfree(npath);
1586 }
1587 ext4_ext_tree_changed(inode);
1588 ext4_ext_invalidate_cache(inode);
1589 return err;
1590}
1591
Avantika Mathur09b88252006-12-06 20:41:36 -08001592static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001593ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
Mingming Caodd545672007-07-31 00:37:46 -07001594 __u32 len, ext4_fsblk_t start, int type)
Alex Tomasa86c6182006-10-11 01:21:03 -07001595{
1596 struct ext4_ext_cache *cex;
1597 BUG_ON(len == 0);
1598 cex = &EXT4_I(inode)->i_cached_extent;
1599 cex->ec_type = type;
1600 cex->ec_block = block;
1601 cex->ec_len = len;
1602 cex->ec_start = start;
1603}
1604
1605/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001606 * ext4_ext_put_gap_in_cache:
1607 * calculate boundaries of the gap that the requested block fits into
Alex Tomasa86c6182006-10-11 01:21:03 -07001608 * and cache this gap
1609 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001610static void
Alex Tomasa86c6182006-10-11 01:21:03 -07001611ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001612 ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -07001613{
1614 int depth = ext_depth(inode);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001615 unsigned long len;
1616 ext4_lblk_t lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001617 struct ext4_extent *ex;
1618
1619 ex = path[depth].p_ext;
1620 if (ex == NULL) {
1621 /* there is no extent yet, so gap is [0;-] */
1622 lblock = 0;
1623 len = EXT_MAX_BLOCK;
1624 ext_debug("cache gap(whole file):");
1625 } else if (block < le32_to_cpu(ex->ee_block)) {
1626 lblock = block;
1627 len = le32_to_cpu(ex->ee_block) - block;
Eric Sandeenbba90742008-01-28 23:58:27 -05001628 ext_debug("cache gap(before): %u [%u:%u]",
1629 block,
1630 le32_to_cpu(ex->ee_block),
1631 ext4_ext_get_actual_len(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07001632 } else if (block >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001633 + ext4_ext_get_actual_len(ex)) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001634 ext4_lblk_t next;
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001635 lblock = le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001636 + ext4_ext_get_actual_len(ex);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001637
1638 next = ext4_ext_next_allocated_block(path);
Eric Sandeenbba90742008-01-28 23:58:27 -05001639 ext_debug("cache gap(after): [%u:%u] %u",
1640 le32_to_cpu(ex->ee_block),
1641 ext4_ext_get_actual_len(ex),
1642 block);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001643 BUG_ON(next == lblock);
1644 len = next - lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001645 } else {
1646 lblock = len = 0;
1647 BUG();
1648 }
1649
Eric Sandeenbba90742008-01-28 23:58:27 -05001650 ext_debug(" -> %u:%lu\n", lblock, len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001651 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
1652}
1653
Avantika Mathur09b88252006-12-06 20:41:36 -08001654static int
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001655ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
Alex Tomasa86c6182006-10-11 01:21:03 -07001656 struct ext4_extent *ex)
1657{
1658 struct ext4_ext_cache *cex;
1659
1660 cex = &EXT4_I(inode)->i_cached_extent;
1661
1662 /* has cache valid data? */
1663 if (cex->ec_type == EXT4_EXT_CACHE_NO)
1664 return EXT4_EXT_CACHE_NO;
1665
1666 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
1667 cex->ec_type != EXT4_EXT_CACHE_EXTENT);
1668 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001669 ex->ee_block = cpu_to_le32(cex->ec_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001670 ext4_ext_store_pblock(ex, cex->ec_start);
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001671 ex->ee_len = cpu_to_le16(cex->ec_len);
Eric Sandeenbba90742008-01-28 23:58:27 -05001672 ext_debug("%u cached by %u:%u:%llu\n",
1673 block,
1674 cex->ec_block, cex->ec_len, cex->ec_start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001675 return cex->ec_type;
1676 }
1677
1678 /* not in cache */
1679 return EXT4_EXT_CACHE_NO;
1680}
1681
1682/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001683 * ext4_ext_rm_idx:
1684 * removes index from the index block.
1685 * It's used in truncate case only, thus all requests are for
1686 * last index in the block only.
Alex Tomasa86c6182006-10-11 01:21:03 -07001687 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001688static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001689 struct ext4_ext_path *path)
1690{
1691 struct buffer_head *bh;
1692 int err;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001693 ext4_fsblk_t leaf;
Alex Tomasa86c6182006-10-11 01:21:03 -07001694
1695 /* free index block */
1696 path--;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001697 leaf = idx_pblock(path->p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -07001698 BUG_ON(path->p_hdr->eh_entries == 0);
Avantika Mathur7e028972006-12-06 20:41:33 -08001699 err = ext4_ext_get_access(handle, inode, path);
1700 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001701 return err;
1702 path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1);
Avantika Mathur7e028972006-12-06 20:41:33 -08001703 err = ext4_ext_dirty(handle, inode, path);
1704 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001705 return err;
Mingming Cao2ae02102006-10-11 01:21:11 -07001706 ext_debug("index is empty, remove it, free block %llu\n", leaf);
Alex Tomasa86c6182006-10-11 01:21:03 -07001707 bh = sb_find_get_block(inode->i_sb, leaf);
1708 ext4_forget(handle, 1, inode, bh, leaf);
Alex Tomasc9de5602008-01-29 00:19:52 -05001709 ext4_free_blocks(handle, inode, leaf, 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001710 return err;
1711}
1712
1713/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001714 * ext4_ext_calc_credits_for_insert:
1715 * This routine returns max. credits that the extent tree can consume.
Alex Tomasa86c6182006-10-11 01:21:03 -07001716 * It should be OK for low-performance paths like ->writepage()
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001717 * To allow many writing processes to fit into a single transaction,
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05001718 * the caller should calculate credits under i_data_sem and
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001719 * pass the actual path.
