blob: 715264b4bae4b421c110af69ed3ccf8dc32bb1f6 [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 */
Akira Fujita748de672009-06-17 19:24:03 -040052ext4_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
Jan Kara487caee2009-08-17 22:17:20 -040096static int ext4_ext_truncate_extend_restart(handle_t *handle,
97 struct inode *inode,
98 int needed)
Alex Tomasa86c6182006-10-11 01:21:03 -070099{
100 int err;
101
Frank Mayhar03901312009-01-07 00:06:22 -0500102 if (!ext4_handle_valid(handle))
103 return 0;
Alex Tomasa86c6182006-10-11 01:21:03 -0700104 if (handle->h_buffer_credits > needed)
Shen Feng9102e4f2008-07-11 19:27:31 -0400105 return 0;
106 err = ext4_journal_extend(handle, needed);
Theodore Ts'o0123c932008-08-01 20:57:54 -0400107 if (err <= 0)
Shen Feng9102e4f2008-07-11 19:27:31 -0400108 return err;
Jan Kara487caee2009-08-17 22:17:20 -0400109 err = ext4_truncate_restart_trans(handle, inode, needed);
110 /*
111 * We have dropped i_data_sem so someone might have cached again
112 * an extent we are going to truncate.
113 */
114 ext4_ext_invalidate_cache(inode);
115
116 return err;
Alex Tomasa86c6182006-10-11 01:21:03 -0700117}
118
119/*
120 * could return:
121 * - EROFS
122 * - ENOMEM
123 */
124static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
125 struct ext4_ext_path *path)
126{
127 if (path->p_bh) {
128 /* path points to block */
129 return ext4_journal_get_write_access(handle, path->p_bh);
130 }
131 /* path points to leaf/index in inode body */
132 /* we use in-core data, no need to protect them */
133 return 0;
134}
135
136/*
137 * could return:
138 * - EROFS
139 * - ENOMEM
140 * - EIO
141 */
142static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
143 struct ext4_ext_path *path)
144{
145 int err;
146 if (path->p_bh) {
147 /* path points to block */
Frank Mayhar03901312009-01-07 00:06:22 -0500148 err = ext4_handle_dirty_metadata(handle, inode, path->p_bh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700149 } else {
150 /* path points to leaf/index in inode body */
151 err = ext4_mark_inode_dirty(handle, inode);
152 }
153 return err;
154}
155
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700156static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700157 struct ext4_ext_path *path,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500158 ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700159{
160 struct ext4_inode_info *ei = EXT4_I(inode);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700161 ext4_fsblk_t bg_start;
Valerie Clement74d34872008-02-15 13:43:07 -0500162 ext4_fsblk_t last_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700163 ext4_grpblk_t colour;
Theodore Ts'oa4912122009-03-12 12:18:34 -0400164 ext4_group_t block_group;
165 int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
Alex Tomasa86c6182006-10-11 01:21:03 -0700166 int depth;
167
168 if (path) {
169 struct ext4_extent *ex;
170 depth = path->p_depth;
171
172 /* try to predict block placement */
Avantika Mathur7e028972006-12-06 20:41:33 -0800173 ex = path[depth].p_ext;
174 if (ex)
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700175 return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700176
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700177 /* it looks like index is empty;
178 * try to find starting block from index itself */
Alex Tomasa86c6182006-10-11 01:21:03 -0700179 if (path[depth].p_bh)
180 return path[depth].p_bh->b_blocknr;
181 }
182
183 /* OK. use inode's group */
Theodore Ts'oa4912122009-03-12 12:18:34 -0400184 block_group = ei->i_block_group;
185 if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
186 /*
187 * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
188 * block groups per flexgroup, reserve the first block
189 * group for directories and special files. Regular
190 * files will start at the second block group. This
191 * tends to speed up directory access and improves
192 * fsck times.
193 */
194 block_group &= ~(flex_size-1);
195 if (S_ISREG(inode->i_mode))
196 block_group++;
197 }
198 bg_start = (block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) +
Alex Tomasa86c6182006-10-11 01:21:03 -0700199 le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block);
Valerie Clement74d34872008-02-15 13:43:07 -0500200 last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
201
Theodore Ts'oa4912122009-03-12 12:18:34 -0400202 /*
203 * If we are doing delayed allocation, we don't need take
204 * colour into account.
205 */
206 if (test_opt(inode->i_sb, DELALLOC))
207 return bg_start;
208
Valerie Clement74d34872008-02-15 13:43:07 -0500209 if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
210 colour = (current->pid % 16) *
Alex Tomasa86c6182006-10-11 01:21:03 -0700211 (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
Valerie Clement74d34872008-02-15 13:43:07 -0500212 else
213 colour = (current->pid % 16) * ((last_block - bg_start) / 16);
Alex Tomasa86c6182006-10-11 01:21:03 -0700214 return bg_start + colour + block;
215}
216
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400217/*
218 * Allocation for a meta data block
219 */
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700220static ext4_fsblk_t
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400221ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700222 struct ext4_ext_path *path,
223 struct ext4_extent *ex, int *err)
224{
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700225 ext4_fsblk_t goal, newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700226
227 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
Theodore Ts'o97df5d12008-12-12 12:41:28 -0500228 newblock = ext4_new_meta_blocks(handle, inode, goal, NULL, err);
Alex Tomasa86c6182006-10-11 01:21:03 -0700229 return newblock;
230}
231
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400232static inline int ext4_ext_space_block(struct inode *inode, int check)
Alex Tomasa86c6182006-10-11 01:21:03 -0700233{
234 int size;
235
236 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
237 / sizeof(struct ext4_extent);
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400238 if (!check) {
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100239#ifdef AGGRESSIVE_TEST
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400240 if (size > 6)
241 size = 6;
Alex Tomasa86c6182006-10-11 01:21:03 -0700242#endif
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400243 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700244 return size;
245}
246
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400247static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
Alex Tomasa86c6182006-10-11 01:21:03 -0700248{
249 int size;
250
251 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
252 / sizeof(struct ext4_extent_idx);
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400253 if (!check) {
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100254#ifdef AGGRESSIVE_TEST
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400255 if (size > 5)
256 size = 5;
Alex Tomasa86c6182006-10-11 01:21:03 -0700257#endif
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400258 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700259 return size;
260}
261
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400262static inline int ext4_ext_space_root(struct inode *inode, int check)
Alex Tomasa86c6182006-10-11 01:21:03 -0700263{
264 int size;
265
266 size = sizeof(EXT4_I(inode)->i_data);
267 size -= sizeof(struct ext4_extent_header);
268 size /= sizeof(struct ext4_extent);
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400269 if (!check) {
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100270#ifdef AGGRESSIVE_TEST
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400271 if (size > 3)
272 size = 3;
Alex Tomasa86c6182006-10-11 01:21:03 -0700273#endif
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400274 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700275 return size;
276}
277
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400278static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
Alex Tomasa86c6182006-10-11 01:21:03 -0700279{
280 int size;
281
282 size = sizeof(EXT4_I(inode)->i_data);
283 size -= sizeof(struct ext4_extent_header);
284 size /= sizeof(struct ext4_extent_idx);
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400285 if (!check) {
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +0100286#ifdef AGGRESSIVE_TEST
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400287 if (size > 4)
288 size = 4;
Alex Tomasa86c6182006-10-11 01:21:03 -0700289#endif
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400290 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700291 return size;
292}
293
Mingming Caod2a17632008-07-14 17:52:37 -0400294/*
295 * Calculate the number of metadata blocks needed
296 * to allocate @blocks
297 * Worse case is one block per extent
298 */
299int ext4_ext_calc_metadata_amount(struct inode *inode, int blocks)
300{
301 int lcap, icap, rcap, leafs, idxs, num;
302 int newextents = blocks;
303
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400304 rcap = ext4_ext_space_root_idx(inode, 0);
305 lcap = ext4_ext_space_block(inode, 0);
306 icap = ext4_ext_space_block_idx(inode, 0);
Mingming Caod2a17632008-07-14 17:52:37 -0400307
308 /* number of new leaf blocks needed */
309 num = leafs = (newextents + lcap - 1) / lcap;
310
311 /*
312 * Worse case, we need separate index block(s)
313 * to link all new leaf blocks
314 */
315 idxs = (leafs + icap - 1) / icap;
316 do {
317 num += idxs;
318 idxs = (idxs + icap - 1) / icap;
319 } while (idxs > rcap);
320
321 return num;
322}
323
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400324static int
325ext4_ext_max_entries(struct inode *inode, int depth)
326{
327 int max;
328
329 if (depth == ext_depth(inode)) {
330 if (depth == 0)
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400331 max = ext4_ext_space_root(inode, 1);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400332 else
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400333 max = ext4_ext_space_root_idx(inode, 1);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400334 } else {
335 if (depth == 0)
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400336 max = ext4_ext_space_block(inode, 1);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400337 else
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400338 max = ext4_ext_space_block_idx(inode, 1);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400339 }
340
341 return max;
342}
343
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400344static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
345{
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400346 ext4_fsblk_t block = ext_pblock(ext);
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400347 int len = ext4_ext_get_actual_len(ext);
Theodore Ts'oe84a26c2009-04-22 20:52:25 -0400348
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400349 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400350}
351
352static int ext4_valid_extent_idx(struct inode *inode,
353 struct ext4_extent_idx *ext_idx)
354{
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400355 ext4_fsblk_t block = idx_pblock(ext_idx);
Theodore Ts'oe84a26c2009-04-22 20:52:25 -0400356
Theodore Ts'o6fd058f2009-05-17 15:38:01 -0400357 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400358}
359
360static int ext4_valid_extent_entries(struct inode *inode,
361 struct ext4_extent_header *eh,
362 int depth)
363{
364 struct ext4_extent *ext;
365 struct ext4_extent_idx *ext_idx;
366 unsigned short entries;
367 if (eh->eh_entries == 0)
368 return 1;
369
370 entries = le16_to_cpu(eh->eh_entries);
371
372 if (depth == 0) {
373 /* leaf entries */
374 ext = EXT_FIRST_EXTENT(eh);
375 while (entries) {
376 if (!ext4_valid_extent(inode, ext))
377 return 0;
378 ext++;
379 entries--;
380 }
381 } else {
382 ext_idx = EXT_FIRST_INDEX(eh);
383 while (entries) {
384 if (!ext4_valid_extent_idx(inode, ext_idx))
385 return 0;
386 ext_idx++;
387 entries--;
388 }
389 }
390 return 1;
391}
392
393static int __ext4_ext_check(const char *function, struct inode *inode,
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400394 struct ext4_extent_header *eh,
395 int depth)
396{
397 const char *error_msg;
398 int max = 0;
399
400 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
401 error_msg = "invalid magic";
402 goto corrupted;
403 }
404 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
405 error_msg = "unexpected eh_depth";
406 goto corrupted;
407 }
408 if (unlikely(eh->eh_max == 0)) {
409 error_msg = "invalid eh_max";
410 goto corrupted;
411 }
412 max = ext4_ext_max_entries(inode, depth);
413 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
414 error_msg = "too large eh_max";
415 goto corrupted;
416 }
417 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
418 error_msg = "invalid eh_entries";
419 goto corrupted;
420 }
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400421 if (!ext4_valid_extent_entries(inode, eh, depth)) {
422 error_msg = "invalid extent entries";
423 goto corrupted;
424 }
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400425 return 0;
426
427corrupted:
428 ext4_error(inode->i_sb, function,
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400429 "bad header/extent in inode #%lu: %s - magic %x, "
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400430 "entries %u, max %u(%u), depth %u(%u)",
431 inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic),
432 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
433 max, le16_to_cpu(eh->eh_depth), depth);
434
435 return -EIO;
436}
437
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -0400438#define ext4_ext_check(inode, eh, depth) \
439 __ext4_ext_check(__func__, inode, eh, depth)
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400440
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -0400441int ext4_ext_check_inode(struct inode *inode)
442{
443 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
444}
445
Alex Tomasa86c6182006-10-11 01:21:03 -0700446#ifdef EXT_DEBUG
447static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
448{
449 int k, l = path->p_depth;
450
451 ext_debug("path:");
452 for (k = 0; k <= l; k++, path++) {
453 if (path->p_idx) {
Mingming Cao2ae02102006-10-11 01:21:11 -0700454 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700455 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700456 } else if (path->p_ext) {
