blob: ea2ce3c0ae66ec47db52596ed6d5c22cf844ba65 [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>
Mingming Caocd02ff02007-10-16 18:38:25 -040035#include <linux/jbd2.h>
Alex Tomasa86c6182006-10-11 01:21:03 -070036#include <linux/highuid.h>
37#include <linux/pagemap.h>
38#include <linux/quotaops.h>
39#include <linux/string.h>
40#include <linux/slab.h>
Amit Aroraa2df2a62007-07-17 21:42:41 -040041#include <linux/falloc.h>
Alex Tomasa86c6182006-10-11 01:21:03 -070042#include <asm/uaccess.h>
Eric Sandeen6873fa02008-10-07 00:46:36 -040043#include <linux/fiemap.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040044#include "ext4_jbd2.h"
45#include "ext4_extents.h"
Alex Tomasa86c6182006-10-11 01:21:03 -070046
47
Randy Dunlapd0d856e2006-10-11 01:21:07 -070048/*
49 * ext_pblock:
50 * combine low and high parts of physical block number into ext4_fsblk_t
51 */
Avantika Mathur09b88252006-12-06 20:41:36 -080052static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070053{
54 ext4_fsblk_t block;
55
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -040056 block = le32_to_cpu(ex->ee_start_lo);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070057 block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070058 return block;
59}
60
Randy Dunlapd0d856e2006-10-11 01:21:07 -070061/*
62 * idx_pblock:
63 * combine low and high parts of a leaf physical block number into ext4_fsblk_t
64 */
Aneesh Kumar K.Vc14c6fd2008-01-28 23:58:26 -050065ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070066{
67 ext4_fsblk_t block;
68
Aneesh Kumar K.Vd8dd0b42007-10-16 18:38:25 -040069 block = le32_to_cpu(ix->ei_leaf_lo);
Mingming Cao9b8f1f02006-10-11 01:21:13 -070070 block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -070071 return block;
72}
73
Randy Dunlapd0d856e2006-10-11 01:21:07 -070074/*
75 * ext4_ext_store_pblock:
76 * stores a large physical block number into an extent struct,
77 * breaking it into parts
78 */
Aneesh Kumar K.Vc14c6fd2008-01-28 23:58:26 -050079void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070080{
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -040081 ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070082 ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070083}
84
Randy Dunlapd0d856e2006-10-11 01:21:07 -070085/*
86 * ext4_idx_store_pblock:
87 * stores a large physical block number into an index struct,
88 * breaking it into parts
89 */
Avantika Mathur09b88252006-12-06 20:41:36 -080090static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb)
Alex Tomasf65e6fb2006-10-11 01:21:05 -070091{
Aneesh Kumar K.Vd8dd0b42007-10-16 18:38:25 -040092 ix->ei_leaf_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
Mingming Cao9b8f1f02006-10-11 01:21:13 -070093 ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
Alex Tomasf65e6fb2006-10-11 01:21:05 -070094}
95
Shen Feng9102e4f2008-07-11 19:27:31 -040096static int ext4_ext_journal_restart(handle_t *handle, int needed)
Alex Tomasa86c6182006-10-11 01:21:03 -070097{
98 int err;
99
100 if (handle->h_buffer_credits > needed)
Shen Feng9102e4f2008-07-11 19:27:31 -0400101 return 0;
102 err = ext4_journal_extend(handle, needed);
Theodore Ts'o0123c932008-08-01 20:57:54 -0400103 if (err <= 0)
Shen Feng9102e4f2008-07-11 19:27:31 -0400104 return err;
105 return ext4_journal_restart(handle, needed);
Alex Tomasa86c6182006-10-11 01:21:03 -0700106}
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
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400183/*
184 * Allocation for a meta data block
185 */
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700186static ext4_fsblk_t
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400187ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700188 struct ext4_ext_path *path,
189 struct ext4_extent *ex, int *err)
190{
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700191 ext4_fsblk_t goal, newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700192
193 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
Aneesh Kumar K.V7061eba2008-07-11 19:27:31 -0400194 newblock = ext4_new_meta_block(handle, inode, goal, err);
Alex Tomasa86c6182006-10-11 01:21:03 -0700195 return newblock;
196}
197
Avantika Mathur09b88252006-12-06 20:41:36 -0800198static int ext4_ext_space_block(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700199{
200 int size;
201
202 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
203 / sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100204#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700205 if (size > 6)
206 size = 6;
207#endif
208 return size;
209}
210
Avantika Mathur09b88252006-12-06 20:41:36 -0800211static int ext4_ext_space_block_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700212{
213 int size;
214
215 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
216 / sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100217#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700218 if (size > 5)
219 size = 5;
220#endif
221 return size;
222}
223
Avantika Mathur09b88252006-12-06 20:41:36 -0800224static int ext4_ext_space_root(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700225{
226 int size;
227
228 size = sizeof(EXT4_I(inode)->i_data);
229 size -= sizeof(struct ext4_extent_header);
230 size /= sizeof(struct ext4_extent);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100231#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700232 if (size > 3)
233 size = 3;
234#endif
235 return size;
236}
237
Avantika Mathur09b88252006-12-06 20:41:36 -0800238static int ext4_ext_space_root_idx(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -0700239{
240 int size;
241
242 size = sizeof(EXT4_I(inode)->i_data);
243 size -= sizeof(struct ext4_extent_header);
244 size /= sizeof(struct ext4_extent_idx);
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100245#ifdef AGGRESSIVE_TEST
Alex Tomasa86c6182006-10-11 01:21:03 -0700246 if (size > 4)
247 size = 4;
248#endif
249 return size;
250}
251
Mingming Caod2a17632008-07-14 17:52:37 -0400252/*
253 * Calculate the number of metadata blocks needed
254 * to allocate @blocks
255 * Worse case is one block per extent
256 */
257int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
258{
259 int lcap, icap, rcap, leafs, idxs, num;
260 int newextents = blocks;
261
262 rcap = ext4_ext_space_root_idx(inode);
263 lcap = ext4_ext_space_block(inode);
264 icap = ext4_ext_space_block_idx(inode);
265
266 /* number of new leaf blocks needed */
267 num = leafs = (newextents + lcap - 1) / lcap;
268
269 /*
270 * Worse case, we need separate index block(s)
271 * to link all new leaf blocks
272 */
273 idxs = (leafs + icap - 1) / icap;
274 do {
275 num += idxs;
276 idxs = (idxs + icap - 1) / icap;
277 } while (idxs > rcap);
278
279 return num;
280}
281
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400282static int
283ext4_ext_max_entries(struct inode *inode, int depth)
284{
285 int max;
286
287 if (depth == ext_depth(inode)) {
288 if (depth == 0)
289 max = ext4_ext_space_root(inode);
290 else
291 max = ext4_ext_space_root_idx(inode);
292 } else {
293 if (depth == 0)
294 max = ext4_ext_space_block(inode);
295 else
296 max = ext4_ext_space_block_idx(inode);
297 }
298
299 return max;
300}
301
302static int __ext4_ext_check_header(const char *function, struct inode *inode,
303 struct ext4_extent_header *eh,
304 int depth)
305{
306 const char *error_msg;
307 int max = 0;
308
309 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
310 error_msg = "invalid magic";
311 goto corrupted;
312 }
313 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
314 error_msg = "unexpected eh_depth";
315 goto corrupted;
316 }
317 if (unlikely(eh->eh_max == 0)) {
318 error_msg = "invalid eh_max";
319 goto corrupted;
320 }
321 max = ext4_ext_max_entries(inode, depth);
322 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
323 error_msg = "too large eh_max";
324 goto corrupted;
325 }
326 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
327 error_msg = "invalid eh_entries";
328 goto corrupted;
329 }
330 return 0;
331
332corrupted:
333 ext4_error(inode->i_sb, function,
334 "bad header in inode #%lu: %s - magic %x, "
335 "entries %u, max %u(%u), depth %u(%u)",
336 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
337 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
338 max, le16_to_cpu(eh->eh_depth), depth);
339
340 return -EIO;
341}
342
343#define ext4_ext_check_header(inode, eh, depth) \
Harvey Harrison46e665e2008-04-17 10:38:59 -0400344 __ext4_ext_check_header(__func__, inode, eh, depth)
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400345
Alex Tomasa86c6182006-10-11 01:21:03 -0700346#ifdef EXT_DEBUG
347static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
348{
349 int k, l = path->p_depth;
350
351 ext_debug("path:");
352 for (k = 0; k <= l; k++, path++) {
353 if (path->p_idx) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700354 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700355 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700356 } else if (path->p_ext) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700357 ext_debug(" %d:%d:%llu ",
Alex Tomasa86c6182006-10-11 01:21:03 -0700358 le32_to_cpu(path->p_ext->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400359 ext4_ext_get_actual_len(path->p_ext),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700360 ext_pblock(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700361 } else
362 ext_debug(" []");
363 }
364 ext_debug("\n");
365}
366
367static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
368{
369 int depth = ext_depth(inode);
370 struct ext4_extent_header *eh;
371 struct ext4_extent *ex;
372 int i;
373
374 if (!path)
375 return;
376
377 eh = path[depth].p_hdr;
378 ex = EXT_FIRST_EXTENT(eh);
379
380 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700381 ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400382 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -0700383 }
384 ext_debug("\n");
385}
386#else
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400387#define ext4_ext_show_path(inode, path)
388#define ext4_ext_show_leaf(inode, path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700389#endif
390
Aneesh Kumar K.Vb35905c2008-02-25 16:54:37 -0500391void ext4_ext_drop_refs(struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700392{
393 int depth = path->p_depth;
394 int i;
395
396 for (i = 0; i <= depth; i++, path++)
397 if (path->p_bh) {
398 brelse(path->p_bh);
399 path->p_bh = NULL;
400 }
401}
402
403/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700404 * ext4_ext_binsearch_idx:
405 * binary search for the closest index of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400406 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700407 */
408static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500409ext4_ext_binsearch_idx(struct inode *inode,
410 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700411{
412 struct ext4_extent_header *eh = path->p_hdr;
413 struct ext4_extent_idx *r, *l, *m;
414
Alex Tomasa86c6182006-10-11 01:21:03 -0700415
Eric Sandeenbba90742008-01-28 23:58:27 -0500416 ext_debug("binsearch for %u(idx): ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700417
418 l = EXT_FIRST_INDEX(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400419 r = EXT_LAST_INDEX(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700420 while (l <= r) {
421 m = l + (r - l) / 2;
422 if (block < le32_to_cpu(m->ei_block))
423 r = m - 1;
424 else
425 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400426 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
427 m, le32_to_cpu(m->ei_block),
428 r, le32_to_cpu(r->ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700429 }
430
431 path->p_idx = l - 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700432 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400433 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700434
435#ifdef CHECK_BINSEARCH
436 {
437 struct ext4_extent_idx *chix, *ix;
438 int k;
439
440 chix = ix = EXT_FIRST_INDEX(eh);
441 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
442 if (k != 0 &&
443 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
Theodore Ts'o47760042008-09-08 23:00:52 -0400444 printk(KERN_DEBUG "k=%d, ix=0x%p, "
445 "first=0x%p\n", k,
446 ix, EXT_FIRST_INDEX(eh));
447 printk(KERN_DEBUG "%u <= %u\n",
Alex Tomasa86c6182006-10-11 01:21:03 -0700448 le32_to_cpu(ix->ei_block),
449 le32_to_cpu(ix[-1].ei_block));
450 }
451 BUG_ON(k && le32_to_cpu(ix->ei_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400452 <= le32_to_cpu(ix[-1].ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700453 if (block < le32_to_cpu(ix->ei_block))
454 break;
455 chix = ix;
456 }
457 BUG_ON(chix != path->p_idx);
458 }
459#endif
460
461}
462
463/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700464 * ext4_ext_binsearch:
465 * binary search for closest extent of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400466 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700467 */
468static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500469ext4_ext_binsearch(struct inode *inode,
470 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700471{
472 struct ext4_extent_header *eh = path->p_hdr;
473 struct ext4_extent *r, *l, *m;
474
Alex Tomasa86c6182006-10-11 01:21:03 -0700475 if (eh->eh_entries == 0) {
476 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700477 * this leaf is empty:
478 * we get such a leaf in split/add case
Alex Tomasa86c6182006-10-11 01:21:03 -0700479 */
480 return;
481 }
482
Eric Sandeenbba90742008-01-28 23:58:27 -0500483 ext_debug("binsearch for %u: ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700484
485 l = EXT_FIRST_EXTENT(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400486 r = EXT_LAST_EXTENT(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700487
488 while (l <= r) {
489 m = l + (r - l) / 2;
490 if (block < le32_to_cpu(m->ee_block))
491 r = m - 1;
492 else
493 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400494 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
495 m, le32_to_cpu(m->ee_block),
496 r, le32_to_cpu(r->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700497 }
498
499 path->p_ext = l - 1;
Mingming Cao2ae02102006-10-11 01:21:11 -0700500 ext_debug(" -> %d:%llu:%d ",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400501 le32_to_cpu(path->p_ext->ee_block),
502 ext_pblock(path->p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400503 ext4_ext_get_actual_len(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700504
505#ifdef CHECK_BINSEARCH
506 {
507 struct ext4_extent *chex, *ex;
508 int k;
509
510 chex = ex = EXT_FIRST_EXTENT(eh);
511 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
512 BUG_ON(k && le32_to_cpu(ex->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400513 <= le32_to_cpu(ex[-1].ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700514 if (block < le32_to_cpu(ex->ee_block))
515 break;
516 chex = ex;
517 }
518 BUG_ON(chex != path->p_ext);
519 }
520#endif
521
522}
523
524int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
525{
526 struct ext4_extent_header *eh;
527
528 eh = ext_inode_hdr(inode);
529 eh->eh_depth = 0;
530 eh->eh_entries = 0;
531 eh->eh_magic = EXT4_EXT_MAGIC;
532 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode));
533 ext4_mark_inode_dirty(handle, inode);
534 ext4_ext_invalidate_cache(inode);
535 return 0;
536}
537
538struct ext4_ext_path *
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500539ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
540 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700541{
542 struct ext4_extent_header *eh;
543 struct buffer_head *bh;
544 short int depth, i, ppos = 0, alloc = 0;
545
546 eh = ext_inode_hdr(inode);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400547 depth = ext_depth(inode);
548 if (ext4_ext_check_header(inode, eh, depth))
Alex Tomasa86c6182006-10-11 01:21:03 -0700549 return ERR_PTR(-EIO);
550
Alex Tomasa86c6182006-10-11 01:21:03 -0700551
552 /* account possible depth increase */
553 if (!path) {
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800554 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
Alex Tomasa86c6182006-10-11 01:21:03 -0700555 GFP_NOFS);
556 if (!path)
557 return ERR_PTR(-ENOMEM);
558 alloc = 1;
559 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700560 path[0].p_hdr = eh;
Shen Feng1973adc2008-07-11 19:27:31 -0400561 path[0].p_bh = NULL;
Alex Tomasa86c6182006-10-11 01:21:03 -0700562
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400563 i = depth;