Alex Tomasa86c6182006-10-11 01:21:03 -07001720 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001721int ext4_ext_calc_credits_for_insert(struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001722 struct ext4_ext_path *path)
1723{
1724 int depth, needed;
1725
1726 if (path) {
1727 /* probably there is space in leaf? */
1728 depth = ext_depth(inode);
1729 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
1730 < le16_to_cpu(path[depth].p_hdr->eh_max))
1731 return 1;
1732 }
1733
1734 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001735 * given 32-bit logical block (4294967296 blocks), max. tree
Alex Tomasa86c6182006-10-11 01:21:03 -07001736 * can be 4 levels in depth -- 4 * 340^4 == 53453440000.
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001737 * Let's also add one more level for imbalance.
Alex Tomasa86c6182006-10-11 01:21:03 -07001738 */
1739 depth = 5;
1740
1741 /* allocation of new data block(s) */
1742 needed = 2;
1743
1744 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001745 * tree can be full, so it would need to grow in depth:
Johann Lombardifeb18922006-12-06 20:40:46 -08001746 * we need one credit to modify old root, credits for
1747 * new root will be added in split accounting
Alex Tomasa86c6182006-10-11 01:21:03 -07001748 */
Johann Lombardifeb18922006-12-06 20:40:46 -08001749 needed += 1;
Alex Tomasa86c6182006-10-11 01:21:03 -07001750
1751 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001752 * Index split can happen, we would need:
Alex Tomasa86c6182006-10-11 01:21:03 -07001753 * allocate intermediate indexes (bitmap + group)
1754 * + change two blocks at each level, but root (already included)
1755 */
Johann Lombardifeb18922006-12-06 20:40:46 -08001756 needed += (depth * 2) + (depth * 2);
Alex Tomasa86c6182006-10-11 01:21:03 -07001757
1758 /* any allocation modifies superblock */
1759 needed += 1;
1760
1761 return needed;
1762}
1763
1764static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
1765 struct ext4_extent *ex,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001766 ext4_lblk_t from, ext4_lblk_t to)
Alex Tomasa86c6182006-10-11 01:21:03 -07001767{
1768 struct buffer_head *bh;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001769 unsigned short ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasc9de5602008-01-29 00:19:52 -05001770 int i, metadata = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001771
Alex Tomasc9de5602008-01-29 00:19:52 -05001772 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
1773 metadata = 1;
Alex Tomasa86c6182006-10-11 01:21:03 -07001774#ifdef EXTENTS_STATS
1775 {
1776 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Alex Tomasa86c6182006-10-11 01:21:03 -07001777 spin_lock(&sbi->s_ext_stats_lock);
1778 sbi->s_ext_blocks += ee_len;
1779 sbi->s_ext_extents++;
1780 if (ee_len < sbi->s_ext_min)
1781 sbi->s_ext_min = ee_len;
1782 if (ee_len > sbi->s_ext_max)
1783 sbi->s_ext_max = ee_len;
1784 if (ext_depth(inode) > sbi->s_depth_max)
1785 sbi->s_depth_max = ext_depth(inode);
1786 spin_unlock(&sbi->s_ext_stats_lock);
1787 }
1788#endif
1789 if (from >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001790 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001791 /* tail removal */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001792 ext4_lblk_t num;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001793 ext4_fsblk_t start;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001794
Amit Aroraa2df2a62007-07-17 21:42:41 -04001795 num = le32_to_cpu(ex->ee_block) + ee_len - from;
1796 start = ext_pblock(ex) + ee_len - num;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001797 ext_debug("free last %u blocks starting %llu\n", num, start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001798 for (i = 0; i < num; i++) {
1799 bh = sb_find_get_block(inode->i_sb, start + i);
1800 ext4_forget(handle, 0, inode, bh, start + i);
1801 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001802 ext4_free_blocks(handle, inode, start, num, metadata);
Alex Tomasa86c6182006-10-11 01:21:03 -07001803 } else if (from == le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001804 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001805 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
Amit Aroraa2df2a62007-07-17 21:42:41 -04001806 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001807 } else {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001808 printk(KERN_INFO "strange request: removal(2) "
1809 "%u-%u from %u:%u\n",
1810 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001811 }
1812 return 0;
1813}
1814
1815static int
1816ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001817 struct ext4_ext_path *path, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07001818{
1819 int err = 0, correct_index = 0;
1820 int depth = ext_depth(inode), credits;
1821 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001822 ext4_lblk_t a, b, block;
1823 unsigned num;
1824 ext4_lblk_t ex_ee_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07001825 unsigned short ex_ee_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001826 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001827 struct ext4_extent *ex;
1828
Alex Tomasc29c0ae2007-07-18 09:19:09 -04001829 /* the header must be checked already in ext4_ext_remove_space() */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001830 ext_debug("truncate since %u in leaf\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001831 if (!path[depth].p_hdr)
1832 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
1833 eh = path[depth].p_hdr;
1834 BUG_ON(eh == NULL);
Alex Tomasa86c6182006-10-11 01:21:03 -07001835
1836 /* find where to start removing */
1837 ex = EXT_LAST_EXTENT(eh);
1838
1839 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001840 if (ext4_ext_is_uninitialized(ex))
1841 uninitialized = 1;
1842 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001843
1844 while (ex >= EXT_FIRST_EXTENT(eh) &&
1845 ex_ee_block + ex_ee_len > start) {
1846 ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len);
1847 path[depth].p_ext = ex;
1848
1849 a = ex_ee_block > start ? ex_ee_block : start;
1850 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
1851 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
1852
1853 ext_debug(" border %u:%u\n", a, b);
1854
1855 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
1856 block = 0;
1857 num = 0;
1858 BUG();
1859 } else if (a != ex_ee_block) {
1860 /* remove tail of the extent */
1861 block = ex_ee_block;
1862 num = a - block;
1863 } else if (b != ex_ee_block + ex_ee_len - 1) {
1864 /* remove head of the extent */
1865 block = a;
1866 num = b - a;
1867 /* there is no "make a hole" API yet */
1868 BUG();
1869 } else {
1870 /* remove whole extent: excellent! */
1871 block = ex_ee_block;
1872 num = 0;
1873 BUG_ON(a != ex_ee_block);
1874 BUG_ON(b != ex_ee_block + ex_ee_len - 1);
1875 }
1876
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001877 /* at present, extent can't cross block group: */
Alex Tomasa86c6182006-10-11 01:21:03 -07001878 /* leaf + bitmap + group desc + sb + inode */
1879 credits = 5;
1880 if (ex == EXT_FIRST_EXTENT(eh)) {
1881 correct_index = 1;
1882 credits += (ext_depth(inode)) + 1;
1883 }
1884#ifdef CONFIG_QUOTA
1885 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
1886#endif
1887
1888 handle = ext4_ext_journal_restart(handle, credits);
1889 if (IS_ERR(handle)) {
1890 err = PTR_ERR(handle);
1891 goto out;
1892 }
1893
1894 err = ext4_ext_get_access(handle, inode, path + depth);
1895 if (err)
1896 goto out;
1897
1898 err = ext4_remove_blocks(handle, inode, ex, a, b);
1899 if (err)
1900 goto out;
1901
1902 if (num == 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001903 /* this extent is removed; mark slot entirely unused */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001904 ext4_ext_store_pblock(ex, 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07001905 eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1);
1906 }
1907
1908 ex->ee_block = cpu_to_le32(block);
1909 ex->ee_len = cpu_to_le16(num);
Amit Arora749269f2007-07-18 09:02:56 -04001910 /*
1911 * Do not mark uninitialized if all the blocks in the
1912 * extent have been removed.