Mingming553f9002009-09-18 13:34:55 -0400457 ext_debug(" %d:[%d]%d:%llu ",
Alex Tomasa86c6182006-10-11 01:21:03 -0700458 le32_to_cpu(path->p_ext->ee_block),
Mingming553f9002009-09-18 13:34:55 -0400459 ext4_ext_is_uninitialized(path->p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400460 ext4_ext_get_actual_len(path->p_ext),
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700461 ext_pblock(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700462 } else
463 ext_debug(" []");
464 }
465 ext_debug("\n");
466}
467
468static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
469{
470 int depth = ext_depth(inode);
471 struct ext4_extent_header *eh;
472 struct ext4_extent *ex;
473 int i;
474
475 if (!path)
476 return;
477
478 eh = path[depth].p_hdr;
479 ex = EXT_FIRST_EXTENT(eh);
480
Mingming553f9002009-09-18 13:34:55 -0400481 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
482
Alex Tomasa86c6182006-10-11 01:21:03 -0700483 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
Mingming553f9002009-09-18 13:34:55 -0400484 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
485 ext4_ext_is_uninitialized(ex),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400486 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -0700487 }
488 ext_debug("\n");
489}
490#else
Theodore Ts'oaf5bc922008-09-08 22:25:24 -0400491#define ext4_ext_show_path(inode, path)
492#define ext4_ext_show_leaf(inode, path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700493#endif
494
Aneesh Kumar K.Vb35905c2008-02-25 16:54:37 -0500495void ext4_ext_drop_refs(struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700496{
497 int depth = path->p_depth;
498 int i;
499
500 for (i = 0; i <= depth; i++, path++)
501 if (path->p_bh) {
502 brelse(path->p_bh);
503 path->p_bh = NULL;
504 }
505}
506
507/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700508 * ext4_ext_binsearch_idx:
509 * binary search for the closest index of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400510 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700511 */
512static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500513ext4_ext_binsearch_idx(struct inode *inode,
514 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700515{
516 struct ext4_extent_header *eh = path->p_hdr;
517 struct ext4_extent_idx *r, *l, *m;
518
Alex Tomasa86c6182006-10-11 01:21:03 -0700519
Eric Sandeenbba90742008-01-28 23:58:27 -0500520 ext_debug("binsearch for %u(idx): ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700521
522 l = EXT_FIRST_INDEX(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400523 r = EXT_LAST_INDEX(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700524 while (l <= r) {
525 m = l + (r - l) / 2;
526 if (block < le32_to_cpu(m->ei_block))
527 r = m - 1;
528 else
529 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400530 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
531 m, le32_to_cpu(m->ei_block),
532 r, le32_to_cpu(r->ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700533 }
534
535 path->p_idx = l - 1;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700536 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400537 idx_pblock(path->p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -0700538
539#ifdef CHECK_BINSEARCH
540 {
541 struct ext4_extent_idx *chix, *ix;
542 int k;
543
544 chix = ix = EXT_FIRST_INDEX(eh);
545 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
546 if (k != 0 &&
547 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
Theodore Ts'o4776004f2008-09-08 23:00:52 -0400548 printk(KERN_DEBUG "k=%d, ix=0x%p, "
549 "first=0x%p\n", k,
550 ix, EXT_FIRST_INDEX(eh));
551 printk(KERN_DEBUG "%u <= %u\n",
Alex Tomasa86c6182006-10-11 01:21:03 -0700552 le32_to_cpu(ix->ei_block),
553 le32_to_cpu(ix[-1].ei_block));
554 }
555 BUG_ON(k && le32_to_cpu(ix->ei_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400556 <= le32_to_cpu(ix[-1].ei_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700557 if (block < le32_to_cpu(ix->ei_block))
558 break;
559 chix = ix;
560 }
561 BUG_ON(chix != path->p_idx);
562 }
563#endif
564
565}
566
567/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700568 * ext4_ext_binsearch:
569 * binary search for closest extent of the given block
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400570 * the header must be checked before calling this
Alex Tomasa86c6182006-10-11 01:21:03 -0700571 */
572static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500573ext4_ext_binsearch(struct inode *inode,
574 struct ext4_ext_path *path, ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -0700575{
576 struct ext4_extent_header *eh = path->p_hdr;
577 struct ext4_extent *r, *l, *m;
578
Alex Tomasa86c6182006-10-11 01:21:03 -0700579 if (eh->eh_entries == 0) {
580 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700581 * this leaf is empty:
582 * we get such a leaf in split/add case
Alex Tomasa86c6182006-10-11 01:21:03 -0700583 */
584 return;
585 }
586
Eric Sandeenbba90742008-01-28 23:58:27 -0500587 ext_debug("binsearch for %u: ", block);
Alex Tomasa86c6182006-10-11 01:21:03 -0700588
589 l = EXT_FIRST_EXTENT(eh) + 1;
Dmitry Monakhove9f410b2007-07-18 09:09:15 -0400590 r = EXT_LAST_EXTENT(eh);
Alex Tomasa86c6182006-10-11 01:21:03 -0700591
592 while (l <= r) {
593 m = l + (r - l) / 2;
594 if (block < le32_to_cpu(m->ee_block))
595 r = m - 1;
596 else
597 l = m + 1;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400598 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
599 m, le32_to_cpu(m->ee_block),
600 r, le32_to_cpu(r->ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700601 }
602
603 path->p_ext = l - 1;
Mingming553f9002009-09-18 13:34:55 -0400604 ext_debug(" -> %d:%llu:[%d]%d ",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400605 le32_to_cpu(path->p_ext->ee_block),
606 ext_pblock(path->p_ext),
Mingming553f9002009-09-18 13:34:55 -0400607 ext4_ext_is_uninitialized(path->p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400608 ext4_ext_get_actual_len(path->p_ext));
Alex Tomasa86c6182006-10-11 01:21:03 -0700609
610#ifdef CHECK_BINSEARCH
611 {
612 struct ext4_extent *chex, *ex;
613 int k;
614
615 chex = ex = EXT_FIRST_EXTENT(eh);
616 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
617 BUG_ON(k && le32_to_cpu(ex->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400618 <= le32_to_cpu(ex[-1].ee_block));
Alex Tomasa86c6182006-10-11 01:21:03 -0700619 if (block < le32_to_cpu(ex->ee_block))
620 break;
621 chex = ex;
622 }
623 BUG_ON(chex != path->p_ext);
624 }
625#endif
626
627}
628
629int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
630{
631 struct ext4_extent_header *eh;
632
633 eh = ext_inode_hdr(inode);
634 eh->eh_depth = 0;
635 eh->eh_entries = 0;
636 eh->eh_magic = EXT4_EXT_MAGIC;
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400637 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -0700638 ext4_mark_inode_dirty(handle, inode);
639 ext4_ext_invalidate_cache(inode);
640 return 0;
641}
642
643struct ext4_ext_path *
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -0500644ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
645 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -0700646{
647 struct ext4_extent_header *eh;
648 struct buffer_head *bh;
649 short int depth, i, ppos = 0, alloc = 0;
650
651 eh = ext_inode_hdr(inode);
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400652 depth = ext_depth(inode);
Alex Tomasa86c6182006-10-11 01:21:03 -0700653
654 /* account possible depth increase */
655 if (!path) {
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800656 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
Alex Tomasa86c6182006-10-11 01:21:03 -0700657 GFP_NOFS);
658 if (!path)
659 return ERR_PTR(-ENOMEM);
660 alloc = 1;
661 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700662 path[0].p_hdr = eh;
Shen Feng1973adc2008-07-11 19:27:31 -0400663 path[0].p_bh = NULL;
Alex Tomasa86c6182006-10-11 01:21:03 -0700664
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400665 i = depth;
Alex Tomasa86c6182006-10-11 01:21:03 -0700666 /* walk through the tree */
667 while (i) {
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -0400668 int need_to_validate = 0;
669
Alex Tomasa86c6182006-10-11 01:21:03 -0700670 ext_debug("depth %d: num %d, max %d\n",
671 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
Alex Tomasc29c0ae2007-07-18 09:19:09 -0400672
Alex Tomasa86c6182006-10-11 01:21:03 -0700673 ext4_ext_binsearch_idx(inode, path + ppos, block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700674 path[ppos].p_block = idx_pblock(path[ppos].p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -0700675 path[ppos].p_depth = i;
676 path[ppos].p_ext = NULL;
677
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -0400678 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
679 if (unlikely(!bh))
Alex Tomasa86c6182006-10-11 01:21:03 -0700680 goto err;
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -0400681 if (!bh_uptodate_or_lock(bh)) {
682 if (bh_submit_read(bh) < 0) {
683 put_bh(bh);
684 goto err;
685 }
686 /* validate the extent entries */
687 need_to_validate = 1;
688 }
Alex Tomasa86c6182006-10-11 01:21:03 -0700689 eh = ext_block_hdr(bh);
690 ppos++;
691 BUG_ON(ppos > depth);
692 path[ppos].p_bh = bh;
693 path[ppos].p_hdr = eh;
694 i--;
695
Aneesh Kumar K.V7a262f72009-03-27 16:39:58 -0400696 if (need_to_validate && ext4_ext_check(inode, eh, i))
Alex Tomasa86c6182006-10-11 01:21:03 -0700697 goto err;
698 }
699
700 path[ppos].p_depth = i;
Alex Tomasa86c6182006-10-11 01:21:03 -0700701 path[ppos].p_ext = NULL;
702 path[ppos].p_idx = NULL;
703
Alex Tomasa86c6182006-10-11 01:21:03 -0700704 /* find extent */
705 ext4_ext_binsearch(inode, path + ppos, block);
Shen Feng1973adc2008-07-11 19:27:31 -0400706 /* if not an empty leaf */
707 if (path[ppos].p_ext)
708 path[ppos].p_block = ext_pblock(path[ppos].p_ext);
Alex Tomasa86c6182006-10-11 01:21:03 -0700709
710 ext4_ext_show_path(inode, path);
711
712 return path;
713
714err:
715 ext4_ext_drop_refs(path);
716 if (alloc)
717 kfree(path);
718 return ERR_PTR(-EIO);
719}
720
721/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700722 * ext4_ext_insert_index:
723 * insert new index [@logical;@ptr] into the block at @curp;
724 * check where to insert: before @curp or after @curp
Alex Tomasa86c6182006-10-11 01:21:03 -0700725 */
Mingming Cao00314622009-09-28 15:49:08 -0400726int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -0700727 struct ext4_ext_path *curp,
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700728 int logical, ext4_fsblk_t ptr)
Alex Tomasa86c6182006-10-11 01:21:03 -0700729{
730 struct ext4_extent_idx *ix;
731 int len, err;
732
Avantika Mathur7e028972006-12-06 20:41:33 -0800733 err = ext4_ext_get_access(handle, inode, curp);
734 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700735 return err;
736
737 BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block));
738 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
739 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
740 /* insert after */
741 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
742 len = (len - 1) * sizeof(struct ext4_extent_idx);
743 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400744 ext_debug("insert new index %d after: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700745 "move %d from 0x%p to 0x%p\n",
746 logical, ptr, len,
747 (curp->p_idx + 1), (curp->p_idx + 2));
748 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
749 }
750 ix = curp->p_idx + 1;
751 } else {
752 /* insert before */
753 len = len * sizeof(struct ext4_extent_idx);
754 len = len < 0 ? 0 : len;
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400755 ext_debug("insert new index %d before: %llu. "
Alex Tomasa86c6182006-10-11 01:21:03 -0700756 "move %d from 0x%p to 0x%p\n",
757 logical, ptr, len,
758 curp->p_idx, (curp->p_idx + 1));
759 memmove(curp->p_idx + 1, curp->p_idx, len);
760 ix = curp->p_idx;
761 }
762
763 ix->ei_block = cpu_to_le32(logical);
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700764 ext4_idx_store_pblock(ix, ptr);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400765 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -0700766
767 BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries)
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400768 > le16_to_cpu(curp->p_hdr->eh_max));
Alex Tomasa86c6182006-10-11 01:21:03 -0700769 BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr));
770
771 err = ext4_ext_dirty(handle, inode, curp);
772 ext4_std_error(inode->i_sb, err);
773
774 return err;
775}
776
777/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700778 * ext4_ext_split:
779 * inserts new subtree into the path, using free index entry
780 * at depth @at:
781 * - allocates all needed blocks (new leaf and all intermediate index blocks)
782 * - makes decision where to split
783 * - moves remaining extents and index entries (right to the split point)
784 * into the newly allocated blocks
785 * - initializes subtree
Alex Tomasa86c6182006-10-11 01:21:03 -0700786 */
787static int ext4_ext_split(handle_t *handle, struct inode *inode,
788 struct ext4_ext_path *path,
789 struct ext4_extent *newext, int at)
790{
791 struct buffer_head *bh = NULL;
792 int depth = ext_depth(inode);
793 struct ext4_extent_header *neh;
794 struct ext4_extent_idx *fidx;
795 struct ext4_extent *ex;
796 int i = at, k, m, a;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700797 ext4_fsblk_t newblock, oldblock;
Alex Tomasa86c6182006-10-11 01:21:03 -0700798 __le32 border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700799 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
Alex Tomasa86c6182006-10-11 01:21:03 -0700800 int err = 0;
801
802 /* make decision: where to split? */
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700803 /* FIXME: now decision is simplest: at current extent */
Alex Tomasa86c6182006-10-11 01:21:03 -0700804
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700805 /* if current leaf will be split, then we should use
Alex Tomasa86c6182006-10-11 01:21:03 -0700806 * border from split point */
807 BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr));
808 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
809 border = path[depth].p_ext[1].ee_block;
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700810 ext_debug("leaf will be split."