Alex Tomasa86c6182006-10-11 01:21:03 -0700564 /* walk through the tree */
565 while (i) {
566 ext_debug("depth %d: num %d, max %d\n",
567 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400568
Alex Tomasa86c6182006-10-11 01:21:03 -0700569 ext4_ext_binsearch_idx(inode, path + ppos, block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700570 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -0700571 path[ppos].p_depth = i;
572 path[ppos].p_ext = NULL;
573
574 bh = sb_bread(inode->i_sb, path[ppos].p_block);
575 if (!bh)
576 goto err;
577
578 eh = ext_block_hdr(bh);
579 ppos++;
580 BUG_ON(ppos > depth);
581 path[ppos].p_bh = bh;
582 path[ppos].p_hdr = eh;
583 i--;
584
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400585 if (ext4_ext_check_header(inode, eh, i))
Alex Tomasa86c6182006-10-11 01:21:03 -0700586 goto err;
587 }
588
589 path[ppos].p_depth = i;
Alex Tomasa86c6182006-10-11 01:21:03 -0700590 path[ppos].p_ext = NULL;
591 path[ppos].p_idx = NULL;
592
Alex Tomasa86c6182006-10-11 01:21:03 -0700593 /* find extent */
594 ext4_ext_binsearch(inode, path + ppos, block);
Shen Feng1973adc2008-07-11 19:27:31 -0400595 /* if not an empty leaf */
596 if (path[ppos].p_ext)
597 path[ppos].p_block = ext_pblock(path[ppos].p_ext);
Alex Tomasa86c6182006-10-11 01:21:03 -0700598
599 ext4_ext_show_path(inode, path);
600
601 return path;
602
603err:
604 ext4_ext_drop_refs(path);
605 if (alloc)
606 kfree(path);
607 return ERR_PTR(-EIO);
608}
609
610/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700611 * ext4_ext_insert_index:
612 * insert new index [@logical;@ptr] into the block at @curp;
613 * check where to insert: before @curp or after @curp
Alex Tomasa86c6182006-10-11 01:21:03 -0700614 */
615static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
616 struct ext4_ext_path *curp,
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700617 int logical, ext4_fsblk_t ptr)
Alex Tomasa86c6182006-10-11 01:21:03 -0700618{
619 struct ext4_extent_idx *ix;
620 int len, err;
621
Avantika Mathur7e028972006-12-06 20:41:33 -0800622 err = ext4_ext_get_access(handle, inode, curp);
623 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700624 return err;
625
626 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
627 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
628 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
629 /* insert after */
630 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
631 len = (len - 1) * sizeof(struct ext4_extent_idx);
632 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400633 ext_debug("insert new index %d after: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700634 "move %d from 0x%p to 0x%p\n",
635 logical, ptr, len,
636 (curp->p_idx + 1), (curp->p_idx + 2));
637 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
638 }
639 ix = curp->p_idx + 1;
640 } else {
641 /* insert before */
642 len = len * sizeof(struct ext4_extent_idx);
643 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400644 ext_debug("insert new index %d before: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700645 "move %d from 0x%p to 0x%p\n",
646 logical, ptr, len,
647 curp->p_idx, (curp->p_idx + 1));
648 memmove(curp->p_idx + 1, curp->p_idx, len);
649 ix = curp->p_idx;
650 }
651
652 ix->ei_block = cpu_to_le32(logical);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700653 ext4_idx_store_pblock(ix, ptr);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400654 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -0700655
656 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400657 > le16_to_cpu(curp->p_hdr->eh_max));
Alex Tomasa86c6182006-10-11 01:21:03 -0700658 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
659
660 err = ext4_ext_dirty(handle, inode, curp);
661 ext4_std_error(inode->i_sb, err);
662
663 return err;
664}
665
666/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700667 * ext4_ext_split:
668 * inserts new subtree into the path, using free index entry
669 * at depth @at:
670 * - allocates all needed blocks (new leaf and all intermediate index blocks)
671 * - makes decision where to split
672 * - moves remaining extents and index entries (right to the split point)
673 * into the newly allocated blocks
674 * - initializes subtree
Alex Tomasa86c6182006-10-11 01:21:03 -0700675 */
676static int ext4_ext_split(handle_t *handle, struct inode *inode,
677 struct ext4_ext_path *path,
678 struct ext4_extent *newext, int at)
679{
680 struct buffer_head *bh = NULL;
681 int depth = ext_depth(inode);
682 struct ext4_extent_header *neh;
683 struct ext4_extent_idx *fidx;
684 struct ext4_extent *ex;
685 int i = at, k, m, a;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700686 ext4_fsblk_t newblock, oldblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700687 __le32 border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700688 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
Alex Tomasa86c6182006-10-11 01:21:03 -0700689 int err = 0;
690
691 /* make decision: where to split? */
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700692 /* FIXME: now decision is simplest: at current extent */
Alex Tomasa86c6182006-10-11 01:21:03 -0700693
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700694 /* if current leaf will be split, then we should use
Alex Tomasa86c6182006-10-11 01:21:03 -0700695 * border from split point */
696 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));
697 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
698 border = path[depth].p_ext[1].ee_block;
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700699 ext_debug("leaf will be split."
Alex Tomasa86c6182006-10-11 01:21:03 -0700700 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400701 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700702 } else {
703 border = newext->ee_block;
704 ext_debug("leaf will be added."
705 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400706 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700707 }
708
709 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700710 * If error occurs, then we break processing
711 * and mark filesystem read-only. index won't
Alex Tomasa86c6182006-10-11 01:21:03 -0700712 * be inserted and tree will be in consistent
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700713 * state. Next mount will repair buffers too.
Alex Tomasa86c6182006-10-11 01:21:03 -0700714 */
715
716 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700717 * Get array to track all allocated blocks.
718 * We need this to handle errors and free blocks
719 * upon them.
Alex Tomasa86c6182006-10-11 01:21:03 -0700720 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800721 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -0700722 if (!ablocks)
723 return -ENOMEM;
Alex Tomasa86c6182006-10-11 01:21:03 -0700724
725 /* allocate all needed blocks */
726 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
727 for (a = 0; a < depth - at; a++) {
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400728 newblock = ext4_ext_new_meta_block(handle, inode, path,
729 newext, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -0700730 if (newblock == 0)
731 goto cleanup;
732 ablocks[a] = newblock;
733 }
734
735 /* initialize new leaf */
736 newblock = ablocks[--a];
737 BUG_ON(newblock == 0);
738 bh = sb_getblk(inode->i_sb, newblock);
739 if (!bh) {
740 err = -EIO;
741 goto cleanup;
742 }
743 lock_buffer(bh);
744
Avantika Mathur7e028972006-12-06 20:41:33 -0800745 err = ext4_journal_get_create_access(handle, bh);
746 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700747 goto cleanup;
748
749 neh = ext_block_hdr(bh);
750 neh->eh_entries = 0;
751 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
752 neh->eh_magic = EXT4_EXT_MAGIC;
753 neh->eh_depth = 0;
754 ex = EXT_FIRST_EXTENT(neh);
755
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700756 /* move remainder of path[depth] to the new leaf */
Alex Tomasa86c6182006-10-11 01:21:03 -0700757 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);
758 /* start copy from next extent */
759 /* TODO: we could do it by single memmove */
760 m = 0;
761 path[depth].p_ext++;
762 while (path[depth].p_ext <=
763 EXT_MAX_EXTENT(path[depth].p_hdr)) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700764 ext_debug("move %d:%llu:%d in new leaf %llu\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400765 le32_to_cpu(path[depth].p_ext->ee_block),
766 ext_pblock(path[depth].p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400767 ext4_ext_get_actual_len(path[depth].p_ext),
Alex Tomasa86c6182006-10-11 01:21:03 -0700768 newblock);
769 /*memmove(ex++, path[depth].p_ext++,
770 sizeof(struct ext4_extent));
771 neh->eh_entries++;*/
772 path[depth].p_ext++;
773 m++;
774 }
775 if (m) {
776 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400777 le16_add_cpu(&neh->eh_entries, m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700778 }
779
780 set_buffer_uptodate(bh);
781 unlock_buffer(bh);
782
Avantika Mathur7e028972006-12-06 20:41:33 -0800783 err = ext4_journal_dirty_metadata(handle, bh);
784 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700785 goto cleanup;
786 brelse(bh);
787 bh = NULL;
788
789 /* correct old leaf */
790 if (m) {
Avantika Mathur7e028972006-12-06 20:41:33 -0800791 err = ext4_ext_get_access(handle, inode, path + depth);
792 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700793 goto cleanup;
Marcin Slusarze8546d02008-04-17 10:38:59 -0400794 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
Avantika Mathur7e028972006-12-06 20:41:33 -0800795 err = ext4_ext_dirty(handle, inode, path + depth);
796 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700797 goto cleanup;
798
799 }
800
801 /* create intermediate indexes */
802 k = depth - at - 1;
803 BUG_ON(k < 0);
804 if (k)
805 ext_debug("create %d intermediate indices\n", k);
806 /* insert new index into current index block */
807 /* current depth stored in i var */
808 i = depth - 1;
809 while (k--) {
810 oldblock = newblock;
811 newblock = ablocks[--a];
Eric Sandeenbba90742008-01-28 23:58:27 -0500812 bh = sb_getblk(inode->i_sb, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700813 if (!bh) {
814 err = -EIO;
815 goto cleanup;
816 }
817 lock_buffer(bh);
818
Avantika Mathur7e028972006-12-06 20:41:33 -0800819 err = ext4_journal_get_create_access(handle, bh);
820 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700821 goto cleanup;
822
823 neh = ext_block_hdr(bh);
824 neh->eh_entries = cpu_to_le16(1);
825 neh->eh_magic = EXT4_EXT_MAGIC;
826 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
827 neh->eh_depth = cpu_to_le16(depth - i);
828 fidx = EXT_FIRST_INDEX(neh);
829 fidx->ei_block = border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700830 ext4_idx_store_pblock(fidx, oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700831
Eric Sandeenbba90742008-01-28 23:58:27 -0500832 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
833 i, newblock, le32_to_cpu(border), oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700834 /* copy indexes */
835 m = 0;
836 path[i].p_idx++;
837
838 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
839 EXT_MAX_INDEX(path[i].p_hdr));
840 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
841 EXT_LAST_INDEX(path[i].p_hdr));
842 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400843 ext_debug("%d: move %d:%llu in new index %llu\n", i,
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400844 le32_to_cpu(path[i].p_idx->ei_block),
845 idx_pblock(path[i].p_idx),
846 newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700847 /*memmove(++fidx, path[i].p_idx++,
848 sizeof(struct ext4_extent_idx));
849 neh->eh_entries++;
850 BUG_ON(neh->eh_entries > neh->eh_max);*/
851 path[i].p_idx++;
852 m++;
853 }
854 if (m) {
855 memmove(++fidx, path[i].p_idx - m,
856 sizeof(struct ext4_extent_idx) * m);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400857 le16_add_cpu(&neh->eh_entries, m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700858 }
859 set_buffer_uptodate(bh);
860 unlock_buffer(bh);
861
Avantika Mathur7e028972006-12-06 20:41:33 -0800862 err = ext4_journal_dirty_metadata(handle, bh);
863 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700864 goto cleanup;
865 brelse(bh);
866 bh = NULL;
867
868 /* correct old index */
869 if (m) {
870 err = ext4_ext_get_access(handle, inode, path + i);
871 if (err)
872 goto cleanup;
Marcin Slusarze8546d02008-04-17 10:38:59 -0400873 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700874 err = ext4_ext_dirty(handle, inode, path + i);
875 if (err)
876 goto cleanup;
877 }
878
879 i--;
880 }
881
882 /* insert new index */
Alex Tomasa86c6182006-10-11 01:21:03 -0700883 err = ext4_ext_insert_index(handle, inode, path + at,
884 le32_to_cpu(border), newblock);
885
886cleanup:
887 if (bh) {
888 if (buffer_locked(bh))
889 unlock_buffer(bh);
890 brelse(bh);
891 }
892
893 if (err) {
894 /* free all allocated blocks in error case */
895 for (i = 0; i < depth; i++) {
896 if (!ablocks[i])
897 continue;
Alex Tomasc9de5602008-01-29 00:19:52 -0500898 ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -0700899 }
900 }
901 kfree(ablocks);
902
903 return err;
904}
905
906/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700907 * ext4_ext_grow_indepth:
908 * implements tree growing procedure:
909 * - allocates new block
910 * - moves top-level data (index block or leaf) into the new block
911 * - initializes new top-level, creating index that points to the
912 * just created block
Alex Tomasa86c6182006-10-11 01:21:03 -0700913 */
914static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
915 struct ext4_ext_path *path,
916 struct ext4_extent *newext)
917{
918 struct ext4_ext_path *curp = path;
919 struct ext4_extent_header *neh;
920 struct ext4_extent_idx *fidx;
921 struct buffer_head *bh;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700922 ext4_fsblk_t newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700923 int err = 0;
924
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400925 newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -0700926 if (newblock == 0)
927 return err;
928
929 bh = sb_getblk(inode->i_sb, newblock);
930 if (!bh) {
931 err = -EIO;
932 ext4_std_error(inode->i_sb, err);
933 return err;
934 }
935 lock_buffer(bh);
936
Avantika Mathur7e028972006-12-06 20:41:33 -0800937 err = ext4_journal_get_create_access(handle, bh);
938 if (err) {
Alex Tomasa86c6182006-10-11 01:21:03 -0700939 unlock_buffer(bh);
940 goto out;
941 }
942
943 /* move top-level index/leaf into new block */
944 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
945
946 /* set size of new block */
947 neh = ext_block_hdr(bh);
948 /* old root could have indexes or leaves
949 * so calculate e_max right way */
950 if (ext_depth(inode))
951 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode));
952 else
953 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode));
954 neh->eh_magic = EXT4_EXT_MAGIC;
955 set_buffer_uptodate(bh);
956 unlock_buffer(bh);
957
Avantika Mathur7e028972006-12-06 20:41:33 -0800958 err = ext4_journal_dirty_metadata(handle, bh);
959 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700960 goto out;
961
962 /* create index in new top-level index: num,max,pointer */
Avantika Mathur7e028972006-12-06 20:41:33 -0800963 err = ext4_ext_get_access(handle, inode, curp);
964 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700965 goto out;
966
967 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
968 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode));
969 curp->p_hdr->eh_entries = cpu_to_le16(1);
970 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400971
972 if (path[0].p_hdr->eh_depth)
973 curp->p_idx->ei_block =
974 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
975 else
976 curp->p_idx->ei_block =
977 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700978 ext4_idx_store_pblock(curp->p_idx, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700979
980 neh = ext_inode_hdr(inode);
981 fidx = EXT_FIRST_INDEX(neh);
Mingming Cao2ae02102006-10-11 01:21:11 -0700982 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -0700983 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700984 le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700985
986 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
987 err = ext4_ext_dirty(handle, inode, curp);
988out:
989 brelse(bh);
990
991 return err;
992}
993
994/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700995 * ext4_ext_create_new_leaf:
996 * finds empty index and adds new leaf.