1913 */
1914 if (uninitialized && num)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001915 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001916
1917 err = ext4_ext_dirty(handle, inode, path + depth);
1918 if (err)
1919 goto out;
1920
Mingming Cao2ae02102006-10-11 01:21:11 -07001921 ext_debug("new extent: %u:%u:%llu\n", block, num,
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001922 ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07001923 ex--;
1924 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001925 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001926 }
1927
1928 if (correct_index && eh->eh_entries)
1929 err = ext4_ext_correct_indexes(handle, inode, path);
1930
1931 /* if this leaf is free, then we should
1932 * remove it from index block above */
1933 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
1934 err = ext4_ext_rm_idx(handle, inode, path + depth);
1935
1936out:
1937 return err;
1938}
1939
1940/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001941 * ext4_ext_more_to_rm:
1942 * returns 1 if current index has to be freed (even partial)
Alex Tomasa86c6182006-10-11 01:21:03 -07001943 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001944static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001945ext4_ext_more_to_rm(struct ext4_ext_path *path)
1946{
1947 BUG_ON(path->p_idx == NULL);
1948
1949 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
1950 return 0;
1951
1952 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001953 * if truncate on deeper level happened, it wasn't partial,
Alex Tomasa86c6182006-10-11 01:21:03 -07001954 * so we have to consider current index for truncation
1955 */
1956 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
1957 return 0;
1958 return 1;
1959}
1960
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001961static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07001962{
1963 struct super_block *sb = inode->i_sb;
1964 int depth = ext_depth(inode);
1965 struct ext4_ext_path *path;
1966 handle_t *handle;
1967 int i = 0, err = 0;
1968
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001969 ext_debug("truncate since %u\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001970
1971 /* probably first extent we're gonna free will be last in block */
1972 handle = ext4_journal_start(inode, depth + 1);
1973 if (IS_ERR(handle))
1974 return PTR_ERR(handle);
1975
1976 ext4_ext_invalidate_cache(inode);
1977
1978 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001979 * We start scanning from right side, freeing all the blocks
1980 * after i_size and walking into the tree depth-wise.
Alex Tomasa86c6182006-10-11 01:21:03 -07001981 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -08001982 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL);
Alex Tomasa86c6182006-10-11 01:21:03 -07001983 if (path == NULL) {
1984 ext4_journal_stop(handle);
1985 return -ENOMEM;
1986 }
Alex Tomasa86c6182006-10-11 01:21:03 -07001987 path[0].p_hdr = ext_inode_hdr(inode);
Alex Tomasc29c0ae2007-07-18 09:19:09 -04001988 if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001989 err = -EIO;
1990 goto out;
1991 }
1992 path[0].p_depth = depth;
1993
1994 while (i >= 0 && err == 0) {
1995 if (i == depth) {
1996 /* this is leaf block */
1997 err = ext4_ext_rm_leaf(handle, inode, path, start);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001998 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07001999 brelse(path[i].p_bh);
2000 path[i].p_bh = NULL;
2001 i--;
2002 continue;
2003 }
2004
2005 /* this is index block */
2006 if (!path[i].p_hdr) {
2007 ext_debug("initialize header\n");
2008 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
Alex Tomasa86c6182006-10-11 01:21:03 -07002009 }
2010
Alex Tomasa86c6182006-10-11 01:21:03 -07002011 if (!path[i].p_idx) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002012 /* this level hasn't been touched yet */
Alex Tomasa86c6182006-10-11 01:21:03 -07002013 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2014 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2015 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2016 path[i].p_hdr,
2017 le16_to_cpu(path[i].p_hdr->eh_entries));
2018 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002019 /* we were already here, see at next index */
Alex Tomasa86c6182006-10-11 01:21:03 -07002020 path[i].p_idx--;
2021 }
2022
2023 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2024 i, EXT_FIRST_INDEX(path[i].p_hdr),
2025 path[i].p_idx);
2026 if (ext4_ext_more_to_rm(path + i)) {
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002027 struct buffer_head *bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002028 /* go to the next level */
Mingming Cao2ae02102006-10-11 01:21:11 -07002029 ext_debug("move to level %d (block %llu)\n",
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002030 i + 1, idx_pblock(path[i].p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -07002031 memset(path + i + 1, 0, sizeof(*path));
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002032 bh = sb_bread(sb, idx_pblock(path[i].p_idx));
2033 if (!bh) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002034 /* should we reset i_size? */
2035 err = -EIO;
2036 break;
2037 }
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002038 if (WARN_ON(i + 1 > depth)) {