Alex Tomasa86c6182006-10-11 01:21:03 -0700811 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400812 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700813 } else {
814 border = newext->ee_block;
815 ext_debug("leaf will be added."
816 " next leaf starts at %d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400817 le32_to_cpu(border));
Alex Tomasa86c6182006-10-11 01:21:03 -0700818 }
819
820 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700821 * If error occurs, then we break processing
822 * and mark filesystem read-only. index won't
Alex Tomasa86c6182006-10-11 01:21:03 -0700823 * be inserted and tree will be in consistent
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700824 * state. Next mount will repair buffers too.
Alex Tomasa86c6182006-10-11 01:21:03 -0700825 */
826
827 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700828 * Get array to track all allocated blocks.
829 * We need this to handle errors and free blocks
830 * upon them.
Alex Tomasa86c6182006-10-11 01:21:03 -0700831 */
Avantika Mathur5d4958f2006-12-06 20:41:35 -0800832 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -0700833 if (!ablocks)
834 return -ENOMEM;
Alex Tomasa86c6182006-10-11 01:21:03 -0700835
836 /* allocate all needed blocks */
837 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
838 for (a = 0; a < depth - at; a++) {
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -0400839 newblock = ext4_ext_new_meta_block(handle, inode, path,
840 newext, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -0700841 if (newblock == 0)
842 goto cleanup;
843 ablocks[a] = newblock;
844 }
845
846 /* initialize new leaf */
847 newblock = ablocks[--a];
848 BUG_ON(newblock == 0);
849 bh = sb_getblk(inode->i_sb, newblock);
850 if (!bh) {
851 err = -EIO;
852 goto cleanup;
853 }
854 lock_buffer(bh);
855
Avantika Mathur7e028972006-12-06 20:41:33 -0800856 err = ext4_journal_get_create_access(handle, bh);
857 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700858 goto cleanup;
859
860 neh = ext_block_hdr(bh);
861 neh->eh_entries = 0;
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400862 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -0700863 neh->eh_magic = EXT4_EXT_MAGIC;
864 neh->eh_depth = 0;
865 ex = EXT_FIRST_EXTENT(neh);
866
Randy Dunlapd0d856e2006-10-11 01:21:07 -0700867 /* move remainder of path[depth] to the new leaf */
Alex Tomasa86c6182006-10-11 01:21:03 -0700868 BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max);
869 /* start copy from next extent */
870 /* TODO: we could do it by single memmove */
871 m = 0;
872 path[depth].p_ext++;
873 while (path[depth].p_ext <=
874 EXT_MAX_EXTENT(path[depth].p_hdr)) {
Mingming553f9002009-09-18 13:34:55 -0400875 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400876 le32_to_cpu(path[depth].p_ext->ee_block),
877 ext_pblock(path[depth].p_ext),
Mingming553f9002009-09-18 13:34:55 -0400878 ext4_ext_is_uninitialized(path[depth].p_ext),
Amit Aroraa2df2a62007-07-17 21:42:41 -0400879 ext4_ext_get_actual_len(path[depth].p_ext),
Alex Tomasa86c6182006-10-11 01:21:03 -0700880 newblock);
881 /*memmove(ex++, path[depth].p_ext++,
882 sizeof(struct ext4_extent));
883 neh->eh_entries++;*/
884 path[depth].p_ext++;
885 m++;
886 }
887 if (m) {
888 memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400889 le16_add_cpu(&neh->eh_entries, m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700890 }
891
892 set_buffer_uptodate(bh);
893 unlock_buffer(bh);
894
Frank Mayhar03901312009-01-07 00:06:22 -0500895 err = ext4_handle_dirty_metadata(handle, inode, bh);
Avantika Mathur7e028972006-12-06 20:41:33 -0800896 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700897 goto cleanup;
898 brelse(bh);
899 bh = NULL;
900
901 /* correct old leaf */
902 if (m) {
Avantika Mathur7e028972006-12-06 20:41:33 -0800903 err = ext4_ext_get_access(handle, inode, path + depth);
904 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700905 goto cleanup;
Marcin Slusarze8546d02008-04-17 10:38:59 -0400906 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
Avantika Mathur7e028972006-12-06 20:41:33 -0800907 err = ext4_ext_dirty(handle, inode, path + depth);
908 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700909 goto cleanup;
910
911 }
912
913 /* create intermediate indexes */
914 k = depth - at - 1;
915 BUG_ON(k < 0);
916 if (k)
917 ext_debug("create %d intermediate indices\n", k);
918 /* insert new index into current index block */
919 /* current depth stored in i var */
920 i = depth - 1;
921 while (k--) {
922 oldblock = newblock;
923 newblock = ablocks[--a];
Eric Sandeenbba90742008-01-28 23:58:27 -0500924 bh = sb_getblk(inode->i_sb, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700925 if (!bh) {
926 err = -EIO;
927 goto cleanup;
928 }
929 lock_buffer(bh);
930
Avantika Mathur7e028972006-12-06 20:41:33 -0800931 err = ext4_journal_get_create_access(handle, bh);
932 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700933 goto cleanup;
934
935 neh = ext_block_hdr(bh);
936 neh->eh_entries = cpu_to_le16(1);
937 neh->eh_magic = EXT4_EXT_MAGIC;
Theodore Ts'o55ad63b2009-08-28 10:40:33 -0400938 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -0700939 neh->eh_depth = cpu_to_le16(depth - i);
940 fidx = EXT_FIRST_INDEX(neh);
941 fidx->ei_block = border;
Alex Tomasf65e6fb2006-10-11 01:21:05 -0700942 ext4_idx_store_pblock(fidx, oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700943
Eric Sandeenbba90742008-01-28 23:58:27 -0500944 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
945 i, newblock, le32_to_cpu(border), oldblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700946 /* copy indexes */
947 m = 0;
948 path[i].p_idx++;
949
950 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
951 EXT_MAX_INDEX(path[i].p_hdr));
952 BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) !=
953 EXT_LAST_INDEX(path[i].p_hdr));
954 while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
Dmitry Monakhov26d535e2007-07-18 08:33:37 -0400955 ext_debug("%d: move %d:%llu in new index %llu\n", i,
Dave Kleikamp8c55e202007-05-24 13:04:54 -0400956 le32_to_cpu(path[i].p_idx->ei_block),
957 idx_pblock(path[i].p_idx),
958 newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -0700959 /*memmove(++fidx, path[i].p_idx++,
960 sizeof(struct ext4_extent_idx));
961 neh->eh_entries++;
962 BUG_ON(neh->eh_entries > neh->eh_max);*/
963 path[i].p_idx++;
964 m++;
965 }
966 if (m) {
967 memmove(++fidx, path[i].p_idx - m,
968 sizeof(struct ext4_extent_idx) * m);
Marcin Slusarze8546d02008-04-17 10:38:59 -0400969 le16_add_cpu(&neh->eh_entries, m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700970 }
971 set_buffer_uptodate(bh);
972 unlock_buffer(bh);
973
Frank Mayhar03901312009-01-07 00:06:22 -0500974 err = ext4_handle_dirty_metadata(handle, inode, bh);
Avantika Mathur7e028972006-12-06 20:41:33 -0800975 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -0700976 goto cleanup;
977 brelse(bh);
978 bh = NULL;
979
980 /* correct old index */
981 if (m) {
982 err = ext4_ext_get_access(handle, inode, path + i);
983 if (err)
984 goto cleanup;
Marcin Slusarze8546d02008-04-17 10:38:59 -0400985 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
Alex Tomasa86c6182006-10-11 01:21:03 -0700986 err = ext4_ext_dirty(handle, inode, path + i);
987 if (err)
988 goto cleanup;
989 }
990
991 i--;
992 }
993
994 /* insert new index */
Alex Tomasa86c6182006-10-11 01:21:03 -0700995 err = ext4_ext_insert_index(handle, inode, path + at,
996 le32_to_cpu(border), newblock);
997
998cleanup:
999 if (bh) {
1000 if (buffer_locked(bh))
1001 unlock_buffer(bh);
1002 brelse(bh);
1003 }
1004
1005 if (err) {
1006 /* free all allocated blocks in error case */
1007 for (i = 0; i < depth; i++) {
1008 if (!ablocks[i])
1009 continue;
Alex Tomasc9de5602008-01-29 00:19:52 -05001010 ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001011 }
1012 }
1013 kfree(ablocks);
1014
1015 return err;
1016}
1017
1018/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001019 * ext4_ext_grow_indepth:
1020 * implements tree growing procedure:
1021 * - allocates new block
1022 * - moves top-level data (index block or leaf) into the new block
1023 * - initializes new top-level, creating index that points to the
1024 * just created block
Alex Tomasa86c6182006-10-11 01:21:03 -07001025 */
1026static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1027 struct ext4_ext_path *path,
1028 struct ext4_extent *newext)
1029{
1030 struct ext4_ext_path *curp = path;
1031 struct ext4_extent_header *neh;
1032 struct ext4_extent_idx *fidx;
1033 struct buffer_head *bh;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001034 ext4_fsblk_t newblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001035 int err = 0;
1036
Aneesh Kumar K.V654b4902008-07-11 19:27:31 -04001037 newblock = ext4_ext_new_meta_block(handle, inode, path, newext, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -07001038 if (newblock == 0)
1039 return err;
1040
1041 bh = sb_getblk(inode->i_sb, newblock);
1042 if (!bh) {
1043 err = -EIO;
1044 ext4_std_error(inode->i_sb, err);
1045 return err;
1046 }
1047 lock_buffer(bh);
1048
Avantika Mathur7e028972006-12-06 20:41:33 -08001049 err = ext4_journal_get_create_access(handle, bh);
1050 if (err) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001051 unlock_buffer(bh);
1052 goto out;
1053 }
1054
1055 /* move top-level index/leaf into new block */
1056 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
1057
1058 /* set size of new block */
1059 neh = ext_block_hdr(bh);
1060 /* old root could have indexes or leaves
1061 * so calculate e_max right way */
1062 if (ext_depth(inode))
Theodore Ts'o55ad63b2009-08-28 10:40:33 -04001063 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -07001064 else
Theodore Ts'o55ad63b2009-08-28 10:40:33 -04001065 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -07001066 neh->eh_magic = EXT4_EXT_MAGIC;
1067 set_buffer_uptodate(bh);
1068 unlock_buffer(bh);
1069
Frank Mayhar03901312009-01-07 00:06:22 -05001070 err = ext4_handle_dirty_metadata(handle, inode, bh);
Avantika Mathur7e028972006-12-06 20:41:33 -08001071 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001072 goto out;
1073
1074 /* create index in new top-level index: num,max,pointer */
Avantika Mathur7e028972006-12-06 20:41:33 -08001075 err = ext4_ext_get_access(handle, inode, curp);
1076 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001077 goto out;
1078
1079 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
Theodore Ts'o55ad63b2009-08-28 10:40:33 -04001080 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -07001081 curp->p_hdr->eh_entries = cpu_to_le16(1);
1082 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
Dmitry Monakhove9f410b2007-07-18 09:09:15 -04001083
1084 if (path[0].p_hdr->eh_depth)
1085 curp->p_idx->ei_block =
1086 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
1087 else
1088 curp->p_idx->ei_block =
1089 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001090 ext4_idx_store_pblock(curp->p_idx, newblock);
Alex Tomasa86c6182006-10-11 01:21:03 -07001091
1092 neh = ext_inode_hdr(inode);
1093 fidx = EXT_FIRST_INDEX(neh);
Mingming Cao2ae02102006-10-11 01:21:11 -07001094 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
Alex Tomasa86c6182006-10-11 01:21:03 -07001095 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001096 le32_to_cpu(fidx->ei_block), idx_pblock(fidx));
Alex Tomasa86c6182006-10-11 01:21:03 -07001097
1098 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
1099 err = ext4_ext_dirty(handle, inode, curp);
1100out:
1101 brelse(bh);
1102
1103 return err;
1104}
1105
1106/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001107 * ext4_ext_create_new_leaf:
1108 * finds empty index and adds new leaf.