997 * if no free index is found, then it requests in-depth growing.
Alex Tomasa86c6182006-10-11 01:21:03 -0700998 */
999static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1000 struct ext4_ext_path *path,
1001 struct ext4_extent *newext)
1002{
1003 struct ext4_ext_path *curp;
1004 int depth, i, err = 0;
1005
1006repeat:
1007 i = depth = ext_depth(inode);
1008
1009 /* walk up to the tree and look for free index entry */
1010 curp = path + depth;
1011 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1012 i--;
1013 curp--;
1014 }
1015
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001016 /* we use already allocated block for index block,
1017 * so subsequent data blocks should be contiguous */
Alex Tomasa86c6182006-10-11 01:21:03 -07001018 if (EXT_HAS_FREE_INDEX(curp)) {
1019 /* if we found index with free entry, then use that
1020 * entry: create all needed subtree and add new leaf */
1021 err = ext4_ext_split(handle, inode, path, newext, i);
Shen Feng787e0982008-07-11 19:27:31 -04001022 if (err)
1023 goto out;
Alex Tomasa86c6182006-10-11 01:21:03 -07001024
1025 /* refill path */
1026 ext4_ext_drop_refs(path);
1027 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001028 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1029 path);
Alex Tomasa86c6182006-10-11 01:21:03 -07001030 if (IS_ERR(path))
1031 err = PTR_ERR(path);
1032 } else {
1033 /* tree is full, time to grow in depth */
1034 err = ext4_ext_grow_indepth(handle, inode, path, newext);
1035 if (err)
1036 goto out;
1037
1038 /* refill path */
1039 ext4_ext_drop_refs(path);
1040 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001041 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1042 path);
Alex Tomasa86c6182006-10-11 01:21:03 -07001043 if (IS_ERR(path)) {
1044 err = PTR_ERR(path);
1045 goto out;
1046 }
1047
1048 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001049 * only first (depth 0 -> 1) produces free space;
1050 * in all other cases we have to split the grown tree
Alex Tomasa86c6182006-10-11 01:21:03 -07001051 */
1052 depth = ext_depth(inode);
1053 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001054 /* now we need to split */
Alex Tomasa86c6182006-10-11 01:21:03 -07001055 goto repeat;
1056 }
1057 }
1058
1059out:
1060 return err;
1061}
1062
1063/*
Alex Tomas1988b512008-01-28 23:58:27 -05001064 * search the closest allocated block to the left for *logical
1065 * and returns it at @logical + it's physical address at @phys
1066 * if *logical is the smallest allocated block, the function
1067 * returns 0 at @phys
1068 * return value contains 0 (success) or error code
1069 */
1070int
1071ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
1072 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1073{
1074 struct ext4_extent_idx *ix;
1075 struct ext4_extent *ex;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001076 int depth, ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001077
1078 BUG_ON(path == NULL);
1079 depth = path->p_depth;
1080 *phys = 0;
1081
1082 if (depth == 0 && path->p_ext == NULL)
1083 return 0;
1084
1085 /* usually extent in the path covers blocks smaller
1086 * then *logical, but it can be that extent is the
1087 * first one in the file */
1088
1089 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001090 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001091 if (*logical < le32_to_cpu(ex->ee_block)) {
1092 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1093 while (--depth >= 0) {
1094 ix = path[depth].p_idx;
1095 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1096 }
1097 return 0;
1098 }
1099
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001100 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001101
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001102 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1103 *phys = ext_pblock(ex) + ee_len - 1;
Alex Tomas1988b512008-01-28 23:58:27 -05001104 return 0;
1105}
1106
1107/*
1108 * search the closest allocated block to the right for *logical
1109 * and returns it at @logical + it's physical address at @phys
1110 * if *logical is the smallest allocated block, the function
1111 * returns 0 at @phys
1112 * return value contains 0 (success) or error code
1113 */
1114int
1115ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
1116 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1117{
1118 struct buffer_head *bh = NULL;
1119 struct ext4_extent_header *eh;
1120 struct ext4_extent_idx *ix;
1121 struct ext4_extent *ex;
1122 ext4_fsblk_t block;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001123 int depth, ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001124
1125 BUG_ON(path == NULL);
1126 depth = path->p_depth;
1127 *phys = 0;
1128
1129 if (depth == 0 && path->p_ext == NULL)
1130 return 0;
1131
1132 /* usually extent in the path covers blocks smaller
1133 * then *logical, but it can be that extent is the
1134 * first one in the file */
1135
1136 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001137 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001138 if (*logical < le32_to_cpu(ex->ee_block)) {
1139 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1140 while (--depth >= 0) {
1141 ix = path[depth].p_idx;
1142 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1143 }
1144 *logical = le32_to_cpu(ex->ee_block);
1145 *phys = ext_pblock(ex);
1146 return 0;
1147 }
1148
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001149 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001150
1151 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1152 /* next allocated block in this leaf */
1153 ex++;
1154 *logical = le32_to_cpu(ex->ee_block);
1155 *phys = ext_pblock(ex);
1156 return 0;
1157 }
1158
1159 /* go up and search for index to the right */
1160 while (--depth >= 0) {
1161 ix = path[depth].p_idx;
1162 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1163 break;
1164 }
1165
1166 if (depth < 0) {
1167 /* we've gone up to the root and
1168 * found no index to the right */
1169 return 0;
1170 }
1171
1172 /* we've found index to the right, let's
1173 * follow it and find the closest allocated
1174 * block to the right */
1175 ix++;
1176 block = idx_pblock(ix);
1177 while (++depth < path->p_depth) {
1178 bh = sb_bread(inode->i_sb, block);
1179 if (bh == NULL)
1180 return -EIO;
1181 eh = ext_block_hdr(bh);
1182 if (ext4_ext_check_header(inode, eh, depth)) {
1183 put_bh(bh);
1184 return -EIO;
1185 }
1186 ix = EXT_FIRST_INDEX(eh);
1187 block = idx_pblock(ix);
1188 put_bh(bh);
1189 }
1190
1191 bh = sb_bread(inode->i_sb, block);
1192 if (bh == NULL)
1193 return -EIO;
1194 eh = ext_block_hdr(bh);
1195 if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) {
1196 put_bh(bh);
1197 return -EIO;
1198 }
1199 ex = EXT_FIRST_EXTENT(eh);
1200 *logical = le32_to_cpu(ex->ee_block);
1201 *phys = ext_pblock(ex);
1202 put_bh(bh);
1203 return 0;
1204
1205}
1206
1207/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001208 * ext4_ext_next_allocated_block:
1209 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
1210 * NOTE: it considers block number from index entry as
1211 * allocated block. Thus, index entries have to be consistent
1212 * with leaves.
Alex Tomasa86c6182006-10-11 01:21:03 -07001213 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001214static ext4_lblk_t
Alex Tomasa86c6182006-10-11 01:21:03 -07001215ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1216{
1217 int depth;
1218
1219 BUG_ON(path == NULL);
1220 depth = path->p_depth;
1221
1222 if (depth == 0 && path->p_ext == NULL)
1223 return EXT_MAX_BLOCK;
1224
1225 while (depth >= 0) {
1226 if (depth == path->p_depth) {
1227 /* leaf */
1228 if (path[depth].p_ext !=
1229 EXT_LAST_EXTENT(path[depth].p_hdr))
1230 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1231 } else {
1232 /* index */
1233 if (path[depth].p_idx !=
1234 EXT_LAST_INDEX(path[depth].p_hdr))
1235 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1236 }
1237 depth--;
1238 }
1239
1240 return EXT_MAX_BLOCK;
1241}
1242
1243/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001244 * ext4_ext_next_leaf_block:
Alex Tomasa86c6182006-10-11 01:21:03 -07001245 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1246 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001247static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
Andrew Morton63f57932006-10-11 01:21:24 -07001248 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -07001249{
1250 int depth;
1251
1252 BUG_ON(path == NULL);
1253 depth = path->p_depth;
1254
1255 /* zero-tree has no leaf blocks at all */
1256 if (depth == 0)
1257 return EXT_MAX_BLOCK;
1258
1259 /* go to index block */
1260 depth--;
1261
1262 while (depth >= 0) {
1263 if (path[depth].p_idx !=
1264 EXT_LAST_INDEX(path[depth].p_hdr))
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001265 return (ext4_lblk_t)
1266 le32_to_cpu(path[depth].p_idx[1].ei_block);
Alex Tomasa86c6182006-10-11 01:21:03 -07001267 depth--;
1268 }
1269
1270 return EXT_MAX_BLOCK;
1271}
1272
1273/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001274 * ext4_ext_correct_indexes:
1275 * if leaf gets modified and modified extent is first in the leaf,
1276 * then we have to correct all indexes above.
Alex Tomasa86c6182006-10-11 01:21:03 -07001277 * TODO: do we need to correct tree in all cases?
1278 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001279static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001280 struct ext4_ext_path *path)
1281{
1282 struct ext4_extent_header *eh;
1283 int depth = ext_depth(inode);
1284 struct ext4_extent *ex;
1285 __le32 border;
1286 int k, err = 0;
1287
1288 eh = path[depth].p_hdr;
1289 ex = path[depth].p_ext;
1290 BUG_ON(ex == NULL);
1291 BUG_ON(eh == NULL);
1292
1293 if (depth == 0) {
1294 /* there is no tree at all */
1295 return 0;
1296 }
1297
1298 if (ex != EXT_FIRST_EXTENT(eh)) {
1299 /* we correct tree if first leaf got modified only */
1300 return 0;
1301 }
1302
1303 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001304 * TODO: we need correction if border is smaller than current one
Alex Tomasa86c6182006-10-11 01:21:03 -07001305 */
1306 k = depth - 1;
1307 border = path[depth].p_ext->ee_block;
Avantika Mathur7e028972006-12-06 20:41:33 -08001308 err = ext4_ext_get_access(handle, inode, path + k);
1309 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001310 return err;
1311 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001312 err = ext4_ext_dirty(handle, inode, path + k);
1313 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001314 return err;
1315
1316 while (k--) {
1317 /* change all left-side indexes */
1318 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1319 break;
Avantika Mathur7e028972006-12-06 20:41:33 -08001320 err = ext4_ext_get_access(handle, inode, path + k);
1321 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001322 break;
1323 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001324 err = ext4_ext_dirty(handle, inode, path + k);
1325 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001326 break;
1327 }
1328
1329 return err;
1330}
1331
Avantika Mathur09b88252006-12-06 20:41:36 -08001332static int
Alex Tomasa86c6182006-10-11 01:21:03 -07001333ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1334 struct ext4_extent *ex2)
1335{
Amit Arora749269f2007-07-18 09:02:56 -04001336 unsigned short ext1_ee_len, ext2_ee_len, max_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001337
1338 /*
1339 * Make sure that either both extents are uninitialized, or
1340 * both are _not_.
1341 */
1342 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1343 return 0;
1344
Amit Arora749269f2007-07-18 09:02:56 -04001345 if (ext4_ext_is_uninitialized(ex1))
1346 max_len = EXT_UNINIT_MAX_LEN;
1347 else
1348 max_len = EXT_INIT_MAX_LEN;
1349
Amit Aroraa2df2a62007-07-17 21:42:41 -04001350 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1351 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1352
1353 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
Andrew Morton63f57932006-10-11 01:21:24 -07001354 le32_to_cpu(ex2->ee_block))
Alex Tomasa86c6182006-10-11 01:21:03 -07001355 return 0;
1356
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001357 /*
1358 * To allow future support for preallocated extents to be added
1359 * as an RO_COMPAT feature, refuse to merge to extents if
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001360 * this can result in the top bit of ee_len being set.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001361 */
Amit Arora749269f2007-07-18 09:02:56 -04001362 if (ext1_ee_len + ext2_ee_len > max_len)
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001363 return 0;
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01001364#ifdef AGGRESSIVE_TEST
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001365 if (ext1_ee_len >= 4)
Alex Tomasa86c6182006-10-11 01:21:03 -07001366 return 0;
1367#endif
1368
Amit Aroraa2df2a62007-07-17 21:42:41 -04001369 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
Alex Tomasa86c6182006-10-11 01:21:03 -07001370 return 1;
1371 return 0;
1372}
1373
1374/*
Amit Arora56055d32007-07-17 21:42:38 -04001375 * This function tries to merge the "ex" extent to the next extent in the tree.
1376 * It always tries to merge towards right. If you want to merge towards
1377 * left, pass "ex - 1" as argument instead of "ex".
1378 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1379 * 1 if they got merged.
1380 */
1381int ext4_ext_try_to_merge(struct inode *inode,
1382 struct ext4_ext_path *path,
1383 struct ext4_extent *ex)
1384{
1385 struct ext4_extent_header *eh;
1386 unsigned int depth, len;
1387 int merge_done = 0;
1388 int uninitialized = 0;
1389
1390 depth = ext_depth(inode);
1391 BUG_ON(path[depth].p_hdr == NULL);
1392 eh = path[depth].p_hdr;
1393
1394 while (ex < EXT_LAST_EXTENT(eh)) {
1395 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1396 break;
1397 /* merge with next extent! */
1398 if (ext4_ext_is_uninitialized(ex))
1399 uninitialized = 1;
1400 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1401 + ext4_ext_get_actual_len(ex + 1));
1402 if (uninitialized)
1403 ext4_ext_mark_uninitialized(ex);
1404
1405 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1406 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1407 * sizeof(struct ext4_extent);
1408 memmove(ex + 1, ex + 2, len);
1409 }
Marcin Slusarze8546d02008-04-17 10:38:59 -04001410 le16_add_cpu(&eh->eh_entries, -1);
Amit Arora56055d32007-07-17 21:42:38 -04001411 merge_done = 1;
1412 WARN_ON(eh->eh_entries == 0);
1413 if (!eh->eh_entries)
1414 ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
1415 "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
1416 }
1417
1418 return merge_done;
1419}
1420
1421/*
Amit Arora25d14f92007-05-24 13:04:13 -04001422 * check if a portion of the "newext" extent overlaps with an
1423 * existing extent.