2039 err = -EIO;
2040 break;
2041 }
2042 if (ext4_ext_check_header(inode, ext_block_hdr(bh),
2043 depth - i - 1)) {
2044 err = -EIO;
2045 break;
2046 }
2047 path[i + 1].p_bh = bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002048
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002049 /* save actual number of indexes since this
2050 * number is changed at the next iteration */
Alex Tomasa86c6182006-10-11 01:21:03 -07002051 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2052 i++;
2053 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002054 /* we finished processing this index, go up */
Alex Tomasa86c6182006-10-11 01:21:03 -07002055 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002056 /* index is empty, remove it;
Alex Tomasa86c6182006-10-11 01:21:03 -07002057 * handle must be already prepared by the
2058 * truncatei_leaf() */
2059 err = ext4_ext_rm_idx(handle, inode, path + i);
2060 }
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002061 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07002062 brelse(path[i].p_bh);
2063 path[i].p_bh = NULL;
2064 i--;
2065 ext_debug("return to level %d\n", i);
2066 }
2067 }
2068
2069 /* TODO: flexible tree reduction should be here */
2070 if (path->p_hdr->eh_entries == 0) {
2071 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002072 * truncate to zero freed all the tree,
2073 * so we need to correct eh_depth
Alex Tomasa86c6182006-10-11 01:21:03 -07002074 */
2075 err = ext4_ext_get_access(handle, inode, path);
2076 if (err == 0) {
2077 ext_inode_hdr(inode)->eh_depth = 0;
2078 ext_inode_hdr(inode)->eh_max =
2079 cpu_to_le16(ext4_ext_space_root(inode));
2080 err = ext4_ext_dirty(handle, inode, path);
2081 }
2082 }
2083out:
2084 ext4_ext_tree_changed(inode);
2085 ext4_ext_drop_refs(path);
2086 kfree(path);
2087 ext4_journal_stop(handle);
2088
2089 return err;
2090}
2091
2092/*
2093 * called at mount time
2094 */
2095void ext4_ext_init(struct super_block *sb)
2096{
2097 /*
2098 * possible initialization would be here
2099 */
2100
2101 if (test_opt(sb, EXTENTS)) {
2102 printk("EXT4-fs: file extents enabled");
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01002103#ifdef AGGRESSIVE_TEST
2104 printk(", aggressive tests");
Alex Tomasa86c6182006-10-11 01:21:03 -07002105#endif
2106#ifdef CHECK_BINSEARCH
2107 printk(", check binsearch");
2108#endif
2109#ifdef EXTENTS_STATS
2110 printk(", stats");
2111#endif
2112 printk("\n");
2113#ifdef EXTENTS_STATS
2114 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2115 EXT4_SB(sb)->s_ext_min = 1 << 30;
2116 EXT4_SB(sb)->s_ext_max = 0;
2117#endif
2118 }
2119}
2120
2121/*
2122 * called at umount time
2123 */
2124void ext4_ext_release(struct super_block *sb)
2125{
2126 if (!test_opt(sb, EXTENTS))
2127 return;
2128
2129#ifdef EXTENTS_STATS
2130 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2131 struct ext4_sb_info *sbi = EXT4_SB(sb);
2132 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2133 sbi->s_ext_blocks, sbi->s_ext_extents,
2134 sbi->s_ext_blocks / sbi->s_ext_extents);
2135 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2136 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2137 }
2138#endif
2139}
2140
Amit Arora56055d32007-07-17 21:42:38 -04002141/*
2142 * This function is called by ext4_ext_get_blocks() if someone tries to write
2143 * to an uninitialized extent. It may result in splitting the uninitialized
2144 * extent into multiple extents (upto three - one initialized and two
2145 * uninitialized).
2146 * There are three possibilities:
2147 * a> There is no split required: Entire extent should be initialized
2148 * b> Splits in two extents: Write is happening at either end of the extent
2149 * c> Splits in three extents: Somone is writing in middle of the extent
2150 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002151static int ext4_ext_convert_to_initialized(handle_t *handle,
2152 struct inode *inode,
2153 struct ext4_ext_path *path,
2154 ext4_lblk_t iblock,
2155 unsigned long max_blocks)
Amit Arora56055d32007-07-17 21:42:38 -04002156{
2157 struct ext4_extent *ex, newex;
2158 struct ext4_extent *ex1 = NULL;
2159 struct ext4_extent *ex2 = NULL;
2160 struct ext4_extent *ex3 = NULL;
2161 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002162 ext4_lblk_t ee_block;
2163 unsigned int allocated, ee_len, depth;
Amit Arora56055d32007-07-17 21:42:38 -04002164 ext4_fsblk_t newblock;
2165 int err = 0;
2166 int ret = 0;
2167
2168 depth = ext_depth(inode);
2169 eh = path[depth].p_hdr;
2170 ex = path[depth].p_ext;
2171 ee_block = le32_to_cpu(ex->ee_block);
2172 ee_len = ext4_ext_get_actual_len(ex);
2173 allocated = ee_len - (iblock - ee_block);
2174 newblock = iblock - ee_block + ext_pblock(ex);
2175 ex2 = ex;
2176
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002177 err = ext4_ext_get_access(handle, inode, path + depth);
2178 if (err)
2179 goto out;
2180
Amit Arora56055d32007-07-17 21:42:38 -04002181 /* ex1: ee_block to iblock - 1 : uninitialized */
2182 if (iblock > ee_block) {
2183 ex1 = ex;
2184 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2185 ext4_ext_mark_uninitialized(ex1);
2186 ex2 = &newex;
2187 }
2188 /*
2189 * for sanity, update the length of the ex2 extent before
2190 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2191 * overlap of blocks.