1109 * if no free index is found, then it requests in-depth growing.
Alex Tomasa86c6182006-10-11 01:21:03 -07001110 */
1111static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1112 struct ext4_ext_path *path,
1113 struct ext4_extent *newext)
1114{
1115 struct ext4_ext_path *curp;
1116 int depth, i, err = 0;
1117
1118repeat:
1119 i = depth = ext_depth(inode);
1120
1121 /* walk up to the tree and look for free index entry */
1122 curp = path + depth;
1123 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1124 i--;
1125 curp--;
1126 }
1127
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001128 /* we use already allocated block for index block,
1129 * so subsequent data blocks should be contiguous */
Alex Tomasa86c6182006-10-11 01:21:03 -07001130 if (EXT_HAS_FREE_INDEX(curp)) {
1131 /* if we found index with free entry, then use that
1132 * entry: create all needed subtree and add new leaf */
1133 err = ext4_ext_split(handle, inode, path, newext, i);
Shen Feng787e0982008-07-11 19:27:31 -04001134 if (err)
1135 goto out;
Alex Tomasa86c6182006-10-11 01:21:03 -07001136
1137 /* refill path */
1138 ext4_ext_drop_refs(path);
1139 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001140 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1141 path);
Alex Tomasa86c6182006-10-11 01:21:03 -07001142 if (IS_ERR(path))
1143 err = PTR_ERR(path);
1144 } else {
1145 /* tree is full, time to grow in depth */
1146 err = ext4_ext_grow_indepth(handle, inode, path, newext);
1147 if (err)
1148 goto out;
1149
1150 /* refill path */
1151 ext4_ext_drop_refs(path);
1152 path = ext4_ext_find_extent(inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001153 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1154 path);
Alex Tomasa86c6182006-10-11 01:21:03 -07001155 if (IS_ERR(path)) {
1156 err = PTR_ERR(path);
1157 goto out;
1158 }
1159
1160 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001161 * only first (depth 0 -> 1) produces free space;
1162 * in all other cases we have to split the grown tree
Alex Tomasa86c6182006-10-11 01:21:03 -07001163 */
1164 depth = ext_depth(inode);
1165 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001166 /* now we need to split */
Alex Tomasa86c6182006-10-11 01:21:03 -07001167 goto repeat;
1168 }
1169 }
1170
1171out:
1172 return err;
1173}
1174
1175/*
Alex Tomas1988b512008-01-28 23:58:27 -05001176 * search the closest allocated block to the left for *logical
1177 * and returns it at @logical + it's physical address at @phys
1178 * if *logical is the smallest allocated block, the function
1179 * returns 0 at @phys
1180 * return value contains 0 (success) or error code
1181 */
1182int
1183ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
1184 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1185{
1186 struct ext4_extent_idx *ix;
1187 struct ext4_extent *ex;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001188 int depth, ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001189
1190 BUG_ON(path == NULL);
1191 depth = path->p_depth;
1192 *phys = 0;
1193
1194 if (depth == 0 && path->p_ext == NULL)
1195 return 0;
1196
1197 /* usually extent in the path covers blocks smaller
1198 * then *logical, but it can be that extent is the
1199 * first one in the file */
1200
1201 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001202 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001203 if (*logical < le32_to_cpu(ex->ee_block)) {
1204 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1205 while (--depth >= 0) {
1206 ix = path[depth].p_idx;
1207 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1208 }
1209 return 0;
1210 }
1211
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001212 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001213
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001214 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1215 *phys = ext_pblock(ex) + ee_len - 1;
Alex Tomas1988b512008-01-28 23:58:27 -05001216 return 0;
1217}
1218
1219/*
1220 * search the closest allocated block to the right for *logical
1221 * and returns it at @logical + it's physical address at @phys
1222 * if *logical is the smallest allocated block, the function
1223 * returns 0 at @phys
1224 * return value contains 0 (success) or error code
1225 */
1226int
1227ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
1228 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1229{
1230 struct buffer_head *bh = NULL;
1231 struct ext4_extent_header *eh;
1232 struct ext4_extent_idx *ix;
1233 struct ext4_extent *ex;
1234 ext4_fsblk_t block;
Eric Sandeen395a87b2009-03-10 18:18:47 -04001235 int depth; /* Note, NOT eh_depth; depth from top of tree */
1236 int ee_len;
Alex Tomas1988b512008-01-28 23:58:27 -05001237
1238 BUG_ON(path == NULL);
1239 depth = path->p_depth;
1240 *phys = 0;
1241
1242 if (depth == 0 && path->p_ext == NULL)
1243 return 0;
1244
1245 /* usually extent in the path covers blocks smaller
1246 * then *logical, but it can be that extent is the
1247 * first one in the file */
1248
1249 ex = path[depth].p_ext;
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001250 ee_len = ext4_ext_get_actual_len(ex);
Alex Tomas1988b512008-01-28 23:58:27 -05001251 if (*logical < le32_to_cpu(ex->ee_block)) {
1252 BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
1253 while (--depth >= 0) {
1254 ix = path[depth].p_idx;
1255 BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
1256 }
1257 *logical = le32_to_cpu(ex->ee_block);
1258 *phys = ext_pblock(ex);
1259 return 0;
1260 }
1261
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001262 BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
Alex Tomas1988b512008-01-28 23:58:27 -05001263
1264 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1265 /* next allocated block in this leaf */
1266 ex++;
1267 *logical = le32_to_cpu(ex->ee_block);
1268 *phys = ext_pblock(ex);
1269 return 0;
1270 }
1271
1272 /* go up and search for index to the right */
1273 while (--depth >= 0) {
1274 ix = path[depth].p_idx;
1275 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
Wu Fengguang25f1ee32008-11-25 17:24:23 -05001276 goto got_index;
Alex Tomas1988b512008-01-28 23:58:27 -05001277 }
1278
Wu Fengguang25f1ee32008-11-25 17:24:23 -05001279 /* we've gone up to the root and found no index to the right */
1280 return 0;
Alex Tomas1988b512008-01-28 23:58:27 -05001281
Wu Fengguang25f1ee32008-11-25 17:24:23 -05001282got_index:
Alex Tomas1988b512008-01-28 23:58:27 -05001283 /* we've found index to the right, let's
1284 * follow it and find the closest allocated
1285 * block to the right */
1286 ix++;
1287 block = idx_pblock(ix);
1288 while (++depth < path->p_depth) {
1289 bh = sb_bread(inode->i_sb, block);
1290 if (bh == NULL)
1291 return -EIO;
1292 eh = ext_block_hdr(bh);
Eric Sandeen395a87b2009-03-10 18:18:47 -04001293 /* subtract from p_depth to get proper eh_depth */
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -04001294 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
Alex Tomas1988b512008-01-28 23:58:27 -05001295 put_bh(bh);
1296 return -EIO;
1297 }
1298 ix = EXT_FIRST_INDEX(eh);
1299 block = idx_pblock(ix);
1300 put_bh(bh);
1301 }
1302
1303 bh = sb_bread(inode->i_sb, block);
1304 if (bh == NULL)
1305 return -EIO;
1306 eh = ext_block_hdr(bh);
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -04001307 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
Alex Tomas1988b512008-01-28 23:58:27 -05001308 put_bh(bh);
1309 return -EIO;
1310 }
1311 ex = EXT_FIRST_EXTENT(eh);
1312 *logical = le32_to_cpu(ex->ee_block);
1313 *phys = ext_pblock(ex);
1314 put_bh(bh);
1315 return 0;
Alex Tomas1988b512008-01-28 23:58:27 -05001316}
1317
1318/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001319 * ext4_ext_next_allocated_block:
1320 * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
1321 * NOTE: it considers block number from index entry as
1322 * allocated block. Thus, index entries have to be consistent
1323 * with leaves.
Alex Tomasa86c6182006-10-11 01:21:03 -07001324 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001325static ext4_lblk_t
Alex Tomasa86c6182006-10-11 01:21:03 -07001326ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1327{
1328 int depth;
1329
1330 BUG_ON(path == NULL);
1331 depth = path->p_depth;
1332
1333 if (depth == 0 && path->p_ext == NULL)
1334 return EXT_MAX_BLOCK;
1335
1336 while (depth >= 0) {
1337 if (depth == path->p_depth) {
1338 /* leaf */
1339 if (path[depth].p_ext !=
1340 EXT_LAST_EXTENT(path[depth].p_hdr))
1341 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1342 } else {
1343 /* index */
1344 if (path[depth].p_idx !=
1345 EXT_LAST_INDEX(path[depth].p_hdr))
1346 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1347 }
1348 depth--;
1349 }
1350
1351 return EXT_MAX_BLOCK;
1352}
1353
1354/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001355 * ext4_ext_next_leaf_block:
Alex Tomasa86c6182006-10-11 01:21:03 -07001356 * returns first allocated block from next leaf or EXT_MAX_BLOCK
1357 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001358static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
Andrew Morton63f57932006-10-11 01:21:24 -07001359 struct ext4_ext_path *path)
Alex Tomasa86c6182006-10-11 01:21:03 -07001360{
1361 int depth;
1362
1363 BUG_ON(path == NULL);
1364 depth = path->p_depth;
1365
1366 /* zero-tree has no leaf blocks at all */
1367 if (depth == 0)
1368 return EXT_MAX_BLOCK;
1369
1370 /* go to index block */
1371 depth--;
1372
1373 while (depth >= 0) {
1374 if (path[depth].p_idx !=
1375 EXT_LAST_INDEX(path[depth].p_hdr))
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001376 return (ext4_lblk_t)
1377 le32_to_cpu(path[depth].p_idx[1].ei_block);
Alex Tomasa86c6182006-10-11 01:21:03 -07001378 depth--;
1379 }
1380
1381 return EXT_MAX_BLOCK;
1382}
1383
1384/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001385 * ext4_ext_correct_indexes:
1386 * if leaf gets modified and modified extent is first in the leaf,
1387 * then we have to correct all indexes above.