1424 *
1425 * If there is an overlap discovered, it updates the length of the newext
1426 * such that there will be no overlap, and then returns 1.
1427 * If there is no overlap found, it returns 0.
1428 */
1429unsigned int ext4_ext_check_overlap(struct inode *inode,
1430 struct ext4_extent *newext,
1431 struct ext4_ext_path *path)
1432{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001433 ext4_lblk_t b1, b2;
Amit Arora25d14f92007-05-24 13:04:13 -04001434 unsigned int depth, len1;
1435 unsigned int ret = 0;
1436
1437 b1 = le32_to_cpu(newext->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001438 len1 = ext4_ext_get_actual_len(newext);
Amit Arora25d14f92007-05-24 13:04:13 -04001439 depth = ext_depth(inode);
1440 if (!path[depth].p_ext)
1441 goto out;
1442 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1443
1444 /*
1445 * get the next allocated block if the extent in the path
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001446 * is before the requested block(s)
Amit Arora25d14f92007-05-24 13:04:13 -04001447 */
1448 if (b2 < b1) {
1449 b2 = ext4_ext_next_allocated_block(path);
1450 if (b2 == EXT_MAX_BLOCK)
1451 goto out;
1452 }
1453
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001454 /* check for wrap through zero on extent logical start block*/
Amit Arora25d14f92007-05-24 13:04:13 -04001455 if (b1 + len1 < b1) {
1456 len1 = EXT_MAX_BLOCK - b1;
1457 newext->ee_len = cpu_to_le16(len1);
1458 ret = 1;
1459 }
1460
1461 /* check for overlap */
1462 if (b1 + len1 > b2) {
1463 newext->ee_len = cpu_to_le16(b2 - b1);
1464 ret = 1;
1465 }
1466out:
1467 return ret;
1468}
1469
1470/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001471 * ext4_ext_insert_extent:
1472 * tries to merge requsted extent into the existing extent or
1473 * inserts requested extent as new one into the tree,
1474 * creating new leaf in the no-space case.
Alex Tomasa86c6182006-10-11 01:21:03 -07001475 */
1476int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1477 struct ext4_ext_path *path,
1478 struct ext4_extent *newext)
1479{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001480 struct ext4_extent_header *eh;
Alex Tomasa86c6182006-10-11 01:21:03 -07001481 struct ext4_extent *ex, *fex;
1482 struct ext4_extent *nearex; /* nearest extent */
1483 struct ext4_ext_path *npath = NULL;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001484 int depth, len, err;
1485 ext4_lblk_t next;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001486 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001487
Amit Aroraa2df2a62007-07-17 21:42:41 -04001488 BUG_ON(ext4_ext_get_actual_len(newext) == 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07001489 depth = ext_depth(inode);
1490 ex = path[depth].p_ext;
1491 BUG_ON(path[depth].p_hdr == NULL);
1492
1493 /* try to insert block into found extent and return */
1494 if (ex && ext4_can_extents_be_merged(inode, ex, newext)) {
Mingming Cao2ae02102006-10-11 01:21:11 -07001495 ext_debug("append %d block to %d:%d (from %llu)\n",
Amit Aroraa2df2a62007-07-17 21:42:41 -04001496 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001497 le32_to_cpu(ex->ee_block),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001498 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Avantika Mathur7e028972006-12-06 20:41:33 -08001499 err = ext4_ext_get_access(handle, inode, path + depth);
1500 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001501 return err;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001502
1503 /*
1504 * ext4_can_extents_be_merged should have checked that either
1505 * both extents are uninitialized, or both aren't. Thus we
1506 * need to check only one of them here.
1507 */
1508 if (ext4_ext_is_uninitialized(ex))
1509 uninitialized = 1;
1510 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1511 + ext4_ext_get_actual_len(newext));
1512 if (uninitialized)
1513 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001514 eh = path[depth].p_hdr;
1515 nearex = ex;
1516 goto merge;
1517 }
1518
1519repeat:
1520 depth = ext_depth(inode);
1521 eh = path[depth].p_hdr;
1522 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1523 goto has_space;
1524
1525 /* probably next leaf has space for us? */
1526 fex = EXT_LAST_EXTENT(eh);
1527 next = ext4_ext_next_leaf_block(inode, path);
1528 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
1529 && next != EXT_MAX_BLOCK) {
1530 ext_debug("next leaf block - %d\n", next);
1531 BUG_ON(npath != NULL);
1532 npath = ext4_ext_find_extent(inode, next, NULL);
1533 if (IS_ERR(npath))
1534 return PTR_ERR(npath);
1535 BUG_ON(npath->p_depth != path->p_depth);
1536 eh = npath[depth].p_hdr;
1537 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1538 ext_debug("next leaf isnt full(%d)\n",
1539 le16_to_cpu(eh->eh_entries));
1540 path = npath;
1541 goto repeat;
1542 }
1543 ext_debug("next leaf has no free space(%d,%d)\n",
1544 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1545 }
1546
1547 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001548 * There is no free space in the found leaf.
1549 * We're gonna add a new leaf in the tree.
Alex Tomasa86c6182006-10-11 01:21:03 -07001550 */
1551 err = ext4_ext_create_new_leaf(handle, inode, path, newext);
1552 if (err)
1553 goto cleanup;
1554 depth = ext_depth(inode);
1555 eh = path[depth].p_hdr;
1556
1557has_space:
1558 nearex = path[depth].p_ext;
1559
Avantika Mathur7e028972006-12-06 20:41:33 -08001560 err = ext4_ext_get_access(handle, inode, path + depth);
1561 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001562 goto cleanup;
1563
1564 if (!nearex) {
1565 /* there is no extent in this leaf, create first one */
Mingming Cao2ae02102006-10-11 01:21:11 -07001566 ext_debug("first extent in the leaf: %d:%llu:%d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001567 le32_to_cpu(newext->ee_block),
1568 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001569 ext4_ext_get_actual_len(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001570 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1571 } else if (le32_to_cpu(newext->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001572 > le32_to_cpu(nearex->ee_block)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001573/* BUG_ON(newext->ee_block == nearex->ee_block); */
1574 if (nearex != EXT_LAST_EXTENT(eh)) {
1575 len = EXT_MAX_EXTENT(eh) - nearex;
1576 len = (len - 1) * sizeof(struct ext4_extent);
1577 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001578 ext_debug("insert %d:%llu:%d after: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001579 "move %d from 0x%p to 0x%p\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001580 le32_to_cpu(newext->ee_block),
1581 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001582 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001583 nearex, len, nearex + 1, nearex + 2);
1584 memmove(nearex + 2, nearex + 1, len);
1585 }
1586 path[depth].p_ext = nearex + 1;
1587 } else {
1588 BUG_ON(newext->ee_block == nearex->ee_block);
1589 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1590 len = len < 0 ? 0 : len;
Mingming Cao2ae02102006-10-11 01:21:11 -07001591 ext_debug("insert %d:%llu:%d before: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001592 "move %d from 0x%p to 0x%p\n",
1593 le32_to_cpu(newext->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001594 ext_pblock(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001595 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001596 nearex, len, nearex + 1, nearex + 2);
1597 memmove(nearex + 1, nearex, len);
1598 path[depth].p_ext = nearex;
1599 }
1600
Marcin Slusarze8546d02008-04-17 10:38:59 -04001601 le16_add_cpu(&eh->eh_entries, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001602 nearex = path[depth].p_ext;
1603 nearex->ee_block = newext->ee_block;
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -04001604 ext4_ext_store_pblock(nearex, ext_pblock(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001605 nearex->ee_len = newext->ee_len;
Alex Tomasa86c6182006-10-11 01:21:03 -07001606
1607merge:
1608 /* try to merge extents to the right */
Amit Arora56055d32007-07-17 21:42:38 -04001609 ext4_ext_try_to_merge(inode, path, nearex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001610
1611 /* try to merge extents to the left */
1612
1613 /* time to correct all indexes above */
1614 err = ext4_ext_correct_indexes(handle, inode, path);
1615 if (err)
1616 goto cleanup;
1617
1618 err = ext4_ext_dirty(handle, inode, path + depth);
1619
1620cleanup:
1621 if (npath) {
1622 ext4_ext_drop_refs(npath);
1623 kfree(npath);
1624 }
1625 ext4_ext_tree_changed(inode);
1626 ext4_ext_invalidate_cache(inode);
1627 return err;
1628}
1629
Eric Sandeen6873fa02008-10-07 00:46:36 -04001630int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
1631 ext4_lblk_t num, ext_prepare_callback func,
1632 void *cbdata)
1633{
1634 struct ext4_ext_path *path = NULL;
1635 struct ext4_ext_cache cbex;
1636 struct ext4_extent *ex;
1637 ext4_lblk_t next, start = 0, end = 0;
1638 ext4_lblk_t last = block + num;
1639 int depth, exists, err = 0;
1640
1641 BUG_ON(func == NULL);
1642 BUG_ON(inode == NULL);
1643
1644 while (block < last && block != EXT_MAX_BLOCK) {
1645 num = last - block;
1646 /* find extent for this block */
1647 path = ext4_ext_find_extent(inode, block, path);
1648 if (IS_ERR(path)) {
1649 err = PTR_ERR(path);
1650 path = NULL;
1651 break;
1652 }
1653
1654 depth = ext_depth(inode);
1655 BUG_ON(path[depth].p_hdr == NULL);
1656 ex = path[depth].p_ext;
1657 next = ext4_ext_next_allocated_block(path);
1658
1659 exists = 0;
1660 if (!ex) {
1661 /* there is no extent yet, so try to allocate
1662 * all requested space */
1663 start = block;
1664 end = block + num;
1665 } else if (le32_to_cpu(ex->ee_block) > block) {
1666 /* need to allocate space before found extent */
1667 start = block;
1668 end = le32_to_cpu(ex->ee_block);
1669 if (block + num < end)
1670 end = block + num;
1671 } else if (block >= le32_to_cpu(ex->ee_block)
1672 + ext4_ext_get_actual_len(ex)) {
1673 /* need to allocate space after found extent */
1674 start = block;
1675 end = block + num;
1676 if (end >= next)
1677 end = next;
1678 } else if (block >= le32_to_cpu(ex->ee_block)) {
1679 /*
1680 * some part of requested space is covered
1681 * by found extent
1682 */
1683 start = block;
1684 end = le32_to_cpu(ex->ee_block)
1685 + ext4_ext_get_actual_len(ex);
1686 if (block + num < end)
1687 end = block + num;
1688 exists = 1;
1689 } else {
1690 BUG();
1691 }
1692 BUG_ON(end <= start);
1693
1694 if (!exists) {
1695 cbex.ec_block = start;
1696 cbex.ec_len = end - start;
1697 cbex.ec_start = 0;
1698 cbex.ec_type = EXT4_EXT_CACHE_GAP;
1699 } else {
1700 cbex.ec_block = le32_to_cpu(ex->ee_block);
1701 cbex.ec_len = ext4_ext_get_actual_len(ex);
1702 cbex.ec_start = ext_pblock(ex);
1703 cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
1704 }
1705
1706 BUG_ON(cbex.ec_len == 0);
1707 err = func(inode, path, &cbex, ex, cbdata);
1708 ext4_ext_drop_refs(path);
1709
1710 if (err < 0)
1711 break;
1712
1713 if (err == EXT_REPEAT)
1714 continue;
1715 else if (err == EXT_BREAK) {
1716 err = 0;
1717 break;
1718 }
1719
1720 if (ext_depth(inode) != depth) {
1721 /* depth was changed. we have to realloc path */
1722 kfree(path);
1723 path = NULL;
1724 }
1725
1726 block = cbex.ec_block + cbex.ec_len;
1727 }
1728
1729 if (path) {
1730 ext4_ext_drop_refs(path);
1731 kfree(path);
1732 }
1733
1734 return err;
1735}
1736
Avantika Mathur09b88252006-12-06 20:41:36 -08001737static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001738ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
Mingming Caodd545672007-07-31 00:37:46 -07001739 __u32 len, ext4_fsblk_t start, int type)
Alex Tomasa86c6182006-10-11 01:21:03 -07001740{
1741 struct ext4_ext_cache *cex;
1742 BUG_ON(len == 0);
1743 cex = &EXT4_I(inode)->i_cached_extent;
1744 cex->ec_type = type;
1745 cex->ec_block = block;
1746 cex->ec_len = len;
1747 cex->ec_start = start;
1748}
1749
1750/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001751 * ext4_ext_put_gap_in_cache:
1752 * calculate boundaries of the gap that the requested block fits into
Alex Tomasa86c6182006-10-11 01:21:03 -07001753 * and cache this gap
1754 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001755static void
Alex Tomasa86c6182006-10-11 01:21:03 -07001756ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001757 ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -07001758{
1759 int depth = ext_depth(inode);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001760 unsigned long len;
1761 ext4_lblk_t lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001762 struct ext4_extent *ex;
1763
1764 ex = path[depth].p_ext;
1765 if (ex == NULL) {
1766 /* there is no extent yet, so gap is [0;-] */
1767 lblock = 0;
1768 len = EXT_MAX_BLOCK;
1769 ext_debug("cache gap(whole file):");
1770 } else if (block < le32_to_cpu(ex->ee_block)) {
1771 lblock = block;
1772 len = le32_to_cpu(ex->ee_block) - block;
Eric Sandeenbba90742008-01-28 23:58:27 -05001773 ext_debug("cache gap(before): %u [%u:%u]",
1774 block,
1775 le32_to_cpu(ex->ee_block),
1776 ext4_ext_get_actual_len(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07001777 } else if (block >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001778 + ext4_ext_get_actual_len(ex)) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001779 ext4_lblk_t next;
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001780 lblock = le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001781 + ext4_ext_get_actual_len(ex);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001782
1783 next = ext4_ext_next_allocated_block(path);
Eric Sandeenbba90742008-01-28 23:58:27 -05001784 ext_debug("cache gap(after): [%u:%u] %u",
1785 le32_to_cpu(ex->ee_block),
1786 ext4_ext_get_actual_len(ex),
1787 block);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001788 BUG_ON(next == lblock);
1789 len = next - lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001790 } else {
1791 lblock = len = 0;
1792 BUG();
1793 }
1794
Eric Sandeenbba90742008-01-28 23:58:27 -05001795 ext_debug(" -> %u:%lu\n", lblock, len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001796 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
1797}
1798
Avantika Mathur09b88252006-12-06 20:41:36 -08001799static int
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001800ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
Alex Tomasa86c6182006-10-11 01:21:03 -07001801 struct ext4_extent *ex)
1802{
1803 struct ext4_ext_cache *cex;
1804
1805 cex = &EXT4_I(inode)->i_cached_extent;
1806
1807 /* has cache valid data? */
1808 if (cex->ec_type == EXT4_EXT_CACHE_NO)
1809 return EXT4_EXT_CACHE_NO;
1810
1811 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
1812 cex->ec_type != EXT4_EXT_CACHE_EXTENT);
1813 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001814 ex->ee_block = cpu_to_le32(cex->ec_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001815 ext4_ext_store_pblock(ex, cex->ec_start);
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001816 ex->ee_len = cpu_to_le16(cex->ec_len);
Eric Sandeenbba90742008-01-28 23:58:27 -05001817 ext_debug("%u cached by %u:%u:%llu\n",
1818 block,
1819 cex->ec_block, cex->ec_len, cex->ec_start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001820 return cex->ec_type;
1821 }
1822
1823 /* not in cache */
1824 return EXT4_EXT_CACHE_NO;
1825}
1826
1827/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001828 * ext4_ext_rm_idx:
1829 * removes index from the index block.