2192 */
2193 if (!ex1 && allocated > max_blocks)
2194 ex2->ee_len = cpu_to_le16(max_blocks);
2195 /* ex3: to ee_block + ee_len : uninitialised */
2196 if (allocated > max_blocks) {
2197 unsigned int newdepth;
2198 ex3 = &newex;
2199 ex3->ee_block = cpu_to_le32(iblock + max_blocks);
2200 ext4_ext_store_pblock(ex3, newblock + max_blocks);
2201 ex3->ee_len = cpu_to_le16(allocated - max_blocks);
2202 ext4_ext_mark_uninitialized(ex3);
2203 err = ext4_ext_insert_extent(handle, inode, path, ex3);
2204 if (err)
2205 goto out;
2206 /*
2207 * The depth, and hence eh & ex might change
2208 * as part of the insert above.
2209 */
2210 newdepth = ext_depth(inode);
2211 if (newdepth != depth) {
2212 depth = newdepth;
Aneesh Kumar K.Vb35905c2008-02-25 16:54:37 -05002213 ext4_ext_drop_refs(path);
2214 path = ext4_ext_find_extent(inode, iblock, path);
Amit Arora56055d32007-07-17 21:42:38 -04002215 if (IS_ERR(path)) {
2216 err = PTR_ERR(path);
Amit Arora56055d32007-07-17 21:42:38 -04002217 goto out;
2218 }
2219 eh = path[depth].p_hdr;
2220 ex = path[depth].p_ext;
2221 if (ex2 != &newex)
2222 ex2 = ex;
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002223
2224 err = ext4_ext_get_access(handle, inode, path + depth);
2225 if (err)
2226 goto out;
Amit Arora56055d32007-07-17 21:42:38 -04002227 }
2228 allocated = max_blocks;
2229 }
2230 /*
2231 * If there was a change of depth as part of the
2232 * insertion of ex3 above, we need to update the length
2233 * of the ex1 extent again here
2234 */
2235 if (ex1 && ex1 != ex) {
2236 ex1 = ex;
2237 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2238 ext4_ext_mark_uninitialized(ex1);
2239 ex2 = &newex;
2240 }
2241 /* ex2: iblock to iblock + maxblocks-1 : initialised */
2242 ex2->ee_block = cpu_to_le32(iblock);
Amit Arora56055d32007-07-17 21:42:38 -04002243 ext4_ext_store_pblock(ex2, newblock);
2244 ex2->ee_len = cpu_to_le16(allocated);
2245 if (ex2 != ex)
2246 goto insert;
Amit Arora56055d32007-07-17 21:42:38 -04002247 /*
2248 * New (initialized) extent starts from the first block
2249 * in the current extent. i.e., ex2 == ex
2250 * We have to see if it can be merged with the extent
2251 * on the left.
2252 */
2253 if (ex2 > EXT_FIRST_EXTENT(eh)) {
2254 /*
2255 * To merge left, pass "ex2 - 1" to try_to_merge(),
2256 * since it merges towards right _only_.
2257 */
2258 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
2259 if (ret) {
2260 err = ext4_ext_correct_indexes(handle, inode, path);
2261 if (err)
2262 goto out;
2263 depth = ext_depth(inode);
2264 ex2--;
2265 }
2266 }
2267 /*
2268 * Try to Merge towards right. This might be required
2269 * only when the whole extent is being written to.
2270 * i.e. ex2 == ex and ex3 == NULL.
2271 */
2272 if (!ex3) {
2273 ret = ext4_ext_try_to_merge(inode, path, ex2);
2274 if (ret) {
2275 err = ext4_ext_correct_indexes(handle, inode, path);
2276 if (err)
2277 goto out;
2278 }
2279 }
2280 /* Mark modified extent as dirty */
2281 err = ext4_ext_dirty(handle, inode, path + depth);
2282 goto out;
2283insert:
2284 err = ext4_ext_insert_extent(handle, inode, path, &newex);
2285out:
2286 return err ? err : allocated;
2287}
2288
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002289/*
Mingming Caof5ab0d12008-02-25 15:29:55 -05002290 * Block allocation/map/preallocation routine for extents based files
2291 *
2292 *
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002293 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05002294 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
2295 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
Mingming Caof5ab0d12008-02-25 15:29:55 -05002296 *
2297 * return > 0, number of of blocks already mapped/allocated
2298 * if create == 0 and these are pre-allocated blocks
2299 * buffer head is unmapped
2300 * otherwise blocks are mapped
2301 *
2302 * return = 0, if plain look up failed (blocks have not been allocated)
2303 * buffer head is unmapped
2304 *
2305 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002306 */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002307int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002308 ext4_lblk_t iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07002309 unsigned long max_blocks, struct buffer_head *bh_result,
2310 int create, int extend_disksize)
2311{
2312 struct ext4_ext_path *path = NULL;
Amit Arora56055d32007-07-17 21:42:38 -04002313 struct ext4_extent_header *eh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002314 struct ext4_extent newex, *ex;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002315 ext4_fsblk_t goal, newblock;
Amit Arora56055d32007-07-17 21:42:38 -04002316 int err = 0, depth, ret;
Alex Tomasa86c6182006-10-11 01:21:03 -07002317 unsigned long allocated = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05002318 struct ext4_allocation_request ar;
Alex Tomasa86c6182006-10-11 01:21:03 -07002319
2320 __clear_bit(BH_New, &bh_result->b_state);
Eric Sandeenbba90742008-01-28 23:58:27 -05002321 ext_debug("blocks %u/%lu requested for inode %u\n",
2322 iblock, max_blocks, inode->i_ino);
Alex Tomasa86c6182006-10-11 01:21:03 -07002323
2324 /* check in cache */
Avantika Mathur7e028972006-12-06 20:41:33 -08002325 goal = ext4_ext_in_cache(inode, iblock, &newex);
2326 if (goal) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002327 if (goal == EXT4_EXT_CACHE_GAP) {
2328 if (!create) {