Alex Tomasa86c6182006-10-11 01:21:03 -07001388 * TODO: do we need to correct tree in all cases?
1389 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001390static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001391 struct ext4_ext_path *path)
1392{
1393 struct ext4_extent_header *eh;
1394 int depth = ext_depth(inode);
1395 struct ext4_extent *ex;
1396 __le32 border;
1397 int k, err = 0;
1398
1399 eh = path[depth].p_hdr;
1400 ex = path[depth].p_ext;
1401 BUG_ON(ex == NULL);
1402 BUG_ON(eh == NULL);
1403
1404 if (depth == 0) {
1405 /* there is no tree at all */
1406 return 0;
1407 }
1408
1409 if (ex != EXT_FIRST_EXTENT(eh)) {
1410 /* we correct tree if first leaf got modified only */
1411 return 0;
1412 }
1413
1414 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001415 * TODO: we need correction if border is smaller than current one
Alex Tomasa86c6182006-10-11 01:21:03 -07001416 */
1417 k = depth - 1;
1418 border = path[depth].p_ext->ee_block;
Avantika Mathur7e028972006-12-06 20:41:33 -08001419 err = ext4_ext_get_access(handle, inode, path + k);
1420 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001421 return err;
1422 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001423 err = ext4_ext_dirty(handle, inode, path + k);
1424 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001425 return err;
1426
1427 while (k--) {
1428 /* change all left-side indexes */
1429 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1430 break;
Avantika Mathur7e028972006-12-06 20:41:33 -08001431 err = ext4_ext_get_access(handle, inode, path + k);
1432 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001433 break;
1434 path[k].p_idx->ei_block = border;
Avantika Mathur7e028972006-12-06 20:41:33 -08001435 err = ext4_ext_dirty(handle, inode, path + k);
1436 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001437 break;
1438 }
1439
1440 return err;
1441}
1442
Akira Fujita748de672009-06-17 19:24:03 -04001443int
Alex Tomasa86c6182006-10-11 01:21:03 -07001444ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1445 struct ext4_extent *ex2)
1446{
Amit Arora749269f2007-07-18 09:02:56 -04001447 unsigned short ext1_ee_len, ext2_ee_len, max_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001448
1449 /*
1450 * Make sure that either both extents are uninitialized, or
1451 * both are _not_.
1452 */
1453 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1454 return 0;
1455
Amit Arora749269f2007-07-18 09:02:56 -04001456 if (ext4_ext_is_uninitialized(ex1))
1457 max_len = EXT_UNINIT_MAX_LEN;
1458 else
1459 max_len = EXT_INIT_MAX_LEN;
1460
Amit Aroraa2df2a62007-07-17 21:42:41 -04001461 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1462 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1463
1464 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
Andrew Morton63f57932006-10-11 01:21:24 -07001465 le32_to_cpu(ex2->ee_block))
Alex Tomasa86c6182006-10-11 01:21:03 -07001466 return 0;
1467
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001468 /*
1469 * To allow future support for preallocated extents to be added
1470 * as an RO_COMPAT feature, refuse to merge to extents if
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001471 * this can result in the top bit of ee_len being set.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001472 */
Amit Arora749269f2007-07-18 09:02:56 -04001473 if (ext1_ee_len + ext2_ee_len > max_len)
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07001474 return 0;
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01001475#ifdef AGGRESSIVE_TEST
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05001476 if (ext1_ee_len >= 4)
Alex Tomasa86c6182006-10-11 01:21:03 -07001477 return 0;
1478#endif
1479
Amit Aroraa2df2a62007-07-17 21:42:41 -04001480 if (ext_pblock(ex1) + ext1_ee_len == ext_pblock(ex2))
Alex Tomasa86c6182006-10-11 01:21:03 -07001481 return 1;
1482 return 0;
1483}
1484
1485/*
Amit Arora56055d32007-07-17 21:42:38 -04001486 * This function tries to merge the "ex" extent to the next extent in the tree.
1487 * It always tries to merge towards right. If you want to merge towards
1488 * left, pass "ex - 1" as argument instead of "ex".
1489 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1490 * 1 if they got merged.
1491 */
1492int ext4_ext_try_to_merge(struct inode *inode,
1493 struct ext4_ext_path *path,
1494 struct ext4_extent *ex)
1495{
1496 struct ext4_extent_header *eh;
1497 unsigned int depth, len;
1498 int merge_done = 0;
1499 int uninitialized = 0;
1500
1501 depth = ext_depth(inode);
1502 BUG_ON(path[depth].p_hdr == NULL);
1503 eh = path[depth].p_hdr;
1504
1505 while (ex < EXT_LAST_EXTENT(eh)) {
1506 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1507 break;
1508 /* merge with next extent! */
1509 if (ext4_ext_is_uninitialized(ex))
1510 uninitialized = 1;
1511 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1512 + ext4_ext_get_actual_len(ex + 1));
1513 if (uninitialized)
1514 ext4_ext_mark_uninitialized(ex);
1515
1516 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1517 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1518 * sizeof(struct ext4_extent);
1519 memmove(ex + 1, ex + 2, len);
1520 }
Marcin Slusarze8546d02008-04-17 10:38:59 -04001521 le16_add_cpu(&eh->eh_entries, -1);
Amit Arora56055d32007-07-17 21:42:38 -04001522 merge_done = 1;
1523 WARN_ON(eh->eh_entries == 0);
1524 if (!eh->eh_entries)
1525 ext4_error(inode->i_sb, "ext4_ext_try_to_merge",
1526 "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
1527 }
1528
1529 return merge_done;
1530}
1531
1532/*
Amit Arora25d14f92007-05-24 13:04:13 -04001533 * check if a portion of the "newext" extent overlaps with an
1534 * existing extent.
1535 *
1536 * If there is an overlap discovered, it updates the length of the newext
1537 * such that there will be no overlap, and then returns 1.
1538 * If there is no overlap found, it returns 0.
1539 */
1540unsigned int ext4_ext_check_overlap(struct inode *inode,
1541 struct ext4_extent *newext,
1542 struct ext4_ext_path *path)
1543{
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001544 ext4_lblk_t b1, b2;
Amit Arora25d14f92007-05-24 13:04:13 -04001545 unsigned int depth, len1;
1546 unsigned int ret = 0;
1547
1548 b1 = le32_to_cpu(newext->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04001549 len1 = ext4_ext_get_actual_len(newext);
Amit Arora25d14f92007-05-24 13:04:13 -04001550 depth = ext_depth(inode);
1551 if (!path[depth].p_ext)
1552 goto out;
1553 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1554
1555 /*
1556 * get the next allocated block if the extent in the path
Theodore Ts'o2b2d6d02008-07-26 16:15:44 -04001557 * is before the requested block(s)
Amit Arora25d14f92007-05-24 13:04:13 -04001558 */
1559 if (b2 < b1) {
1560 b2 = ext4_ext_next_allocated_block(path);
1561 if (b2 == EXT_MAX_BLOCK)
1562 goto out;
1563 }
1564
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001565 /* check for wrap through zero on extent logical start block*/
Amit Arora25d14f92007-05-24 13:04:13 -04001566 if (b1 + len1 < b1) {
1567 len1 = EXT_MAX_BLOCK - b1;
1568 newext->ee_len = cpu_to_le16(len1);
1569 ret = 1;
1570 }
1571
1572 /* check for overlap */
1573 if (b1 + len1 > b2) {
1574 newext->ee_len = cpu_to_le16(b2 - b1);
1575 ret = 1;
1576 }
1577out:
1578 return ret;
1579}
1580
1581/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001582 * ext4_ext_insert_extent:
1583 * tries to merge requsted extent into the existing extent or
1584 * inserts requested extent as new one into the tree,
1585 * creating new leaf in the no-space case.
Alex Tomasa86c6182006-10-11 01:21:03 -07001586 */
1587int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1588 struct ext4_ext_path *path,
Mingming Cao00314622009-09-28 15:49:08 -04001589 struct ext4_extent *newext, int flag)
Alex Tomasa86c6182006-10-11 01:21:03 -07001590{
Theodore Ts'oaf5bc922008-09-08 22:25:24 -04001591 struct ext4_extent_header *eh;
Alex Tomasa86c6182006-10-11 01:21:03 -07001592 struct ext4_extent *ex, *fex;
1593 struct ext4_extent *nearex; /* nearest extent */
1594 struct ext4_ext_path *npath = NULL;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001595 int depth, len, err;
1596 ext4_lblk_t next;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001597 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07001598
Amit Aroraa2df2a62007-07-17 21:42:41 -04001599 BUG_ON(ext4_ext_get_actual_len(newext) == 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07001600 depth = ext_depth(inode);
1601 ex = path[depth].p_ext;
1602 BUG_ON(path[depth].p_hdr == NULL);
1603
1604 /* try to insert block into found extent and return */
Mingming Cao00314622009-09-28 15:49:08 -04001605 if (ex && (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT)
1606 && ext4_can_extents_be_merged(inode, ex, newext)) {
Mingming553f9002009-09-18 13:34:55 -04001607 ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
1608 ext4_ext_is_uninitialized(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001609 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001610 le32_to_cpu(ex->ee_block),
Mingming553f9002009-09-18 13:34:55 -04001611 ext4_ext_is_uninitialized(ex),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001612 ext4_ext_get_actual_len(ex), ext_pblock(ex));
Avantika Mathur7e028972006-12-06 20:41:33 -08001613 err = ext4_ext_get_access(handle, inode, path + depth);
1614 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001615 return err;
Amit Aroraa2df2a62007-07-17 21:42:41 -04001616
1617 /*
1618 * ext4_can_extents_be_merged should have checked that either
1619 * both extents are uninitialized, or both aren't. Thus we
1620 * need to check only one of them here.
1621 */
1622 if (ext4_ext_is_uninitialized(ex))
1623 uninitialized = 1;
1624 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1625 + ext4_ext_get_actual_len(newext));
1626 if (uninitialized)
1627 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001628 eh = path[depth].p_hdr;
1629 nearex = ex;
1630 goto merge;
1631 }
1632
1633repeat:
1634 depth = ext_depth(inode);
1635 eh = path[depth].p_hdr;
1636 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1637 goto has_space;
1638
1639 /* probably next leaf has space for us? */
1640 fex = EXT_LAST_EXTENT(eh);
1641 next = ext4_ext_next_leaf_block(inode, path);
1642 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
1643 && next != EXT_MAX_BLOCK) {
1644 ext_debug("next leaf block - %d\n", next);
1645 BUG_ON(npath != NULL);
1646 npath = ext4_ext_find_extent(inode, next, NULL);
1647 if (IS_ERR(npath))
1648 return PTR_ERR(npath);
1649 BUG_ON(npath->p_depth != path->p_depth);
1650 eh = npath[depth].p_hdr;
1651 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1652 ext_debug("next leaf isnt full(%d)\n",
1653 le16_to_cpu(eh->eh_entries));
1654 path = npath;
1655 goto repeat;
1656 }
1657 ext_debug("next leaf has no free space(%d,%d)\n",
1658 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1659 }
1660
1661 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001662 * There is no free space in the found leaf.