1830 * It's used in truncate case only, thus all requests are for
1831 * last index in the block only.
Alex Tomasa86c6182006-10-11 01:21:03 -07001832 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001833static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001834 struct ext4_ext_path *path)
1835{
1836 struct buffer_head *bh;
1837 int err;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001838 ext4_fsblk_t leaf;
Alex Tomasa86c6182006-10-11 01:21:03 -07001839
1840 /* free index block */
1841 path--;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001842 leaf = idx_pblock(path->p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -07001843 BUG_ON(path->p_hdr->eh_entries == 0);
Avantika Mathur7e028972006-12-06 20:41:33 -08001844 err = ext4_ext_get_access(handle, inode, path);
1845 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001846 return err;
Marcin Slusarze8546d02008-04-17 10:38:59 -04001847 le16_add_cpu(&path->p_hdr->eh_entries, -1);
Avantika Mathur7e028972006-12-06 20:41:33 -08001848 err = ext4_ext_dirty(handle, inode, path);
1849 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001850 return err;
Mingming Cao2ae02102006-10-11 01:21:11 -07001851 ext_debug("index is empty, remove it, free block %llu\n", leaf);
Alex Tomasa86c6182006-10-11 01:21:03 -07001852 bh = sb_find_get_block(inode->i_sb, leaf);
1853 ext4_forget(handle, 1, inode, bh, leaf);
Alex Tomasc9de5602008-01-29 00:19:52 -05001854 ext4_free_blocks(handle, inode, leaf, 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001855 return err;
1856}
1857
1858/*
Mingming Caoee12b632008-08-19 22:16:05 -04001859 * ext4_ext_calc_credits_for_single_extent:
1860 * This routine returns max. credits that needed to insert an extent
1861 * to the extent tree.
1862 * When pass the actual path, the caller should calculate credits
1863 * under i_data_sem.
Alex Tomasa86c6182006-10-11 01:21:03 -07001864 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04001865int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
Alex Tomasa86c6182006-10-11 01:21:03 -07001866 struct ext4_ext_path *path)
1867{
Alex Tomasa86c6182006-10-11 01:21:03 -07001868 if (path) {
Mingming Caoee12b632008-08-19 22:16:05 -04001869 int depth = ext_depth(inode);
Mingming Caof3bd1f32008-08-19 22:16:03 -04001870 int ret = 0;
Mingming Caoee12b632008-08-19 22:16:05 -04001871
Alex Tomasa86c6182006-10-11 01:21:03 -07001872 /* probably there is space in leaf? */
Alex Tomasa86c6182006-10-11 01:21:03 -07001873 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
Mingming Caoee12b632008-08-19 22:16:05 -04001874 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
1875
1876 /*
1877 * There are some space in the leaf tree, no
1878 * need to account for leaf block credit
1879 *
1880 * bitmaps and block group descriptor blocks
1881 * and other metadat blocks still need to be
1882 * accounted.
1883 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04001884 /* 1 bitmap, 1 block group descriptor */
Mingming Caoee12b632008-08-19 22:16:05 -04001885 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
1886 }
Alex Tomasa86c6182006-10-11 01:21:03 -07001887 }
1888
Mingming Cao525f4ed2008-08-19 22:15:58 -04001889 return ext4_chunk_trans_blocks(inode, nrblocks);
Mingming Caoee12b632008-08-19 22:16:05 -04001890}
Alex Tomasa86c6182006-10-11 01:21:03 -07001891
Mingming Caoee12b632008-08-19 22:16:05 -04001892/*
1893 * How many index/leaf blocks need to change/allocate to modify nrblocks?
1894 *
1895 * if nrblocks are fit in a single extent (chunk flag is 1), then
1896 * in the worse case, each tree level index/leaf need to be changed
1897 * if the tree split due to insert a new extent, then the old tree
1898 * index/leaf need to be updated too
1899 *
1900 * If the nrblocks are discontiguous, they could cause
1901 * the whole tree split more than once, but this is really rare.
1902 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04001903int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
Mingming Caoee12b632008-08-19 22:16:05 -04001904{
1905 int index;
1906 int depth = ext_depth(inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07001907
Mingming Caoee12b632008-08-19 22:16:05 -04001908 if (chunk)
1909 index = depth * 2;
1910 else
1911 index = depth * 3;
Alex Tomasa86c6182006-10-11 01:21:03 -07001912
Mingming Caoee12b632008-08-19 22:16:05 -04001913 return index;
Alex Tomasa86c6182006-10-11 01:21:03 -07001914}
1915
1916static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
1917 struct ext4_extent *ex,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001918 ext4_lblk_t from, ext4_lblk_t to)
Alex Tomasa86c6182006-10-11 01:21:03 -07001919{
1920 struct buffer_head *bh;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001921 unsigned short ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasc9de5602008-01-29 00:19:52 -05001922 int i, metadata = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001923
Alex Tomasc9de5602008-01-29 00:19:52 -05001924 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
1925 metadata = 1;
Alex Tomasa86c6182006-10-11 01:21:03 -07001926#ifdef EXTENTS_STATS
1927 {
1928 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Alex Tomasa86c6182006-10-11 01:21:03 -07001929 spin_lock(&sbi->s_ext_stats_lock);
1930 sbi->s_ext_blocks += ee_len;
1931 sbi->s_ext_extents++;
1932 if (ee_len < sbi->s_ext_min)
1933 sbi->s_ext_min = ee_len;
1934 if (ee_len > sbi->s_ext_max)
1935 sbi->s_ext_max = ee_len;
1936 if (ext_depth(inode) > sbi->s_depth_max)
1937 sbi->s_depth_max = ext_depth(inode);
1938 spin_unlock(&sbi->s_ext_stats_lock);
1939 }
1940#endif
1941 if (from >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001942 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001943 /* tail removal */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001944 ext4_lblk_t num;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001945 ext4_fsblk_t start;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001946
Amit Aroraa2df2a62007-07-17 21:42:41 -04001947 num = le32_to_cpu(ex->ee_block) + ee_len - from;
1948 start = ext_pblock(ex) + ee_len - num;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001949 ext_debug("free last %u blocks starting %llu\n", num, start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001950 for (i = 0; i < num; i++) {
1951 bh = sb_find_get_block(inode->i_sb, start + i);
1952 ext4_forget(handle, 0, inode, bh, start + i);
1953 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001954 ext4_free_blocks(handle, inode, start, num, metadata);
Alex Tomasa86c6182006-10-11 01:21:03 -07001955 } else if (from == le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001956 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001957 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
Amit Aroraa2df2a62007-07-17 21:42:41 -04001958 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001959 } else {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001960 printk(KERN_INFO "strange request: removal(2) "
1961 "%u-%u from %u:%u\n",
1962 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001963 }
1964 return 0;
1965}
1966
1967static int
1968ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001969 struct ext4_ext_path *path, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07001970{
1971 int err = 0, correct_index = 0;
1972 int depth = ext_depth(inode), credits;
1973 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001974 ext4_lblk_t a, b, block;
1975 unsigned num;
1976 ext4_lblk_t ex_ee_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07001977 unsigned short ex_ee_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001978 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001979 struct ext4_extent *ex;
1980
Alex Tomasc29c0ae2007-07-18 09:19:09 -04001981 /* the header must be checked already in ext4_ext_remove_space() */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001982 ext_debug("truncate since %u in leaf\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07001983 if (!path[depth].p_hdr)
1984 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
1985 eh = path[depth].p_hdr;
1986 BUG_ON(eh == NULL);
Alex Tomasa86c6182006-10-11 01:21:03 -07001987
1988 /* find where to start removing */
1989 ex = EXT_LAST_EXTENT(eh);
1990
1991 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001992 if (ext4_ext_is_uninitialized(ex))
1993 uninitialized = 1;
1994 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001995
1996 while (ex >= EXT_FIRST_EXTENT(eh) &&
1997 ex_ee_block + ex_ee_len > start) {
1998 ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len);
1999 path[depth].p_ext = ex;
2000
2001 a = ex_ee_block > start ? ex_ee_block : start;
2002 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
2003 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
2004
2005 ext_debug(" border %u:%u\n", a, b);
2006
2007 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
2008 block = 0;
2009 num = 0;
2010 BUG();
2011 } else if (a != ex_ee_block) {
2012 /* remove tail of the extent */
2013 block = ex_ee_block;
2014 num = a - block;
2015 } else if (b != ex_ee_block + ex_ee_len - 1) {
2016 /* remove head of the extent */
2017 block = a;
2018 num = b - a;
2019 /* there is no "make a hole" API yet */
2020 BUG();
2021 } else {
2022 /* remove whole extent: excellent! */
2023 block = ex_ee_block;
2024 num = 0;
2025 BUG_ON(a != ex_ee_block);
2026 BUG_ON(b != ex_ee_block + ex_ee_len - 1);
2027 }
2028
Theodore Ts'o34071da2008-08-01 21:59:19 -04002029 /*
2030 * 3 for leaf, sb, and inode plus 2 (bmap and group
2031 * descriptor) for each block group; assume two block
2032 * groups plus ex_ee_len/blocks_per_block_group for
2033 * the worst case
2034 */
2035 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
Alex Tomasa86c6182006-10-11 01:21:03 -07002036 if (ex == EXT_FIRST_EXTENT(eh)) {
2037 correct_index = 1;
2038 credits += (ext_depth(inode)) + 1;
2039 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002040 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
Alex Tomasa86c6182006-10-11 01:21:03 -07002041
Shen Feng9102e4f2008-07-11 19:27:31 -04002042 err = ext4_ext_journal_restart(handle, credits);
2043 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07002044 goto out;
Alex Tomasa86c6182006-10-11 01:21:03 -07002045
2046 err = ext4_ext_get_access(handle, inode, path + depth);
2047 if (err)
2048 goto out;
2049
2050 err = ext4_remove_blocks(handle, inode, ex, a, b);
2051 if (err)
2052 goto out;
2053
2054 if (num == 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002055 /* this extent is removed; mark slot entirely unused */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002056 ext4_ext_store_pblock(ex, 0);
Marcin Slusarze8546d02008-04-17 10:38:59 -04002057 le16_add_cpu(&eh->eh_entries, -1);
Alex Tomasa86c6182006-10-11 01:21:03 -07002058 }
2059
2060 ex->ee_block = cpu_to_le32(block);
2061 ex->ee_len = cpu_to_le16(num);
Amit Arora749269f2007-07-18 09:02:56 -04002062 /*
2063 * Do not mark uninitialized if all the blocks in the
2064 * extent have been removed.
2065 */
2066 if (uninitialized && num)
Amit Aroraa2df2a62007-07-17 21:42:41 -04002067 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002068
2069 err = ext4_ext_dirty(handle, inode, path + depth);
2070 if (err)
2071 goto out;
2072
Mingming Cao2ae02102006-10-11 01:21:11 -07002073 ext_debug("new extent: %u:%u:%llu\n", block, num,
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002074 ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07002075 ex--;
2076 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002077 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002078 }
2079
2080 if (correct_index && eh->eh_entries)
2081 err = ext4_ext_correct_indexes(handle, inode, path);
2082
2083 /* if this leaf is free, then we should
2084 * remove it from index block above */
2085 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2086 err = ext4_ext_rm_idx(handle, inode, path + depth);
2087
2088out:
2089 return err;
2090}
2091
2092/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002093 * ext4_ext_more_to_rm:
2094 * returns 1 if current index has to be freed (even partial)
Alex Tomasa86c6182006-10-11 01:21:03 -07002095 */
Avantika Mathur09b88252006-12-06 20:41:36 -08002096static int
Alex Tomasa86c6182006-10-11 01:21:03 -07002097ext4_ext_more_to_rm(struct ext4_ext_path *path)
2098{
2099 BUG_ON(path->p_idx == NULL);
2100
2101 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2102 return 0;
2103
2104 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002105 * if truncate on deeper level happened, it wasn't partial,
Alex Tomasa86c6182006-10-11 01:21:03 -07002106 * so we have to consider current index for truncation
2107 */
2108 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2109 return 0;
2110 return 1;
2111}
2112
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05002113static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07002114{
2115 struct super_block *sb = inode->i_sb;
2116 int depth = ext_depth(inode);
2117 struct ext4_ext_path *path;
2118 handle_t *handle;
2119 int i = 0, err = 0;
2120
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002121 ext_debug("truncate since %u\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07002122
2123 /* probably first extent we're gonna free will be last in block */
2124 handle = ext4_journal_start(inode, depth + 1);
2125 if (IS_ERR(handle))
2126 return PTR_ERR(handle);
2127
2128 ext4_ext_invalidate_cache(inode);
2129
2130 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002131 * We start scanning from right side, freeing all the blocks
2132 * after i_size and walking into the tree depth-wise.