Amit Arora56055d32007-07-17 21:42:38 -04002329 /*
2330 * block isn't allocated yet and
2331 * user doesn't want to allocate it
2332 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002333 goto out2;
2334 }
2335 /* we should allocate requested block */
2336 } else if (goal == EXT4_EXT_CACHE_EXTENT) {
2337 /* block is already allocated */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002338 newblock = iblock
2339 - le32_to_cpu(newex.ee_block)
2340 + ext_pblock(&newex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002341 /* number of remaining blocks in the extent */
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002342 allocated = ext4_ext_get_actual_len(&newex) -
Alex Tomasa86c6182006-10-11 01:21:03 -07002343 (iblock - le32_to_cpu(newex.ee_block));
2344 goto out;
2345 } else {
2346 BUG();
2347 }
2348 }
2349
2350 /* find extent for this block */
2351 path = ext4_ext_find_extent(inode, iblock, NULL);
2352 if (IS_ERR(path)) {
2353 err = PTR_ERR(path);
2354 path = NULL;
2355 goto out2;
2356 }
2357
2358 depth = ext_depth(inode);
2359
2360 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002361 * consistent leaf must not be empty;
2362 * this situation is possible, though, _during_ tree modification;
Alex Tomasa86c6182006-10-11 01:21:03 -07002363 * this is why assert can't be put in ext4_ext_find_extent()
2364 */
2365 BUG_ON(path[depth].p_ext == NULL && depth != 0);
Amit Arora56055d32007-07-17 21:42:38 -04002366 eh = path[depth].p_hdr;
Alex Tomasa86c6182006-10-11 01:21:03 -07002367
Avantika Mathur7e028972006-12-06 20:41:33 -08002368 ex = path[depth].p_ext;
2369 if (ex) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002370 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002371 ext4_fsblk_t ee_start = ext_pblock(ex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002372 unsigned short ee_len;
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002373
2374 /*
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002375 * Uninitialized extents are treated as holes, except that
Amit Arora56055d32007-07-17 21:42:38 -04002376 * we split out initialized portions during a write.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002377 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04002378 ee_len = ext4_ext_get_actual_len(ex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002379 /* if found extent covers block, simply return it */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002380 if (iblock >= ee_block && iblock < ee_block + ee_len) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002381 newblock = iblock - ee_block + ee_start;
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002382 /* number of remaining blocks in the extent */
Alex Tomasa86c6182006-10-11 01:21:03 -07002383 allocated = ee_len - (iblock - ee_block);
Eric Sandeenbba90742008-01-28 23:58:27 -05002384 ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07002385 ee_block, ee_len, newblock);
Amit Arora56055d32007-07-17 21:42:38 -04002386
Amit Aroraa2df2a62007-07-17 21:42:41 -04002387 /* Do not put uninitialized extent in the cache */
Amit Arora56055d32007-07-17 21:42:38 -04002388 if (!ext4_ext_is_uninitialized(ex)) {
Amit Aroraa2df2a62007-07-17 21:42:41 -04002389 ext4_ext_put_in_cache(inode, ee_block,
2390 ee_len, ee_start,
2391 EXT4_EXT_CACHE_EXTENT);
Amit Arora56055d32007-07-17 21:42:38 -04002392 goto out;
2393 }
2394 if (create == EXT4_CREATE_UNINITIALIZED_EXT)
2395 goto out;
2396 if (!create)
2397 goto out2;
2398
2399 ret = ext4_ext_convert_to_initialized(handle, inode,
2400 path, iblock,
2401 max_blocks);
Dmitry Monakhovdbf9d7d2008-01-28 23:58:27 -05002402 if (ret <= 0) {
2403 err = ret;
Amit Arora56055d32007-07-17 21:42:38 -04002404 goto out2;
Dmitry Monakhovdbf9d7d2008-01-28 23:58:27 -05002405 } else
Amit Arora56055d32007-07-17 21:42:38 -04002406 allocated = ret;
2407 goto outnew;
Alex Tomasa86c6182006-10-11 01:21:03 -07002408 }
2409 }
2410
2411 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002412 * requested block isn't allocated yet;
Alex Tomasa86c6182006-10-11 01:21:03 -07002413 * we couldn't try to create block if create flag is zero
2414 */
2415 if (!create) {
Amit Arora56055d32007-07-17 21:42:38 -04002416 /*
2417 * put just found gap into cache to speed up
2418 * subsequent requests
2419 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002420 ext4_ext_put_gap_in_cache(inode, path, iblock);
2421 goto out2;
2422 }
2423 /*
Andrew Morton63f57932006-10-11 01:21:24 -07002424 * Okay, we need to do block allocation. Lazily initialize the block
2425 * allocation info here if necessary.
2426 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002427 if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
2428 ext4_init_block_alloc_info(inode);
2429
Alex Tomasc9de5602008-01-29 00:19:52 -05002430 /* find neighbour allocated blocks */
2431 ar.lleft = iblock;
2432 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
2433 if (err)
2434 goto out2;
2435 ar.lright = iblock;
2436 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
2437 if (err)
2438 goto out2;
Amit Arora25d14f92007-05-24 13:04:13 -04002439
Amit Arora749269f2007-07-18 09:02:56 -04002440 /*
2441 * See if request is beyond maximum number of blocks we can have in
2442 * a single extent. For an initialized extent this limit is
2443 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
2444 * EXT_UNINIT_MAX_LEN.