1663 * We're gonna add a new leaf in the tree.
Alex Tomasa86c6182006-10-11 01:21:03 -07001664 */
1665 err = ext4_ext_create_new_leaf(handle, inode, path, newext);
1666 if (err)
1667 goto cleanup;
1668 depth = ext_depth(inode);
1669 eh = path[depth].p_hdr;
1670
1671has_space:
1672 nearex = path[depth].p_ext;
1673
Avantika Mathur7e028972006-12-06 20:41:33 -08001674 err = ext4_ext_get_access(handle, inode, path + depth);
1675 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001676 goto cleanup;
1677
1678 if (!nearex) {
1679 /* there is no extent in this leaf, create first one */
Mingming553f9002009-09-18 13:34:55 -04001680 ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001681 le32_to_cpu(newext->ee_block),
1682 ext_pblock(newext),
Mingming553f9002009-09-18 13:34:55 -04001683 ext4_ext_is_uninitialized(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001684 ext4_ext_get_actual_len(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001685 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1686 } else if (le32_to_cpu(newext->ee_block)
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001687 > le32_to_cpu(nearex->ee_block)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07001688/* BUG_ON(newext->ee_block == nearex->ee_block); */
1689 if (nearex != EXT_LAST_EXTENT(eh)) {
1690 len = EXT_MAX_EXTENT(eh) - nearex;
1691 len = (len - 1) * sizeof(struct ext4_extent);
1692 len = len < 0 ? 0 : len;
Mingming553f9002009-09-18 13:34:55 -04001693 ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001694 "move %d from 0x%p to 0x%p\n",
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001695 le32_to_cpu(newext->ee_block),
1696 ext_pblock(newext),
Mingming553f9002009-09-18 13:34:55 -04001697 ext4_ext_is_uninitialized(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001698 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001699 nearex, len, nearex + 1, nearex + 2);
1700 memmove(nearex + 2, nearex + 1, len);
1701 }
1702 path[depth].p_ext = nearex + 1;
1703 } else {
1704 BUG_ON(newext->ee_block == nearex->ee_block);
1705 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1706 len = len < 0 ? 0 : len;
Mingming553f9002009-09-18 13:34:55 -04001707 ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, "
Alex Tomasa86c6182006-10-11 01:21:03 -07001708 "move %d from 0x%p to 0x%p\n",
1709 le32_to_cpu(newext->ee_block),
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001710 ext_pblock(newext),
Mingming553f9002009-09-18 13:34:55 -04001711 ext4_ext_is_uninitialized(newext),
Amit Aroraa2df2a62007-07-17 21:42:41 -04001712 ext4_ext_get_actual_len(newext),
Alex Tomasa86c6182006-10-11 01:21:03 -07001713 nearex, len, nearex + 1, nearex + 2);
1714 memmove(nearex + 1, nearex, len);
1715 path[depth].p_ext = nearex;
1716 }
1717
Marcin Slusarze8546d02008-04-17 10:38:59 -04001718 le16_add_cpu(&eh->eh_entries, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001719 nearex = path[depth].p_ext;
1720 nearex->ee_block = newext->ee_block;
Aneesh Kumar K.Vb3776112007-10-16 18:38:25 -04001721 ext4_ext_store_pblock(nearex, ext_pblock(newext));
Alex Tomasa86c6182006-10-11 01:21:03 -07001722 nearex->ee_len = newext->ee_len;
Alex Tomasa86c6182006-10-11 01:21:03 -07001723
1724merge:
1725 /* try to merge extents to the right */
Mingming Cao00314622009-09-28 15:49:08 -04001726 if (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT)
1727 ext4_ext_try_to_merge(inode, path, nearex);
Alex Tomasa86c6182006-10-11 01:21:03 -07001728
1729 /* try to merge extents to the left */
1730
1731 /* time to correct all indexes above */
1732 err = ext4_ext_correct_indexes(handle, inode, path);
1733 if (err)
1734 goto cleanup;
1735
1736 err = ext4_ext_dirty(handle, inode, path + depth);
1737
1738cleanup:
1739 if (npath) {
1740 ext4_ext_drop_refs(npath);
1741 kfree(npath);
1742 }
Alex Tomasa86c6182006-10-11 01:21:03 -07001743 ext4_ext_invalidate_cache(inode);
1744 return err;
1745}
1746
Eric Sandeen6873fa02008-10-07 00:46:36 -04001747int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
1748 ext4_lblk_t num, ext_prepare_callback func,
1749 void *cbdata)
1750{
1751 struct ext4_ext_path *path = NULL;
1752 struct ext4_ext_cache cbex;
1753 struct ext4_extent *ex;
1754 ext4_lblk_t next, start = 0, end = 0;
1755 ext4_lblk_t last = block + num;
1756 int depth, exists, err = 0;
1757
1758 BUG_ON(func == NULL);
1759 BUG_ON(inode == NULL);
1760
1761 while (block < last && block != EXT_MAX_BLOCK) {
1762 num = last - block;
1763 /* find extent for this block */
1764 path = ext4_ext_find_extent(inode, block, path);
1765 if (IS_ERR(path)) {
1766 err = PTR_ERR(path);
1767 path = NULL;
1768 break;
1769 }
1770
1771 depth = ext_depth(inode);
1772 BUG_ON(path[depth].p_hdr == NULL);
1773 ex = path[depth].p_ext;
1774 next = ext4_ext_next_allocated_block(path);
1775
1776 exists = 0;
1777 if (!ex) {
1778 /* there is no extent yet, so try to allocate
1779 * all requested space */
1780 start = block;
1781 end = block + num;
1782 } else if (le32_to_cpu(ex->ee_block) > block) {
1783 /* need to allocate space before found extent */
1784 start = block;
1785 end = le32_to_cpu(ex->ee_block);
1786 if (block + num < end)
1787 end = block + num;
1788 } else if (block >= le32_to_cpu(ex->ee_block)
1789 + ext4_ext_get_actual_len(ex)) {
1790 /* need to allocate space after found extent */
1791 start = block;
1792 end = block + num;
1793 if (end >= next)
1794 end = next;
1795 } else if (block >= le32_to_cpu(ex->ee_block)) {
1796 /*
1797 * some part of requested space is covered
1798 * by found extent
1799 */
1800 start = block;
1801 end = le32_to_cpu(ex->ee_block)
1802 + ext4_ext_get_actual_len(ex);
1803 if (block + num < end)
1804 end = block + num;
1805 exists = 1;
1806 } else {
1807 BUG();
1808 }
1809 BUG_ON(end <= start);
1810
1811 if (!exists) {
1812 cbex.ec_block = start;
1813 cbex.ec_len = end - start;
1814 cbex.ec_start = 0;
1815 cbex.ec_type = EXT4_EXT_CACHE_GAP;
1816 } else {
1817 cbex.ec_block = le32_to_cpu(ex->ee_block);
1818 cbex.ec_len = ext4_ext_get_actual_len(ex);
1819 cbex.ec_start = ext_pblock(ex);
1820 cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
1821 }
1822
1823 BUG_ON(cbex.ec_len == 0);
1824 err = func(inode, path, &cbex, ex, cbdata);
1825 ext4_ext_drop_refs(path);
1826
1827 if (err < 0)
1828 break;
1829
1830 if (err == EXT_REPEAT)
1831 continue;
1832 else if (err == EXT_BREAK) {
1833 err = 0;
1834 break;
1835 }
1836
1837 if (ext_depth(inode) != depth) {
1838 /* depth was changed. we have to realloc path */
1839 kfree(path);
1840 path = NULL;
1841 }
1842
1843 block = cbex.ec_block + cbex.ec_len;
1844 }
1845
1846 if (path) {
1847 ext4_ext_drop_refs(path);
1848 kfree(path);
1849 }
1850
1851 return err;
1852}
1853
Avantika Mathur09b88252006-12-06 20:41:36 -08001854static void
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001855ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
Mingming Caodd545672007-07-31 00:37:46 -07001856 __u32 len, ext4_fsblk_t start, int type)
Alex Tomasa86c6182006-10-11 01:21:03 -07001857{
1858 struct ext4_ext_cache *cex;
1859 BUG_ON(len == 0);
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001860 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
Alex Tomasa86c6182006-10-11 01:21:03 -07001861 cex = &EXT4_I(inode)->i_cached_extent;
1862 cex->ec_type = type;
1863 cex->ec_block = block;
1864 cex->ec_len = len;
1865 cex->ec_start = start;
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001866 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
Alex Tomasa86c6182006-10-11 01:21:03 -07001867}
1868
1869/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001870 * ext4_ext_put_gap_in_cache:
1871 * calculate boundaries of the gap that the requested block fits into
Alex Tomasa86c6182006-10-11 01:21:03 -07001872 * and cache this gap
1873 */
Avantika Mathur09b88252006-12-06 20:41:36 -08001874static void
Alex Tomasa86c6182006-10-11 01:21:03 -07001875ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001876 ext4_lblk_t block)
Alex Tomasa86c6182006-10-11 01:21:03 -07001877{
1878 int depth = ext_depth(inode);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001879 unsigned long len;
1880 ext4_lblk_t lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001881 struct ext4_extent *ex;
1882
1883 ex = path[depth].p_ext;
1884 if (ex == NULL) {
1885 /* there is no extent yet, so gap is [0;-] */
1886 lblock = 0;
1887 len = EXT_MAX_BLOCK;
1888 ext_debug("cache gap(whole file):");
1889 } else if (block < le32_to_cpu(ex->ee_block)) {
1890 lblock = block;
1891 len = le32_to_cpu(ex->ee_block) - block;
Eric Sandeenbba90742008-01-28 23:58:27 -05001892 ext_debug("cache gap(before): %u [%u:%u]",
1893 block,
1894 le32_to_cpu(ex->ee_block),
1895 ext4_ext_get_actual_len(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07001896 } else if (block >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001897 + ext4_ext_get_actual_len(ex)) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001898 ext4_lblk_t next;
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001899 lblock = le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04001900 + ext4_ext_get_actual_len(ex);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001901
1902 next = ext4_ext_next_allocated_block(path);
Eric Sandeenbba90742008-01-28 23:58:27 -05001903 ext_debug("cache gap(after): [%u:%u] %u",
1904 le32_to_cpu(ex->ee_block),
1905 ext4_ext_get_actual_len(ex),
1906 block);
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001907 BUG_ON(next == lblock);
1908 len = next - lblock;
Alex Tomasa86c6182006-10-11 01:21:03 -07001909 } else {
1910 lblock = len = 0;
1911 BUG();
1912 }
1913
Eric Sandeenbba90742008-01-28 23:58:27 -05001914 ext_debug(" -> %u:%lu\n", lblock, len);
Alex Tomasa86c6182006-10-11 01:21:03 -07001915 ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
1916}
1917
Avantika Mathur09b88252006-12-06 20:41:36 -08001918static int
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05001919ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
Alex Tomasa86c6182006-10-11 01:21:03 -07001920 struct ext4_extent *ex)
1921{
1922 struct ext4_ext_cache *cex;
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001923 int ret = EXT4_EXT_CACHE_NO;
Alex Tomasa86c6182006-10-11 01:21:03 -07001924
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001925 /*
1926 * We borrow i_block_reservation_lock to protect i_cached_extent
1927 */
1928 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
Alex Tomasa86c6182006-10-11 01:21:03 -07001929 cex = &EXT4_I(inode)->i_cached_extent;
1930
1931 /* has cache valid data? */
1932 if (cex->ec_type == EXT4_EXT_CACHE_NO)
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001933 goto errout;
Alex Tomasa86c6182006-10-11 01:21:03 -07001934
1935 BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP &&
1936 cex->ec_type != EXT4_EXT_CACHE_EXTENT);
1937 if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001938 ex->ee_block = cpu_to_le32(cex->ec_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001939 ext4_ext_store_pblock(ex, cex->ec_start);
Dave Kleikamp8c55e202007-05-24 13:04:54 -04001940 ex->ee_len = cpu_to_le16(cex->ec_len);
Eric Sandeenbba90742008-01-28 23:58:27 -05001941 ext_debug("%u cached by %u:%u:%llu\n",
1942 block,
1943 cex->ec_block, cex->ec_len, cex->ec_start);
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001944 ret = cex->ec_type;
Alex Tomasa86c6182006-10-11 01:21:03 -07001945 }
Theodore Ts'o2ec0ae32009-05-15 09:07:28 -04001946errout:
1947 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1948 return ret;
Alex Tomasa86c6182006-10-11 01:21:03 -07001949}
1950
1951/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07001952 * ext4_ext_rm_idx:
1953 * removes index from the index block.