Alex Tomasa86c6182006-10-11 01:21:03 -07002133 */
Josef Bacik216553c2008-04-29 22:02:02 -04002134 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -07002135 if (path == NULL) {
2136 ext4_journal_stop(handle);
2137 return -ENOMEM;
2138 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002139 path[0].p_hdr = ext_inode_hdr(inode);
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002140 if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002141 err = -EIO;
2142 goto out;
2143 }
2144 path[0].p_depth = depth;
2145
2146 while (i >= 0 && err == 0) {
2147 if (i == depth) {
2148 /* this is leaf block */
2149 err = ext4_ext_rm_leaf(handle, inode, path, start);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002150 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07002151 brelse(path[i].p_bh);
2152 path[i].p_bh = NULL;
2153 i--;
2154 continue;
2155 }
2156
2157 /* this is index block */
2158 if (!path[i].p_hdr) {
2159 ext_debug("initialize header\n");
2160 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
Alex Tomasa86c6182006-10-11 01:21:03 -07002161 }
2162
Alex Tomasa86c6182006-10-11 01:21:03 -07002163 if (!path[i].p_idx) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002164 /* this level hasn't been touched yet */
Alex Tomasa86c6182006-10-11 01:21:03 -07002165 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2166 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2167 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2168 path[i].p_hdr,
2169 le16_to_cpu(path[i].p_hdr->eh_entries));
2170 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002171 /* we were already here, see at next index */
Alex Tomasa86c6182006-10-11 01:21:03 -07002172 path[i].p_idx--;
2173 }
2174
2175 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2176 i, EXT_FIRST_INDEX(path[i].p_hdr),
2177 path[i].p_idx);
2178 if (ext4_ext_more_to_rm(path + i)) {
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002179 struct buffer_head *bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002180 /* go to the next level */
Mingming Cao2ae02102006-10-11 01:21:11 -07002181 ext_debug("move to level %d (block %llu)\n",
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002182 i + 1, idx_pblock(path[i].p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -07002183 memset(path + i + 1, 0, sizeof(*path));
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002184 bh = sb_bread(sb, idx_pblock(path[i].p_idx));
2185 if (!bh) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002186 /* should we reset i_size? */
2187 err = -EIO;
2188 break;
2189 }
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002190 if (WARN_ON(i + 1 > depth)) {
2191 err = -EIO;
2192 break;
2193 }
2194 if (ext4_ext_check_header(inode, ext_block_hdr(bh),
2195 depth - i - 1)) {
2196 err = -EIO;
2197 break;
2198 }
2199 path[i + 1].p_bh = bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002200
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002201 /* save actual number of indexes since this
2202 * number is changed at the next iteration */
Alex Tomasa86c6182006-10-11 01:21:03 -07002203 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2204 i++;
2205 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002206 /* we finished processing this index, go up */
Alex Tomasa86c6182006-10-11 01:21:03 -07002207 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002208 /* index is empty, remove it;
Alex Tomasa86c6182006-10-11 01:21:03 -07002209 * handle must be already prepared by the
2210 * truncatei_leaf() */
2211 err = ext4_ext_rm_idx(handle, inode, path + i);
2212 }
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002213 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07002214 brelse(path[i].p_bh);
2215 path[i].p_bh = NULL;
2216 i--;
2217 ext_debug("return to level %d\n", i);
2218 }
2219 }
2220
2221 /* TODO: flexible tree reduction should be here */
2222 if (path->p_hdr->eh_entries == 0) {
2223 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002224 * truncate to zero freed all the tree,
2225 * so we need to correct eh_depth
Alex Tomasa86c6182006-10-11 01:21:03 -07002226 */
2227 err = ext4_ext_get_access(handle, inode, path);
2228 if (err == 0) {
2229 ext_inode_hdr(inode)->eh_depth = 0;
2230 ext_inode_hdr(inode)->eh_max =
2231 cpu_to_le16(ext4_ext_space_root(inode));
2232 err = ext4_ext_dirty(handle, inode, path);
2233 }
2234 }
2235out:
2236 ext4_ext_tree_changed(inode);
2237 ext4_ext_drop_refs(path);
2238 kfree(path);
2239 ext4_journal_stop(handle);
2240
2241 return err;
2242}
2243
2244/*
2245 * called at mount time
2246 */
2247void ext4_ext_init(struct super_block *sb)
2248{
2249 /*
2250 * possible initialization would be here
2251 */
2252
2253 if (test_opt(sb, EXTENTS)) {
Theodore Ts'o47760042008-09-08 23:00:52 -04002254 printk(KERN_INFO "EXT4-fs: file extents enabled");
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01002255#ifdef AGGRESSIVE_TEST
2256 printk(", aggressive tests");
Alex Tomasa86c6182006-10-11 01:21:03 -07002257#endif
2258#ifdef CHECK_BINSEARCH
2259 printk(", check binsearch");
2260#endif
2261#ifdef EXTENTS_STATS
2262 printk(", stats");
2263#endif
2264 printk("\n");
2265#ifdef EXTENTS_STATS
2266 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2267 EXT4_SB(sb)->s_ext_min = 1 << 30;
2268 EXT4_SB(sb)->s_ext_max = 0;
2269#endif
2270 }
2271}
2272
2273/*
2274 * called at umount time
2275 */
2276void ext4_ext_release(struct super_block *sb)
2277{
2278 if (!test_opt(sb, EXTENTS))
2279 return;
2280
2281#ifdef EXTENTS_STATS
2282 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2283 struct ext4_sb_info *sbi = EXT4_SB(sb);
2284 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2285 sbi->s_ext_blocks, sbi->s_ext_extents,
2286 sbi->s_ext_blocks / sbi->s_ext_extents);
2287 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2288 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2289 }
2290#endif
2291}
2292
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002293static void bi_complete(struct bio *bio, int error)
2294{
2295 complete((struct completion *)bio->bi_private);
2296}
2297
2298/* FIXME!! we need to try to merge to left or right after zero-out */
2299static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2300{
2301 int ret = -EIO;
2302 struct bio *bio;
2303 int blkbits, blocksize;
2304 sector_t ee_pblock;
2305 struct completion event;
2306 unsigned int ee_len, len, done, offset;
2307
2308
2309 blkbits = inode->i_blkbits;
2310 blocksize = inode->i_sb->s_blocksize;
2311 ee_len = ext4_ext_get_actual_len(ex);
2312 ee_pblock = ext_pblock(ex);
2313
2314 /* convert ee_pblock to 512 byte sectors */
2315 ee_pblock = ee_pblock << (blkbits - 9);
2316
2317 while (ee_len > 0) {
2318
2319 if (ee_len > BIO_MAX_PAGES)
2320 len = BIO_MAX_PAGES;
2321 else
2322 len = ee_len;
2323
2324 bio = bio_alloc(GFP_NOIO, len);
2325 if (!bio)
2326 return -ENOMEM;
2327 bio->bi_sector = ee_pblock;
2328 bio->bi_bdev = inode->i_sb->s_bdev;
2329
2330 done = 0;
2331 offset = 0;
2332 while (done < len) {
2333 ret = bio_add_page(bio, ZERO_PAGE(0),
2334 blocksize, offset);
2335 if (ret != blocksize) {
2336 /*
2337 * We can't add any more pages because of
2338 * hardware limitations. Start a new bio.
2339 */
2340 break;
2341 }
2342 done++;
2343 offset += blocksize;
2344 if (offset >= PAGE_CACHE_SIZE)
2345 offset = 0;
2346 }
2347
2348 init_completion(&event);
2349 bio->bi_private = &event;
2350 bio->bi_end_io = bi_complete;
2351 submit_bio(WRITE, bio);
2352 wait_for_completion(&event);
2353
2354 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
2355 ret = 0;
2356 else {
2357 ret = -EIO;
2358 break;
2359 }
2360 bio_put(bio);
2361 ee_len -= done;
2362 ee_pblock += done << (blkbits - 9);
2363 }
2364 return ret;
2365}
2366
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002367#define EXT4_EXT_ZERO_LEN 7
2368
Amit Arora56055d32007-07-17 21:42:38 -04002369/*
2370 * This function is called by ext4_ext_get_blocks() if someone tries to write
2371 * to an uninitialized extent. It may result in splitting the uninitialized
2372 * extent into multiple extents (upto three - one initialized and two
2373 * uninitialized).
2374 * There are three possibilities:
2375 * a> There is no split required: Entire extent should be initialized
2376 * b> Splits in two extents: Write is happening at either end of the extent
2377 * c> Splits in three extents: Somone is writing in middle of the extent
2378 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002379static int ext4_ext_convert_to_initialized(handle_t *handle,
2380 struct inode *inode,
2381 struct ext4_ext_path *path,
2382 ext4_lblk_t iblock,
2383 unsigned long max_blocks)
Amit Arora56055d32007-07-17 21:42:38 -04002384{
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002385 struct ext4_extent *ex, newex, orig_ex;
Amit Arora56055d32007-07-17 21:42:38 -04002386 struct ext4_extent *ex1 = NULL;
2387 struct ext4_extent *ex2 = NULL;
2388 struct ext4_extent *ex3 = NULL;
2389 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002390 ext4_lblk_t ee_block;
2391 unsigned int allocated, ee_len, depth;
Amit Arora56055d32007-07-17 21:42:38 -04002392 ext4_fsblk_t newblock;
2393 int err = 0;
2394 int ret = 0;
2395
2396 depth = ext_depth(inode);
2397 eh = path[depth].p_hdr;
2398 ex = path[depth].p_ext;
2399 ee_block = le32_to_cpu(ex->ee_block);
2400 ee_len = ext4_ext_get_actual_len(ex);
2401 allocated = ee_len - (iblock - ee_block);
2402 newblock = iblock - ee_block + ext_pblock(ex);
2403 ex2 = ex;
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002404 orig_ex.ee_block = ex->ee_block;
2405 orig_ex.ee_len = cpu_to_le16(ee_len);
2406 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
Amit Arora56055d32007-07-17 21:42:38 -04002407
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002408 err = ext4_ext_get_access(handle, inode, path + depth);
2409 if (err)
2410 goto out;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002411 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
2412 if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
2413 err = ext4_ext_zeroout(inode, &orig_ex);
2414 if (err)
2415 goto fix_extent_len;
2416 /* update the extent length and mark as initialized */
2417 ex->ee_block = orig_ex.ee_block;
2418 ex->ee_len = orig_ex.ee_len;
2419 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2420 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002421 /* zeroed the full extent */
2422 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002423 }
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002424
Amit Arora56055d32007-07-17 21:42:38 -04002425 /* ex1: ee_block to iblock - 1 : uninitialized */
2426 if (iblock > ee_block) {
2427 ex1 = ex;
2428 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2429 ext4_ext_mark_uninitialized(ex1);
2430 ex2 = &newex;
2431 }
2432 /*
2433 * for sanity, update the length of the ex2 extent before
2434 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2435 * overlap of blocks.
2436 */
2437 if (!ex1 && allocated > max_blocks)
2438 ex2->ee_len = cpu_to_le16(max_blocks);
2439 /* ex3: to ee_block + ee_len : uninitialised */
2440 if (allocated > max_blocks) {
2441 unsigned int newdepth;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002442 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
2443 if (allocated <= EXT4_EXT_ZERO_LEN) {
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002444 /*
2445 * iblock == ee_block is handled by the zerouout
2446 * at the beginning.
2447 * Mark first half uninitialized.
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002448 * Mark second half initialized and zero out the
2449 * initialized extent
2450 */
2451 ex->ee_block = orig_ex.ee_block;
2452 ex->ee_len = cpu_to_le16(ee_len - allocated);
2453 ext4_ext_mark_uninitialized(ex);
2454 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2455 ext4_ext_dirty(handle, inode, path + depth);
2456
2457 ex3 = &newex;
2458 ex3->ee_block = cpu_to_le32(iblock);
2459 ext4_ext_store_pblock(ex3, newblock);
2460 ex3->ee_len = cpu_to_le16(allocated);
2461 err = ext4_ext_insert_extent(handle, inode, path, ex3);
2462 if (err == -ENOSPC) {
2463 err = ext4_ext_zeroout(inode, &orig_ex);
2464 if (err)
2465 goto fix_extent_len;
2466 ex->ee_block = orig_ex.ee_block;
2467 ex->ee_len = orig_ex.ee_len;
2468 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2469 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002470 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002471 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002472
2473 } else if (err)
2474 goto fix_extent_len;
2475
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002476 /*
2477 * We need to zero out the second half because
2478 * an fallocate request can update file size and
2479 * converting the second half to initialized extent
2480 * implies that we can leak some junk data to user
2481 * space.
2482 */
2483 err = ext4_ext_zeroout(inode, ex3);
2484 if (err) {
2485 /*
2486 * We should actually mark the
2487 * second half as uninit and return error
2488 * Insert would have changed the extent
2489 */
2490 depth = ext_depth(inode);
2491 ext4_ext_drop_refs(path);
2492 path = ext4_ext_find_extent(inode,
2493 iblock, path);
2494 if (IS_ERR(path)) {
2495 err = PTR_ERR(path);
2496 return err;
2497 }
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002498 /* get the second half extent details */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002499 ex = path[depth].p_ext;
2500 err = ext4_ext_get_access(handle, inode,
2501 path + depth);
2502 if (err)
2503 return err;
2504 ext4_ext_mark_uninitialized(ex);
2505 ext4_ext_dirty(handle, inode, path + depth);
2506 return err;
2507 }
2508
2509 /* zeroed the second half */
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002510 return allocated;
2511 }
Amit Arora56055d32007-07-17 21:42:38 -04002512 ex3 = &newex;
2513 ex3->ee_block = cpu_to_le32(iblock + max_blocks);
2514 ext4_ext_store_pblock(ex3, newblock + max_blocks);
2515 ex3->ee_len = cpu_to_le16(allocated - max_blocks);
2516 ext4_ext_mark_uninitialized(ex3);
2517 err = ext4_ext_insert_extent(handle, inode, path, ex3);
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002518 if (err == -ENOSPC) {
2519 err = ext4_ext_zeroout(inode, &orig_ex);
2520 if (err)
2521 goto fix_extent_len;
2522 /* update the extent length and mark as initialized */
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002523 ex->ee_block = orig_ex.ee_block;
2524 ex->ee_len = orig_ex.ee_len;
2525 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002526 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002527 /* zeroed the full extent */
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002528 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002529 return allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002530
2531 } else if (err)
2532 goto fix_extent_len;
Amit Arora56055d32007-07-17 21:42:38 -04002533 /*
2534 * The depth, and hence eh & ex might change
2535 * as part of the insert above.