2445 */
2446 if (max_blocks > EXT_INIT_MAX_LEN &&
2447 create != EXT4_CREATE_UNINITIALIZED_EXT)
2448 max_blocks = EXT_INIT_MAX_LEN;
2449 else if (max_blocks > EXT_UNINIT_MAX_LEN &&
2450 create == EXT4_CREATE_UNINITIALIZED_EXT)
2451 max_blocks = EXT_UNINIT_MAX_LEN;
2452
Amit Arora25d14f92007-05-24 13:04:13 -04002453 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
2454 newex.ee_block = cpu_to_le32(iblock);
2455 newex.ee_len = cpu_to_le16(max_blocks);
2456 err = ext4_ext_check_overlap(inode, &newex, path);
2457 if (err)
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002458 allocated = ext4_ext_get_actual_len(&newex);
Amit Arora25d14f92007-05-24 13:04:13 -04002459 else
2460 allocated = max_blocks;
Alex Tomasc9de5602008-01-29 00:19:52 -05002461
2462 /* allocate new block */
2463 ar.inode = inode;
2464 ar.goal = ext4_ext_find_goal(inode, path, iblock);
2465 ar.logical = iblock;
2466 ar.len = allocated;
2467 if (S_ISREG(inode->i_mode))
2468 ar.flags = EXT4_MB_HINT_DATA;
2469 else
2470 /* disable in-core preallocation for non-regular files */
2471 ar.flags = 0;
2472 newblock = ext4_mb_new_blocks(handle, &ar, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -07002473 if (!newblock)
2474 goto out2;
Mingming Cao2ae02102006-10-11 01:21:11 -07002475 ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07002476 goal, newblock, allocated);
2477
2478 /* try to insert new extent into found leaf and return */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002479 ext4_ext_store_pblock(&newex, newblock);
Alex Tomasc9de5602008-01-29 00:19:52 -05002480 newex.ee_len = cpu_to_le16(ar.len);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002481 if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */
2482 ext4_ext_mark_uninitialized(&newex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002483 err = ext4_ext_insert_extent(handle, inode, path, &newex);
Alex Tomas315054f2007-05-24 13:04:25 -04002484 if (err) {
2485 /* free data blocks we just allocated */
Alex Tomasc9de5602008-01-29 00:19:52 -05002486 /* not a good idea to call discard here directly,
2487 * but otherwise we'd need to call it every free() */
2488 ext4_mb_discard_inode_preallocations(inode);
Alex Tomas315054f2007-05-24 13:04:25 -04002489 ext4_free_blocks(handle, inode, ext_pblock(&newex),
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002490 ext4_ext_get_actual_len(&newex), 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07002491 goto out2;
Alex Tomas315054f2007-05-24 13:04:25 -04002492 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002493
2494 if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize)
2495 EXT4_I(inode)->i_disksize = inode->i_size;
2496
2497 /* previous routine could use block we allocated */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002498 newblock = ext_pblock(&newex);
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002499 allocated = ext4_ext_get_actual_len(&newex);
Amit Arora56055d32007-07-17 21:42:38 -04002500outnew:
Alex Tomasa86c6182006-10-11 01:21:03 -07002501 __set_bit(BH_New, &bh_result->b_state);
2502
Amit Aroraa2df2a62007-07-17 21:42:41 -04002503 /* Cache only when it is _not_ an uninitialized extent */
2504 if (create != EXT4_CREATE_UNINITIALIZED_EXT)
2505 ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
2506 EXT4_EXT_CACHE_EXTENT);
Alex Tomasa86c6182006-10-11 01:21:03 -07002507out:
2508 if (allocated > max_blocks)
2509 allocated = max_blocks;
2510 ext4_ext_show_leaf(inode, path);
2511 __set_bit(BH_Mapped, &bh_result->b_state);
2512 bh_result->b_bdev = inode->i_sb->s_bdev;
2513 bh_result->b_blocknr = newblock;
2514out2:
2515 if (path) {
2516 ext4_ext_drop_refs(path);
2517 kfree(path);
2518 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002519 return err ? err : allocated;
2520}
2521
2522void ext4_ext_truncate(struct inode * inode, struct page *page)
2523{
2524 struct address_space *mapping = inode->i_mapping;
2525 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002526 ext4_lblk_t last_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07002527 handle_t *handle;
2528 int err = 0;
2529
2530 /*
2531 * probably first extent we're gonna free will be last in block
2532 */
2533 err = ext4_writepage_trans_blocks(inode) + 3;
2534 handle = ext4_journal_start(inode, err);
2535 if (IS_ERR(handle)) {
2536 if (page) {
2537 clear_highpage(page);
2538 flush_dcache_page(page);
2539 unlock_page(page);
2540 page_cache_release(page);
2541 }
2542 return;
2543 }
2544
2545 if (page)
2546 ext4_block_truncate_page(handle, page, mapping, inode->i_size);
2547
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05002548 down_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07002549 ext4_ext_invalidate_cache(inode);
2550
Alex Tomasc9de5602008-01-29 00:19:52 -05002551 ext4_mb_discard_inode_preallocations(inode);
2552
Alex Tomasa86c6182006-10-11 01:21:03 -07002553 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002554 * TODO: optimization is possible here.
2555 * Probably we need not scan at all,
2556 * because page truncation is enough.
Alex Tomasa86c6182006-10-11 01:21:03 -07002557 */
2558 if (ext4_orphan_add(handle, inode))
2559 goto out_stop;
2560
2561 /* we have to know where to truncate from in crash case */
2562 EXT4_I(inode)->i_disksize = inode->i_size;
2563 ext4_mark_inode_dirty(handle, inode);
2564
2565 last_block = (inode->i_size + sb->s_blocksize - 1)
2566 >> EXT4_BLOCK_SIZE_BITS(sb);
2567 err = ext4_ext_remove_space(inode, last_block);
2568
2569 /* In a multi-transaction truncate, we only make the final
Amit Arora56055d32007-07-17 21:42:38 -04002570 * transaction synchronous.
2571 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002572 if (IS_SYNC(inode))
2573 handle->h_sync = 1;
2574
2575out_stop:
2576 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002577 * If this was a simple ftruncate() and the file will remain alive,
Alex Tomasa86c6182006-10-11 01:21:03 -07002578 * then we need to clear up the orphan record which we created above.