1954 * It's used in truncate case only, thus all requests are for
1955 * last index in the block only.
Alex Tomasa86c6182006-10-11 01:21:03 -07001956 */
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05001957static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
Alex Tomasa86c6182006-10-11 01:21:03 -07001958 struct ext4_ext_path *path)
1959{
1960 struct buffer_head *bh;
1961 int err;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001962 ext4_fsblk_t leaf;
Alex Tomasa86c6182006-10-11 01:21:03 -07001963
1964 /* free index block */
1965 path--;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07001966 leaf = idx_pblock(path->p_idx);
Alex Tomasa86c6182006-10-11 01:21:03 -07001967 BUG_ON(path->p_hdr->eh_entries == 0);
Avantika Mathur7e028972006-12-06 20:41:33 -08001968 err = ext4_ext_get_access(handle, inode, path);
1969 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001970 return err;
Marcin Slusarze8546d02008-04-17 10:38:59 -04001971 le16_add_cpu(&path->p_hdr->eh_entries, -1);
Avantika Mathur7e028972006-12-06 20:41:33 -08001972 err = ext4_ext_dirty(handle, inode, path);
1973 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07001974 return err;
Mingming Cao2ae02102006-10-11 01:21:11 -07001975 ext_debug("index is empty, remove it, free block %llu\n", leaf);
Alex Tomasa86c6182006-10-11 01:21:03 -07001976 bh = sb_find_get_block(inode->i_sb, leaf);
1977 ext4_forget(handle, 1, inode, bh, leaf);
Alex Tomasc9de5602008-01-29 00:19:52 -05001978 ext4_free_blocks(handle, inode, leaf, 1, 1);
Alex Tomasa86c6182006-10-11 01:21:03 -07001979 return err;
1980}
1981
1982/*
Mingming Caoee12b632008-08-19 22:16:05 -04001983 * ext4_ext_calc_credits_for_single_extent:
1984 * This routine returns max. credits that needed to insert an extent
1985 * to the extent tree.
1986 * When pass the actual path, the caller should calculate credits
1987 * under i_data_sem.
Alex Tomasa86c6182006-10-11 01:21:03 -07001988 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04001989int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
Alex Tomasa86c6182006-10-11 01:21:03 -07001990 struct ext4_ext_path *path)
1991{
Alex Tomasa86c6182006-10-11 01:21:03 -07001992 if (path) {
Mingming Caoee12b632008-08-19 22:16:05 -04001993 int depth = ext_depth(inode);
Mingming Caof3bd1f32008-08-19 22:16:03 -04001994 int ret = 0;
Mingming Caoee12b632008-08-19 22:16:05 -04001995
Alex Tomasa86c6182006-10-11 01:21:03 -07001996 /* probably there is space in leaf? */
Alex Tomasa86c6182006-10-11 01:21:03 -07001997 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
Mingming Caoee12b632008-08-19 22:16:05 -04001998 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
1999
2000 /*
2001 * There are some space in the leaf tree, no
2002 * need to account for leaf block credit
2003 *
2004 * bitmaps and block group descriptor blocks
2005 * and other metadat blocks still need to be
2006 * accounted.
2007 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04002008 /* 1 bitmap, 1 block group descriptor */
Mingming Caoee12b632008-08-19 22:16:05 -04002009 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
Aneesh Kumar K.V5887e982009-07-05 23:12:04 -04002010 return ret;
Mingming Caoee12b632008-08-19 22:16:05 -04002011 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002012 }
2013
Mingming Cao525f4ed2008-08-19 22:15:58 -04002014 return ext4_chunk_trans_blocks(inode, nrblocks);
Mingming Caoee12b632008-08-19 22:16:05 -04002015}
Alex Tomasa86c6182006-10-11 01:21:03 -07002016
Mingming Caoee12b632008-08-19 22:16:05 -04002017/*
2018 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2019 *
2020 * if nrblocks are fit in a single extent (chunk flag is 1), then
2021 * in the worse case, each tree level index/leaf need to be changed
2022 * if the tree split due to insert a new extent, then the old tree
2023 * index/leaf need to be updated too
2024 *
2025 * If the nrblocks are discontiguous, they could cause
2026 * the whole tree split more than once, but this is really rare.
2027 */
Mingming Cao525f4ed2008-08-19 22:15:58 -04002028int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
Mingming Caoee12b632008-08-19 22:16:05 -04002029{
2030 int index;
2031 int depth = ext_depth(inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07002032
Mingming Caoee12b632008-08-19 22:16:05 -04002033 if (chunk)
2034 index = depth * 2;
2035 else
2036 index = depth * 3;
Alex Tomasa86c6182006-10-11 01:21:03 -07002037
Mingming Caoee12b632008-08-19 22:16:05 -04002038 return index;
Alex Tomasa86c6182006-10-11 01:21:03 -07002039}
2040
2041static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2042 struct ext4_extent *ex,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002043 ext4_lblk_t from, ext4_lblk_t to)
Alex Tomasa86c6182006-10-11 01:21:03 -07002044{
2045 struct buffer_head *bh;
Amit Aroraa2df2a62007-07-17 21:42:41 -04002046 unsigned short ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasc9de5602008-01-29 00:19:52 -05002047 int i, metadata = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07002048
Alex Tomasc9de5602008-01-29 00:19:52 -05002049 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2050 metadata = 1;
Alex Tomasa86c6182006-10-11 01:21:03 -07002051#ifdef EXTENTS_STATS
2052 {
2053 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Alex Tomasa86c6182006-10-11 01:21:03 -07002054 spin_lock(&sbi->s_ext_stats_lock);
2055 sbi->s_ext_blocks += ee_len;
2056 sbi->s_ext_extents++;
2057 if (ee_len < sbi->s_ext_min)
2058 sbi->s_ext_min = ee_len;
2059 if (ee_len > sbi->s_ext_max)
2060 sbi->s_ext_max = ee_len;
2061 if (ext_depth(inode) > sbi->s_depth_max)
2062 sbi->s_depth_max = ext_depth(inode);
2063 spin_unlock(&sbi->s_ext_stats_lock);
2064 }
2065#endif
2066 if (from >= le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04002067 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002068 /* tail removal */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002069 ext4_lblk_t num;
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002070 ext4_fsblk_t start;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002071
Amit Aroraa2df2a62007-07-17 21:42:41 -04002072 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2073 start = ext_pblock(ex) + ee_len - num;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002074 ext_debug("free last %u blocks starting %llu\n", num, start);
Alex Tomasa86c6182006-10-11 01:21:03 -07002075 for (i = 0; i < num; i++) {
2076 bh = sb_find_get_block(inode->i_sb, start + i);
2077 ext4_forget(handle, 0, inode, bh, start + i);
2078 }
Alex Tomasc9de5602008-01-29 00:19:52 -05002079 ext4_free_blocks(handle, inode, start, num, metadata);
Alex Tomasa86c6182006-10-11 01:21:03 -07002080 } else if (from == le32_to_cpu(ex->ee_block)
Amit Aroraa2df2a62007-07-17 21:42:41 -04002081 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002082 printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
Amit Aroraa2df2a62007-07-17 21:42:41 -04002083 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07002084 } else {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002085 printk(KERN_INFO "strange request: removal(2) "
2086 "%u-%u from %u:%u\n",
2087 from, to, le32_to_cpu(ex->ee_block), ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07002088 }
2089 return 0;
2090}
2091
2092static int
2093ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002094 struct ext4_ext_path *path, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07002095{
2096 int err = 0, correct_index = 0;
2097 int depth = ext_depth(inode), credits;
2098 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002099 ext4_lblk_t a, b, block;
2100 unsigned num;
2101 ext4_lblk_t ex_ee_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07002102 unsigned short ex_ee_len;
Amit Aroraa2df2a62007-07-17 21:42:41 -04002103 unsigned uninitialized = 0;
Alex Tomasa86c6182006-10-11 01:21:03 -07002104 struct ext4_extent *ex;
2105
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002106 /* the header must be checked already in ext4_ext_remove_space() */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002107 ext_debug("truncate since %u in leaf\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07002108 if (!path[depth].p_hdr)
2109 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2110 eh = path[depth].p_hdr;
2111 BUG_ON(eh == NULL);
Alex Tomasa86c6182006-10-11 01:21:03 -07002112
2113 /* find where to start removing */
2114 ex = EXT_LAST_EXTENT(eh);
2115
2116 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002117 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002118
2119 while (ex >= EXT_FIRST_EXTENT(eh) &&
2120 ex_ee_block + ex_ee_len > start) {
Aneesh Kumar K.Va41f2072009-06-10 14:22:55 -04002121
2122 if (ext4_ext_is_uninitialized(ex))
2123 uninitialized = 1;
2124 else
2125 uninitialized = 0;
2126
Mingming553f9002009-09-18 13:34:55 -04002127 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2128 uninitialized, ex_ee_len);
Alex Tomasa86c6182006-10-11 01:21:03 -07002129 path[depth].p_ext = ex;
2130
2131 a = ex_ee_block > start ? ex_ee_block : start;
2132 b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ?
2133 ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK;
2134
2135 ext_debug(" border %u:%u\n", a, b);
2136
2137 if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) {
2138 block = 0;
2139 num = 0;
2140 BUG();
2141 } else if (a != ex_ee_block) {
2142 /* remove tail of the extent */
2143 block = ex_ee_block;
2144 num = a - block;
2145 } else if (b != ex_ee_block + ex_ee_len - 1) {
2146 /* remove head of the extent */
2147 block = a;
2148 num = b - a;
2149 /* there is no "make a hole" API yet */
2150 BUG();
2151 } else {
2152 /* remove whole extent: excellent! */
2153 block = ex_ee_block;
2154 num = 0;
2155 BUG_ON(a != ex_ee_block);
2156 BUG_ON(b != ex_ee_block + ex_ee_len - 1);
2157 }
2158
Theodore Ts'o34071da2008-08-01 21:59:19 -04002159 /*
2160 * 3 for leaf, sb, and inode plus 2 (bmap and group
2161 * descriptor) for each block group; assume two block
2162 * groups plus ex_ee_len/blocks_per_block_group for
2163 * the worst case
2164 */
2165 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
Alex Tomasa86c6182006-10-11 01:21:03 -07002166 if (ex == EXT_FIRST_EXTENT(eh)) {
2167 correct_index = 1;
2168 credits += (ext_depth(inode)) + 1;
2169 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002170 credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
Alex Tomasa86c6182006-10-11 01:21:03 -07002171
Jan Kara487caee2009-08-17 22:17:20 -04002172 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
Shen Feng9102e4f2008-07-11 19:27:31 -04002173 if (err)
Alex Tomasa86c6182006-10-11 01:21:03 -07002174 goto out;
Alex Tomasa86c6182006-10-11 01:21:03 -07002175
2176 err = ext4_ext_get_access(handle, inode, path + depth);
2177 if (err)
2178 goto out;
2179
2180 err = ext4_remove_blocks(handle, inode, ex, a, b);
2181 if (err)
2182 goto out;
2183
2184 if (num == 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002185 /* this extent is removed; mark slot entirely unused */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002186 ext4_ext_store_pblock(ex, 0);
Marcin Slusarze8546d02008-04-17 10:38:59 -04002187 le16_add_cpu(&eh->eh_entries, -1);
Alex Tomasa86c6182006-10-11 01:21:03 -07002188 }
2189
2190 ex->ee_block = cpu_to_le32(block);
2191 ex->ee_len = cpu_to_le16(num);
Amit Arora749269f2007-07-18 09:02:56 -04002192 /*
2193 * Do not mark uninitialized if all the blocks in the
2194 * extent have been removed.