2536 */
2537 newdepth = ext_depth(inode);
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002538 /*
2539 * update the extent length after successfull insert of the
2540 * split extent
2541 */
2542 orig_ex.ee_len = cpu_to_le16(ee_len -
2543 ext4_ext_get_actual_len(ex3));
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002544 depth = newdepth;
2545 ext4_ext_drop_refs(path);
2546 path = ext4_ext_find_extent(inode, iblock, path);
2547 if (IS_ERR(path)) {
2548 err = PTR_ERR(path);
2549 goto out;
Amit Arora56055d32007-07-17 21:42:38 -04002550 }
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002551 eh = path[depth].p_hdr;
2552 ex = path[depth].p_ext;
2553 if (ex2 != &newex)
2554 ex2 = ex;
2555
2556 err = ext4_ext_get_access(handle, inode, path + depth);
2557 if (err)
2558 goto out;
2559
Amit Arora56055d32007-07-17 21:42:38 -04002560 allocated = max_blocks;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002561
2562 /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
2563 * to insert a extent in the middle zerout directly
2564 * otherwise give the extent a chance to merge to left
2565 */
2566 if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
2567 iblock != ee_block) {
2568 err = ext4_ext_zeroout(inode, &orig_ex);
2569 if (err)
2570 goto fix_extent_len;
2571 /* update the extent length and mark as initialized */
2572 ex->ee_block = orig_ex.ee_block;
2573 ex->ee_len = orig_ex.ee_len;
2574 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2575 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002576 /* zero out the first half */
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002577 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002578 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002579 }
Amit Arora56055d32007-07-17 21:42:38 -04002580 }
2581 /*
2582 * If there was a change of depth as part of the
2583 * insertion of ex3 above, we need to update the length
2584 * of the ex1 extent again here
2585 */
2586 if (ex1 && ex1 != ex) {
2587 ex1 = ex;
2588 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2589 ext4_ext_mark_uninitialized(ex1);
2590 ex2 = &newex;
2591 }
2592 /* ex2: iblock to iblock + maxblocks-1 : initialised */
2593 ex2->ee_block = cpu_to_le32(iblock);
Amit Arora56055d32007-07-17 21:42:38 -04002594 ext4_ext_store_pblock(ex2, newblock);
2595 ex2->ee_len = cpu_to_le16(allocated);
2596 if (ex2 != ex)
2597 goto insert;
Amit Arora56055d32007-07-17 21:42:38 -04002598 /*
2599 * New (initialized) extent starts from the first block
2600 * in the current extent. i.e., ex2 == ex
2601 * We have to see if it can be merged with the extent
2602 * on the left.
2603 */
2604 if (ex2 > EXT_FIRST_EXTENT(eh)) {
2605 /*
2606 * To merge left, pass "ex2 - 1" to try_to_merge(),
2607 * since it merges towards right _only_.
2608 */
2609 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
2610 if (ret) {
2611 err = ext4_ext_correct_indexes(handle, inode, path);
2612 if (err)
2613 goto out;
2614 depth = ext_depth(inode);
2615 ex2--;
2616 }
2617 }
2618 /*
2619 * Try to Merge towards right. This might be required
2620 * only when the whole extent is being written to.
2621 * i.e. ex2 == ex and ex3 == NULL.
2622 */
2623 if (!ex3) {
2624 ret = ext4_ext_try_to_merge(inode, path, ex2);
2625 if (ret) {
2626 err = ext4_ext_correct_indexes(handle, inode, path);
2627 if (err)
2628 goto out;
2629 }
2630 }
2631 /* Mark modified extent as dirty */
2632 err = ext4_ext_dirty(handle, inode, path + depth);
2633 goto out;
2634insert:
2635 err = ext4_ext_insert_extent(handle, inode, path, &newex);
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002636 if (err == -ENOSPC) {
2637 err = ext4_ext_zeroout(inode, &orig_ex);
2638 if (err)
2639 goto fix_extent_len;
2640 /* update the extent length and mark as initialized */
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002641 ex->ee_block = orig_ex.ee_block;
2642 ex->ee_len = orig_ex.ee_len;
2643 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002644 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002645 /* zero out the first half */
2646 return allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002647 } else if (err)
2648 goto fix_extent_len;
Amit Arora56055d32007-07-17 21:42:38 -04002649out:
2650 return err ? err : allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002651
2652fix_extent_len:
2653 ex->ee_block = orig_ex.ee_block;
2654 ex->ee_len = orig_ex.ee_len;
2655 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2656 ext4_ext_mark_uninitialized(ex);
2657 ext4_ext_dirty(handle, inode, path + depth);
2658 return err;
Amit Arora56055d32007-07-17 21:42:38 -04002659}
2660
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002661/*
Mingming Caof5ab0d12008-02-25 15:29:55 -05002662 * Block allocation/map/preallocation routine for extents based files
2663 *
2664 *
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002665 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05002666 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
2667 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
Mingming Caof5ab0d12008-02-25 15:29:55 -05002668 *
2669 * return > 0, number of of blocks already mapped/allocated
2670 * if create == 0 and these are pre-allocated blocks
2671 * buffer head is unmapped
2672 * otherwise blocks are mapped
2673 *
2674 * return = 0, if plain look up failed (blocks have not been allocated)
2675 * buffer head is unmapped
2676 *
2677 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002678 */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002679int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002680 ext4_lblk_t iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07002681 unsigned long max_blocks, struct buffer_head *bh_result,
2682 int create, int extend_disksize)
2683{
2684 struct ext4_ext_path *path = NULL;
Amit Arora56055d32007-07-17 21:42:38 -04002685 struct ext4_extent_header *eh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002686 struct ext4_extent newex, *ex;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002687 ext4_fsblk_t goal, newblock;
Amit Arora56055d32007-07-17 21:42:38 -04002688 int err = 0, depth, ret;
Alex Tomasa86c6182006-10-11 01:21:03 -07002689 unsigned long allocated = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05002690 struct ext4_allocation_request ar;
Mingming Cao61628a32008-07-11 19:27:31 -04002691 loff_t disksize;
Alex Tomasa86c6182006-10-11 01:21:03 -07002692
2693 __clear_bit(BH_New, &bh_result->b_state);
Eric Sandeenbba90742008-01-28 23:58:27 -05002694 ext_debug("blocks %u/%lu requested for inode %u\n",
2695 iblock, max_blocks, inode->i_ino);
Alex Tomasa86c6182006-10-11 01:21:03 -07002696
2697 /* check in cache */
Avantika Mathur7e028972006-12-06 20:41:33 -08002698 goal = ext4_ext_in_cache(inode, iblock, &newex);
2699 if (goal) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002700 if (goal == EXT4_EXT_CACHE_GAP) {
2701 if (!create) {
Amit Arora56055d32007-07-17 21:42:38 -04002702 /*
2703 * block isn't allocated yet and
2704 * user doesn't want to allocate it
2705 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002706 goto out2;
2707 }
2708 /* we should allocate requested block */
2709 } else if (goal == EXT4_EXT_CACHE_EXTENT) {
2710 /* block is already allocated */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002711 newblock = iblock
2712 - le32_to_cpu(newex.ee_block)
2713 + ext_pblock(&newex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002714 /* number of remaining blocks in the extent */
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002715 allocated = ext4_ext_get_actual_len(&newex) -
Alex Tomasa86c6182006-10-11 01:21:03 -07002716 (iblock - le32_to_cpu(newex.ee_block));
2717 goto out;
2718 } else {
2719 BUG();
2720 }
2721 }
2722
2723 /* find extent for this block */
2724 path = ext4_ext_find_extent(inode, iblock, NULL);
2725 if (IS_ERR(path)) {
2726 err = PTR_ERR(path);
2727 path = NULL;
2728 goto out2;
2729 }
2730
2731 depth = ext_depth(inode);
2732
2733 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002734 * consistent leaf must not be empty;
2735 * this situation is possible, though, _during_ tree modification;
Alex Tomasa86c6182006-10-11 01:21:03 -07002736 * this is why assert can't be put in ext4_ext_find_extent()
2737 */
2738 BUG_ON(path[depth].p_ext == NULL && depth != 0);
Amit Arora56055d32007-07-17 21:42:38 -04002739 eh = path[depth].p_hdr;
Alex Tomasa86c6182006-10-11 01:21:03 -07002740
Avantika Mathur7e028972006-12-06 20:41:33 -08002741 ex = path[depth].p_ext;
2742 if (ex) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002743 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002744 ext4_fsblk_t ee_start = ext_pblock(ex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002745 unsigned short ee_len;
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002746
2747 /*
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002748 * Uninitialized extents are treated as holes, except that
Amit Arora56055d32007-07-17 21:42:38 -04002749 * we split out initialized portions during a write.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07002750 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04002751 ee_len = ext4_ext_get_actual_len(ex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002752 /* if found extent covers block, simply return it */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04002753 if (iblock >= ee_block && iblock < ee_block + ee_len) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002754 newblock = iblock - ee_block + ee_start;
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002755 /* number of remaining blocks in the extent */
Alex Tomasa86c6182006-10-11 01:21:03 -07002756 allocated = ee_len - (iblock - ee_block);
Eric Sandeenbba90742008-01-28 23:58:27 -05002757 ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07002758 ee_block, ee_len, newblock);
Amit Arora56055d32007-07-17 21:42:38 -04002759
Amit Aroraa2df2a62007-07-17 21:42:41 -04002760 /* Do not put uninitialized extent in the cache */
Amit Arora56055d32007-07-17 21:42:38 -04002761 if (!ext4_ext_is_uninitialized(ex)) {
Amit Aroraa2df2a62007-07-17 21:42:41 -04002762 ext4_ext_put_in_cache(inode, ee_block,
2763 ee_len, ee_start,
2764 EXT4_EXT_CACHE_EXTENT);
Amit Arora56055d32007-07-17 21:42:38 -04002765 goto out;
2766 }
2767 if (create == EXT4_CREATE_UNINITIALIZED_EXT)
2768 goto out;
Aneesh Kumar K.Ve067ba02008-04-29 08:11:12 -04002769 if (!create) {
2770 /*
2771 * We have blocks reserved already. We
2772 * return allocated blocks so that delalloc
2773 * won't do block reservation for us. But
2774 * the buffer head will be unmapped so that
2775 * a read from the block returns 0s.
2776 */
2777 if (allocated > max_blocks)
2778 allocated = max_blocks;
Eric Sandeen953e6222008-07-11 19:27:31 -04002779 set_buffer_unwritten(bh_result);
Amit Arora56055d32007-07-17 21:42:38 -04002780 goto out2;
Aneesh Kumar K.Ve067ba02008-04-29 08:11:12 -04002781 }
Amit Arora56055d32007-07-17 21:42:38 -04002782
2783 ret = ext4_ext_convert_to_initialized(handle, inode,
2784 path, iblock,
2785 max_blocks);
Dmitry Monakhovdbf9d7d2008-01-28 23:58:27 -05002786 if (ret <= 0) {
2787 err = ret;
Amit Arora56055d32007-07-17 21:42:38 -04002788 goto out2;
Dmitry Monakhovdbf9d7d2008-01-28 23:58:27 -05002789 } else
Amit Arora56055d32007-07-17 21:42:38 -04002790 allocated = ret;
2791 goto outnew;
Alex Tomasa86c6182006-10-11 01:21:03 -07002792 }
2793 }
2794
2795 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002796 * requested block isn't allocated yet;
Alex Tomasa86c6182006-10-11 01:21:03 -07002797 * we couldn't try to create block if create flag is zero
2798 */
2799 if (!create) {
Amit Arora56055d32007-07-17 21:42:38 -04002800 /*
2801 * put just found gap into cache to speed up
2802 * subsequent requests
2803 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002804 ext4_ext_put_gap_in_cache(inode, path, iblock);
2805 goto out2;
2806 }
2807 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04002808 * Okay, we need to do block allocation.
Andrew Morton63f57932006-10-11 01:21:24 -07002809 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002810
Alex Tomasc9de5602008-01-29 00:19:52 -05002811 /* find neighbour allocated blocks */
2812 ar.lleft = iblock;
2813 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
2814 if (err)
2815 goto out2;
2816 ar.lright = iblock;
2817 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
2818 if (err)
2819 goto out2;
Amit Arora25d14f92007-05-24 13:04:13 -04002820
Amit Arora749269f2007-07-18 09:02:56 -04002821 /*
2822 * See if request is beyond maximum number of blocks we can have in
2823 * a single extent. For an initialized extent this limit is
2824 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
2825 * EXT_UNINIT_MAX_LEN.