2579 * However, if this was a real unlink then we were called by
2580 * ext4_delete_inode(), and we allow that function to clean up the
2581 * orphan info for us.
2582 */
2583 if (inode->i_nlink)
2584 ext4_orphan_del(handle, inode);
2585
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05002586 up_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07002587 ext4_journal_stop(handle);
2588}
2589
2590/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002591 * ext4_ext_writepage_trans_blocks:
2592 * calculate max number of blocks we could modify
Alex Tomasa86c6182006-10-11 01:21:03 -07002593 * in order to allocate new block for an inode
2594 */
2595int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
2596{
2597 int needed;
2598
2599 needed = ext4_ext_calc_credits_for_insert(inode, NULL);
2600
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002601 /* caller wants to allocate num blocks, but note it includes sb */
Alex Tomasa86c6182006-10-11 01:21:03 -07002602 needed = needed * num - (num - 1);
2603
2604#ifdef CONFIG_QUOTA
2605 needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
2606#endif
2607
2608 return needed;
2609}
Amit Aroraa2df2a62007-07-17 21:42:41 -04002610
2611/*
2612 * preallocate space for a file. This implements ext4's fallocate inode
2613 * operation, which gets called from sys_fallocate system call.
2614 * For block-mapped files, posix_fallocate should fall back to the method
2615 * of writing zeroes to the required new blocks (the same behavior which is
2616 * expected for file systems which do not support fallocate() system call).
2617 */
2618long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
2619{
2620 handle_t *handle;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002621 ext4_lblk_t block;
2622 unsigned long max_blocks;
Amit Aroraa2df2a62007-07-17 21:42:41 -04002623 ext4_fsblk_t nblocks = 0;
2624 int ret = 0;
2625 int ret2 = 0;
2626 int retries = 0;
2627 struct buffer_head map_bh;
2628 unsigned int credits, blkbits = inode->i_blkbits;
2629
2630 /*
2631 * currently supporting (pre)allocate mode for extent-based
2632 * files _only_
2633 */
2634 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
2635 return -EOPNOTSUPP;
2636
2637 /* preallocation to directories is currently not supported */
2638 if (S_ISDIR(inode->i_mode))
2639 return -ENODEV;
2640
2641 block = offset >> blkbits;
2642 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
2643 - block;
2644
2645 /*
2646 * credits to insert 1 extent into extent tree + buffers to be able to
2647 * modify 1 super block, 1 block bitmap and 1 group descriptor.
2648 */
2649 credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05002650 mutex_lock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002651retry:
2652 while (ret >= 0 && ret < max_blocks) {
2653 block = block + ret;
2654 max_blocks = max_blocks - ret;
2655 handle = ext4_journal_start(inode, credits);
2656 if (IS_ERR(handle)) {
2657 ret = PTR_ERR(handle);
2658 break;
2659 }
2660
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05002661 ret = ext4_get_blocks_wrap(handle, inode, block,
Amit Aroraa2df2a62007-07-17 21:42:41 -04002662 max_blocks, &map_bh,
2663 EXT4_CREATE_UNINITIALIZED_EXT, 0);
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05002664 if (ret <= 0) {
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05002665#ifdef EXT4FS_DEBUG
2666 WARN_ON(ret <= 0);
2667 printk(KERN_ERR "%s: ext4_ext_get_blocks "
2668 "returned error inode#%lu, block=%u, "
2669 "max_blocks=%lu", __func__,
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05002670 inode->i_ino, block, max_blocks);
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05002671#endif
Amit Aroraa2df2a62007-07-17 21:42:41 -04002672 ext4_mark_inode_dirty(handle, inode);
2673 ret2 = ext4_journal_stop(handle);
2674 break;
2675 }
2676 if (ret > 0) {
2677 /* check wrap through sign-bit/zero here */
2678 if ((block + ret) < 0 || (block + ret) < block) {
2679 ret = -EIO;
2680 ext4_mark_inode_dirty(handle, inode);
2681 ret2 = ext4_journal_stop(handle);
2682 break;
2683 }
2684 if (buffer_new(&map_bh) && ((block + ret) >
2685 (EXT4_BLOCK_ALIGN(i_size_read(inode), blkbits)
2686 >> blkbits)))
2687 nblocks = nblocks + ret;
2688 }
2689
2690 /* Update ctime if new blocks get allocated */
2691 if (nblocks) {
2692 struct timespec now;
2693
2694 now = current_fs_time(inode->i_sb);
2695 if (!timespec_equal(&inode->i_ctime, &now))
2696 inode->i_ctime = now;
2697 }
2698
2699 ext4_mark_inode_dirty(handle, inode);
2700 ret2 = ext4_journal_stop(handle);
2701 if (ret2)
2702 break;
2703 }
2704
2705 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2706 goto retry;
2707
2708 /*
2709 * Time to update the file size.
2710 * Update only when preallocation was requested beyond the file size.
2711 */
2712 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
2713 (offset + len) > i_size_read(inode)) {
2714 if (ret > 0) {
2715 /*
2716 * if no error, we assume preallocation succeeded
2717 * completely
2718 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04002719 i_size_write(inode, offset + len);
2720 EXT4_I(inode)->i_disksize = i_size_read(inode);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002721 } else if (ret < 0 && nblocks) {
2722 /* Handle partial allocation scenario */
2723 loff_t newsize;
2724
Amit Aroraa2df2a62007-07-17 21:42:41 -04002725 newsize = (nblocks << blkbits) + i_size_read(inode);
2726 i_size_write(inode, EXT4_BLOCK_ALIGN(newsize, blkbits));
2727 EXT4_I(inode)->i_disksize = i_size_read(inode);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002728 }
2729 }
2730
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05002731 mutex_unlock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002732 return ret > 0 ? ret2 : ret;
2733}