2826 */
2827 if (max_blocks > EXT_INIT_MAX_LEN &&
2828 create != EXT4_CREATE_UNINITIALIZED_EXT)
2829 max_blocks = EXT_INIT_MAX_LEN;
2830 else if (max_blocks > EXT_UNINIT_MAX_LEN &&
2831 create == EXT4_CREATE_UNINITIALIZED_EXT)
2832 max_blocks = EXT_UNINIT_MAX_LEN;
2833
Amit Arora25d14f92007-05-24 13:04:13 -04002834 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
2835 newex.ee_block = cpu_to_le32(iblock);
2836 newex.ee_len = cpu_to_le16(max_blocks);
2837 err = ext4_ext_check_overlap(inode, &newex, path);
2838 if (err)
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002839 allocated = ext4_ext_get_actual_len(&newex);
Amit Arora25d14f92007-05-24 13:04:13 -04002840 else
2841 allocated = max_blocks;
Alex Tomasc9de5602008-01-29 00:19:52 -05002842
2843 /* allocate new block */
2844 ar.inode = inode;
2845 ar.goal = ext4_ext_find_goal(inode, path, iblock);
2846 ar.logical = iblock;
2847 ar.len = allocated;
2848 if (S_ISREG(inode->i_mode))
2849 ar.flags = EXT4_MB_HINT_DATA;
2850 else
2851 /* disable in-core preallocation for non-regular files */
2852 ar.flags = 0;
2853 newblock = ext4_mb_new_blocks(handle, &ar, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -07002854 if (!newblock)
2855 goto out2;
Mingming Cao2ae02102006-10-11 01:21:11 -07002856 ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07002857 goal, newblock, allocated);
2858
2859 /* try to insert new extent into found leaf and return */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002860 ext4_ext_store_pblock(&newex, newblock);
Alex Tomasc9de5602008-01-29 00:19:52 -05002861 newex.ee_len = cpu_to_le16(ar.len);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002862 if (create == EXT4_CREATE_UNINITIALIZED_EXT) /* Mark uninitialized */
2863 ext4_ext_mark_uninitialized(&newex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002864 err = ext4_ext_insert_extent(handle, inode, path, &newex);
Alex Tomas315054f2007-05-24 13:04:25 -04002865 if (err) {
2866 /* free data blocks we just allocated */
Alex Tomasc9de5602008-01-29 00:19:52 -05002867 /* not a good idea to call discard here directly,
2868 * but otherwise we'd need to call it every free() */
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04002869 ext4_discard_preallocations(inode);
Alex Tomas315054f2007-05-24 13:04:25 -04002870 ext4_free_blocks(handle, inode, ext_pblock(&newex),
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002871 ext4_ext_get_actual_len(&newex), 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07002872 goto out2;
Alex Tomas315054f2007-05-24 13:04:25 -04002873 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002874
Alex Tomasa86c6182006-10-11 01:21:03 -07002875 /* previous routine could use block we allocated */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002876 newblock = ext_pblock(&newex);
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05002877 allocated = ext4_ext_get_actual_len(&newex);
Amit Arora56055d32007-07-17 21:42:38 -04002878outnew:
Mingming Cao61628a32008-07-11 19:27:31 -04002879 if (extend_disksize) {
2880 disksize = ((loff_t) iblock + ar.len) << inode->i_blkbits;
2881 if (disksize > i_size_read(inode))
2882 disksize = i_size_read(inode);
2883 if (disksize > EXT4_I(inode)->i_disksize)
2884 EXT4_I(inode)->i_disksize = disksize;
2885 }
Aneesh Kumar K.Va379cd12008-07-11 19:27:31 -04002886
Eric Sandeen953e6222008-07-11 19:27:31 -04002887 set_buffer_new(bh_result);
Alex Tomasa86c6182006-10-11 01:21:03 -07002888
Amit Aroraa2df2a62007-07-17 21:42:41 -04002889 /* Cache only when it is _not_ an uninitialized extent */
2890 if (create != EXT4_CREATE_UNINITIALIZED_EXT)
2891 ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
2892 EXT4_EXT_CACHE_EXTENT);
Alex Tomasa86c6182006-10-11 01:21:03 -07002893out:
2894 if (allocated > max_blocks)
2895 allocated = max_blocks;
2896 ext4_ext_show_leaf(inode, path);
Eric Sandeen953e6222008-07-11 19:27:31 -04002897 set_buffer_mapped(bh_result);
Alex Tomasa86c6182006-10-11 01:21:03 -07002898 bh_result->b_bdev = inode->i_sb->s_bdev;
2899 bh_result->b_blocknr = newblock;
2900out2:
2901 if (path) {
2902 ext4_ext_drop_refs(path);
2903 kfree(path);
2904 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002905 return err ? err : allocated;
2906}
2907
Jan Karacf108bc2008-07-11 19:27:31 -04002908void ext4_ext_truncate(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -07002909{
2910 struct address_space *mapping = inode->i_mapping;
2911 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002912 ext4_lblk_t last_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07002913 handle_t *handle;
2914 int err = 0;
2915
2916 /*
2917 * probably first extent we're gonna free will be last in block
2918 */
Mingming Caof3bd1f32008-08-19 22:16:03 -04002919 err = ext4_writepage_trans_blocks(inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07002920 handle = ext4_journal_start(inode, err);
Jan Karacf108bc2008-07-11 19:27:31 -04002921 if (IS_ERR(handle))
Alex Tomasa86c6182006-10-11 01:21:03 -07002922 return;
Alex Tomasa86c6182006-10-11 01:21:03 -07002923
Jan Karacf108bc2008-07-11 19:27:31 -04002924 if (inode->i_size & (sb->s_blocksize - 1))
2925 ext4_block_truncate_page(handle, mapping, inode->i_size);
Alex Tomasa86c6182006-10-11 01:21:03 -07002926
Jan Kara9ddfc3d2008-07-11 19:27:31 -04002927 if (ext4_orphan_add(handle, inode))
2928 goto out_stop;
2929
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05002930 down_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07002931 ext4_ext_invalidate_cache(inode);
2932
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04002933 ext4_discard_preallocations(inode);
Alex Tomasc9de5602008-01-29 00:19:52 -05002934
Alex Tomasa86c6182006-10-11 01:21:03 -07002935 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002936 * TODO: optimization is possible here.
2937 * Probably we need not scan at all,
2938 * because page truncation is enough.
Alex Tomasa86c6182006-10-11 01:21:03 -07002939 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002940
2941 /* we have to know where to truncate from in crash case */
2942 EXT4_I(inode)->i_disksize = inode->i_size;
2943 ext4_mark_inode_dirty(handle, inode);
2944
2945 last_block = (inode->i_size + sb->s_blocksize - 1)
2946 >> EXT4_BLOCK_SIZE_BITS(sb);
2947 err = ext4_ext_remove_space(inode, last_block);
2948
2949 /* In a multi-transaction truncate, we only make the final
Amit Arora56055d32007-07-17 21:42:38 -04002950 * transaction synchronous.
2951 */
Alex Tomasa86c6182006-10-11 01:21:03 -07002952 if (IS_SYNC(inode))
2953 handle->h_sync = 1;
2954
2955out_stop:
Jan Kara9ddfc3d2008-07-11 19:27:31 -04002956 up_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07002957 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002958 * If this was a simple ftruncate() and the file will remain alive,
Alex Tomasa86c6182006-10-11 01:21:03 -07002959 * then we need to clear up the orphan record which we created above.
2960 * However, if this was a real unlink then we were called by
2961 * ext4_delete_inode(), and we allow that function to clean up the
2962 * orphan info for us.
2963 */
2964 if (inode->i_nlink)
2965 ext4_orphan_del(handle, inode);
2966
Solofo Ramangalahyef737722008-04-29 22:00:41 -04002967 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
2968 ext4_mark_inode_dirty(handle, inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07002969 ext4_journal_stop(handle);
2970}
2971
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04002972static void ext4_falloc_update_inode(struct inode *inode,
2973 int mode, loff_t new_size, int update_ctime)
2974{
2975 struct timespec now;
2976
2977 if (update_ctime) {
2978 now = current_fs_time(inode->i_sb);
2979 if (!timespec_equal(&inode->i_ctime, &now))
2980 inode->i_ctime = now;
2981 }
2982 /*
2983 * Update only when preallocation was requested beyond
2984 * the file size.
2985 */
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04002986 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
2987 if (new_size > i_size_read(inode))
2988 i_size_write(inode, new_size);
2989 if (new_size > EXT4_I(inode)->i_disksize)
2990 ext4_update_i_disksize(inode, new_size);
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04002991 }
2992
2993}
2994
Amit Aroraa2df2a62007-07-17 21:42:41 -04002995/*
2996 * preallocate space for a file. This implements ext4's fallocate inode
2997 * operation, which gets called from sys_fallocate system call.
2998 * For block-mapped files, posix_fallocate should fall back to the method
2999 * of writing zeroes to the required new blocks (the same behavior which is
3000 * expected for file systems which do not support fallocate() system call).
3001 */
3002long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
3003{
3004 handle_t *handle;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003005 ext4_lblk_t block;
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003006 loff_t new_size;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003007 unsigned long max_blocks;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003008 int ret = 0;
3009 int ret2 = 0;
3010 int retries = 0;
3011 struct buffer_head map_bh;
3012 unsigned int credits, blkbits = inode->i_blkbits;
3013
3014 /*
3015 * currently supporting (pre)allocate mode for extent-based
3016 * files _only_
3017 */
3018 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3019 return -EOPNOTSUPP;
3020
3021 /* preallocation to directories is currently not supported */
3022 if (S_ISDIR(inode->i_mode))
3023 return -ENODEV;
3024
3025 block = offset >> blkbits;
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003026 /*
3027 * We can't just convert len to max_blocks because
3028 * If blocksize = 4096 offset = 3072 and len = 2048
3029 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04003030 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003031 - block;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003032 /*
Mingming Caof3bd1f32008-08-19 22:16:03 -04003033 * credits to insert 1 extent into extent tree
Amit Aroraa2df2a62007-07-17 21:42:41 -04003034 */
Mingming Caof3bd1f32008-08-19 22:16:03 -04003035 credits = ext4_chunk_trans_blocks(inode, max_blocks);
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05003036 mutex_lock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04003037retry:
3038 while (ret >= 0 && ret < max_blocks) {
3039 block = block + ret;
3040 max_blocks = max_blocks - ret;
3041 handle = ext4_journal_start(inode, credits);
3042 if (IS_ERR(handle)) {
3043 ret = PTR_ERR(handle);
3044 break;
3045 }
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05003046 ret = ext4_get_blocks_wrap(handle, inode, block,
Amit Aroraa2df2a62007-07-17 21:42:41 -04003047 max_blocks, &map_bh,
Mingming Caod2a17632008-07-14 17:52:37 -04003048 EXT4_CREATE_UNINITIALIZED_EXT, 0, 0);
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05003049 if (ret <= 0) {
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05003050#ifdef EXT4FS_DEBUG
3051 WARN_ON(ret <= 0);
3052 printk(KERN_ERR "%s: ext4_ext_get_blocks "
3053 "returned error inode#%lu, block=%u, "
3054 "max_blocks=%lu", __func__,
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05003055 inode->i_ino, block, max_blocks);
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05003056#endif
Amit Aroraa2df2a62007-07-17 21:42:41 -04003057 ext4_mark_inode_dirty(handle, inode);
3058 ret2 = ext4_journal_stop(handle);
3059 break;
3060 }
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003061 if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
3062 blkbits) >> blkbits))
3063 new_size = offset + len;
3064 else
3065 new_size = (block + ret) << blkbits;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003066
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003067 ext4_falloc_update_inode(inode, mode, new_size,
3068 buffer_new(&map_bh));
Amit Aroraa2df2a62007-07-17 21:42:41 -04003069 ext4_mark_inode_dirty(handle, inode);
3070 ret2 = ext4_journal_stop(handle);
3071 if (ret2)
3072 break;
3073 }
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003074 if (ret == -ENOSPC &&
3075 ext4_should_retry_alloc(inode->i_sb, &retries)) {
3076 ret = 0;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003077 goto retry;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003078 }
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05003079 mutex_unlock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04003080 return ret > 0 ? ret2 : ret;
3081}
Eric Sandeen6873fa02008-10-07 00:46:36 -04003082
3083/*
3084 * Callback function called for each extent to gather FIEMAP information.
3085 */
3086int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,
3087 struct ext4_ext_cache *newex, struct ext4_extent *ex,
3088 void *data)
3089{
3090 struct fiemap_extent_info *fieinfo = data;
3091 unsigned long blksize_bits = inode->i_sb->s_blocksize_bits;
3092 __u64 logical;
3093 __u64 physical;
3094 __u64 length;
3095 __u32 flags = 0;
3096 int error;
3097
3098 logical = (__u64)newex->ec_block << blksize_bits;
3099
3100 if (newex->ec_type == EXT4_EXT_CACHE_GAP) {
3101 pgoff_t offset;
3102 struct page *page;
3103 struct buffer_head *bh = NULL;
3104
3105 offset = logical >> PAGE_SHIFT;
3106 page = find_get_page(inode->i_mapping, offset);
3107 if (!page || !page_has_buffers(page))
3108 return EXT_CONTINUE;
3109
3110 bh = page_buffers(page);
3111
3112 if (!bh)
3113 return EXT_CONTINUE;
3114
3115 if (buffer_delay(bh)) {
3116 flags |= FIEMAP_EXTENT_DELALLOC;
3117 page_cache_release(page);
3118 } else {
3119 page_cache_release(page);
3120 return EXT_CONTINUE;
3121 }
3122 }
3123
3124 physical = (__u64)newex->ec_start << blksize_bits;
3125 length = (__u64)newex->ec_len << blksize_bits;
3126
3127 if (ex && ext4_ext_is_uninitialized(ex))
3128 flags |= FIEMAP_EXTENT_UNWRITTEN;
3129
3130 /*
3131 * If this extent reaches EXT_MAX_BLOCK, it must be last.
3132 *
3133 * Or if ext4_ext_next_allocated_block is EXT_MAX_BLOCK,
3134 * this also indicates no more allocated blocks.
3135 *
3136 * XXX this might miss a single-block extent at EXT_MAX_BLOCK
3137 */
3138 if (logical + length - 1 == EXT_MAX_BLOCK ||
3139 ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
3140 flags |= FIEMAP_EXTENT_LAST;
3141
3142 error = fiemap_fill_next_extent(fieinfo, logical, physical,
3143 length, flags);
3144 if (error < 0)
3145 return error;
3146 if (error == 1)
3147 return EXT_BREAK;
3148
3149 return EXT_CONTINUE;
3150}
3151
3152/* fiemap flags we can handle specified here */
3153#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
3154
3155int ext4_xattr_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo)
3156{
3157 __u64 physical = 0;
3158 __u64 length;
3159 __u32 flags = FIEMAP_EXTENT_LAST;
3160 int blockbits = inode->i_sb->s_blocksize_bits;
3161 int error = 0;
3162
3163 /* in-inode? */
3164 if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
3165 struct ext4_iloc iloc;
3166 int offset; /* offset of xattr in inode */
3167
3168 error = ext4_get_inode_loc(inode, &iloc);
3169 if (error)
3170 return error;
3171 physical = iloc.bh->b_blocknr << blockbits;
3172 offset = EXT4_GOOD_OLD_INODE_SIZE +
3173 EXT4_I(inode)->i_extra_isize;
3174 physical += offset;
3175 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
3176 flags |= FIEMAP_EXTENT_DATA_INLINE;
3177 } else { /* external block */
3178 physical = EXT4_I(inode)->i_file_acl << blockbits;
3179 length = inode->i_sb->s_blocksize;
3180 }
3181
3182 if (physical)
3183 error = fiemap_fill_next_extent(fieinfo, 0, physical,
3184 length, flags);
3185 return (error < 0 ? error : 0);
3186}
3187
3188int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3189 __u64 start, __u64 len)
3190{
3191 ext4_lblk_t start_blk;
3192 ext4_lblk_t len_blks;
3193 int error = 0;
3194
3195 /* fallback to generic here if not in extents fmt */
3196 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3197 return generic_block_fiemap(inode, fieinfo, start, len,
3198 ext4_get_block);
3199
3200 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
3201 return -EBADR;
3202
3203 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
3204 error = ext4_xattr_fiemap(inode, fieinfo);
3205 } else {
3206 start_blk = start >> inode->i_sb->s_blocksize_bits;
3207 len_blks = len >> inode->i_sb->s_blocksize_bits;
3208
3209 /*
3210 * Walk the extent tree gathering extent information.
3211 * ext4_ext_fiemap_cb will push extents back to user.
3212 */
3213 down_write(&EXT4_I(inode)->i_data_sem);
3214 error = ext4_ext_walk_space(inode, start_blk, len_blks,
3215 ext4_ext_fiemap_cb, fieinfo);
3216 up_write(&EXT4_I(inode)->i_data_sem);
3217 }
3218
3219 return error;
3220}
3221