2195 */
2196 if (uninitialized && num)
Amit Aroraa2df2a62007-07-17 21:42:41 -04002197 ext4_ext_mark_uninitialized(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002198
2199 err = ext4_ext_dirty(handle, inode, path + depth);
2200 if (err)
2201 goto out;
2202
Mingming Cao2ae02102006-10-11 01:21:11 -07002203 ext_debug("new extent: %u:%u:%llu\n", block, num,
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002204 ext_pblock(ex));
Alex Tomasa86c6182006-10-11 01:21:03 -07002205 ex--;
2206 ex_ee_block = le32_to_cpu(ex->ee_block);
Amit Aroraa2df2a62007-07-17 21:42:41 -04002207 ex_ee_len = ext4_ext_get_actual_len(ex);
Alex Tomasa86c6182006-10-11 01:21:03 -07002208 }
2209
2210 if (correct_index && eh->eh_entries)
2211 err = ext4_ext_correct_indexes(handle, inode, path);
2212
2213 /* if this leaf is free, then we should
2214 * remove it from index block above */
2215 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2216 err = ext4_ext_rm_idx(handle, inode, path + depth);
2217
2218out:
2219 return err;
2220}
2221
2222/*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002223 * ext4_ext_more_to_rm:
2224 * returns 1 if current index has to be freed (even partial)
Alex Tomasa86c6182006-10-11 01:21:03 -07002225 */
Avantika Mathur09b88252006-12-06 20:41:36 -08002226static int
Alex Tomasa86c6182006-10-11 01:21:03 -07002227ext4_ext_more_to_rm(struct ext4_ext_path *path)
2228{
2229 BUG_ON(path->p_idx == NULL);
2230
2231 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2232 return 0;
2233
2234 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002235 * if truncate on deeper level happened, it wasn't partial,
Alex Tomasa86c6182006-10-11 01:21:03 -07002236 * so we have to consider current index for truncation
2237 */
2238 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2239 return 0;
2240 return 1;
2241}
2242
Aneesh Kumar K.V1d03ec92008-01-28 23:58:27 -05002243static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
Alex Tomasa86c6182006-10-11 01:21:03 -07002244{
2245 struct super_block *sb = inode->i_sb;
2246 int depth = ext_depth(inode);
2247 struct ext4_ext_path *path;
2248 handle_t *handle;
2249 int i = 0, err = 0;
2250
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002251 ext_debug("truncate since %u\n", start);
Alex Tomasa86c6182006-10-11 01:21:03 -07002252
2253 /* probably first extent we're gonna free will be last in block */
2254 handle = ext4_journal_start(inode, depth + 1);
2255 if (IS_ERR(handle))
2256 return PTR_ERR(handle);
2257
2258 ext4_ext_invalidate_cache(inode);
2259
2260 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002261 * We start scanning from right side, freeing all the blocks
2262 * after i_size and walking into the tree depth-wise.
Alex Tomasa86c6182006-10-11 01:21:03 -07002263 */
Josef Bacik216553c2008-04-29 22:02:02 -04002264 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
Alex Tomasa86c6182006-10-11 01:21:03 -07002265 if (path == NULL) {
2266 ext4_journal_stop(handle);
2267 return -ENOMEM;
2268 }
Alex Tomasa86c6182006-10-11 01:21:03 -07002269 path[0].p_hdr = ext_inode_hdr(inode);
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -04002270 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002271 err = -EIO;
2272 goto out;
2273 }
2274 path[0].p_depth = depth;
2275
2276 while (i >= 0 && err == 0) {
2277 if (i == depth) {
2278 /* this is leaf block */
2279 err = ext4_ext_rm_leaf(handle, inode, path, start);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002280 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07002281 brelse(path[i].p_bh);
2282 path[i].p_bh = NULL;
2283 i--;
2284 continue;
2285 }
2286
2287 /* this is index block */
2288 if (!path[i].p_hdr) {
2289 ext_debug("initialize header\n");
2290 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
Alex Tomasa86c6182006-10-11 01:21:03 -07002291 }
2292
Alex Tomasa86c6182006-10-11 01:21:03 -07002293 if (!path[i].p_idx) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002294 /* this level hasn't been touched yet */
Alex Tomasa86c6182006-10-11 01:21:03 -07002295 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2296 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2297 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2298 path[i].p_hdr,
2299 le16_to_cpu(path[i].p_hdr->eh_entries));
2300 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002301 /* we were already here, see at next index */
Alex Tomasa86c6182006-10-11 01:21:03 -07002302 path[i].p_idx--;
2303 }
2304
2305 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2306 i, EXT_FIRST_INDEX(path[i].p_hdr),
2307 path[i].p_idx);
2308 if (ext4_ext_more_to_rm(path + i)) {
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002309 struct buffer_head *bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002310 /* go to the next level */
Mingming Cao2ae02102006-10-11 01:21:11 -07002311 ext_debug("move to level %d (block %llu)\n",
Alex Tomasf65e6fb2006-10-11 01:21:05 -07002312 i + 1, idx_pblock(path[i].p_idx));
Alex Tomasa86c6182006-10-11 01:21:03 -07002313 memset(path + i + 1, 0, sizeof(*path));
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002314 bh = sb_bread(sb, idx_pblock(path[i].p_idx));
2315 if (!bh) {
Alex Tomasa86c6182006-10-11 01:21:03 -07002316 /* should we reset i_size? */
2317 err = -EIO;
2318 break;
2319 }
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002320 if (WARN_ON(i + 1 > depth)) {
2321 err = -EIO;
2322 break;
2323 }
Aneesh Kumar K.V56b19862009-03-12 09:51:20 -04002324 if (ext4_ext_check(inode, ext_block_hdr(bh),
Alex Tomasc29c0ae2007-07-18 09:19:09 -04002325 depth - i - 1)) {
2326 err = -EIO;
2327 break;
2328 }
2329 path[i + 1].p_bh = bh;
Alex Tomasa86c6182006-10-11 01:21:03 -07002330
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002331 /* save actual number of indexes since this
2332 * number is changed at the next iteration */
Alex Tomasa86c6182006-10-11 01:21:03 -07002333 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2334 i++;
2335 } else {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002336 /* we finished processing this index, go up */
Alex Tomasa86c6182006-10-11 01:21:03 -07002337 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002338 /* index is empty, remove it;
Alex Tomasa86c6182006-10-11 01:21:03 -07002339 * handle must be already prepared by the
2340 * truncatei_leaf() */
2341 err = ext4_ext_rm_idx(handle, inode, path + i);
2342 }
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002343 /* root level has p_bh == NULL, brelse() eats this */
Alex Tomasa86c6182006-10-11 01:21:03 -07002344 brelse(path[i].p_bh);
2345 path[i].p_bh = NULL;
2346 i--;
2347 ext_debug("return to level %d\n", i);
2348 }
2349 }
2350
2351 /* TODO: flexible tree reduction should be here */
2352 if (path->p_hdr->eh_entries == 0) {
2353 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07002354 * truncate to zero freed all the tree,
2355 * so we need to correct eh_depth
Alex Tomasa86c6182006-10-11 01:21:03 -07002356 */
2357 err = ext4_ext_get_access(handle, inode, path);
2358 if (err == 0) {
2359 ext_inode_hdr(inode)->eh_depth = 0;
2360 ext_inode_hdr(inode)->eh_max =
Theodore Ts'o55ad63b2009-08-28 10:40:33 -04002361 cpu_to_le16(ext4_ext_space_root(inode, 0));
Alex Tomasa86c6182006-10-11 01:21:03 -07002362 err = ext4_ext_dirty(handle, inode, path);
2363 }
2364 }
2365out:
Alex Tomasa86c6182006-10-11 01:21:03 -07002366 ext4_ext_drop_refs(path);
2367 kfree(path);
2368 ext4_journal_stop(handle);
2369
2370 return err;
2371}
2372
2373/*
2374 * called at mount time
2375 */
2376void ext4_ext_init(struct super_block *sb)
2377{
2378 /*
2379 * possible initialization would be here
2380 */
2381
Theodore Ts'o83982b62009-01-06 14:53:16 -05002382 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
Theodore Ts'o90576c02009-09-29 15:51:30 -04002383#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
Theodore Ts'o4776004f2008-09-08 23:00:52 -04002384 printk(KERN_INFO "EXT4-fs: file extents enabled");
Robert P. J. Daybbf2f9f2007-02-17 19:20:16 +01002385#ifdef AGGRESSIVE_TEST
2386 printk(", aggressive tests");
Alex Tomasa86c6182006-10-11 01:21:03 -07002387#endif
2388#ifdef CHECK_BINSEARCH
2389 printk(", check binsearch");
2390#endif
2391#ifdef EXTENTS_STATS
2392 printk(", stats");
2393#endif
2394 printk("\n");
Theodore Ts'o90576c02009-09-29 15:51:30 -04002395#endif
Alex Tomasa86c6182006-10-11 01:21:03 -07002396#ifdef EXTENTS_STATS
2397 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2398 EXT4_SB(sb)->s_ext_min = 1 << 30;
2399 EXT4_SB(sb)->s_ext_max = 0;
2400#endif
2401 }
2402}
2403
2404/*
2405 * called at umount time
2406 */
2407void ext4_ext_release(struct super_block *sb)
2408{
Theodore Ts'o83982b62009-01-06 14:53:16 -05002409 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
Alex Tomasa86c6182006-10-11 01:21:03 -07002410 return;
2411
2412#ifdef EXTENTS_STATS
2413 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2414 struct ext4_sb_info *sbi = EXT4_SB(sb);
2415 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2416 sbi->s_ext_blocks, sbi->s_ext_extents,
2417 sbi->s_ext_blocks / sbi->s_ext_extents);
2418 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2419 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2420 }
2421#endif
2422}
2423
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002424static void bi_complete(struct bio *bio, int error)
2425{
2426 complete((struct completion *)bio->bi_private);
2427}
2428
2429/* FIXME!! we need to try to merge to left or right after zero-out */
2430static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2431{
2432 int ret = -EIO;
2433 struct bio *bio;
2434 int blkbits, blocksize;
2435 sector_t ee_pblock;
2436 struct completion event;
2437 unsigned int ee_len, len, done, offset;
2438
2439
2440 blkbits = inode->i_blkbits;
2441 blocksize = inode->i_sb->s_blocksize;
2442 ee_len = ext4_ext_get_actual_len(ex);
2443 ee_pblock = ext_pblock(ex);
2444
2445 /* convert ee_pblock to 512 byte sectors */
2446 ee_pblock = ee_pblock << (blkbits - 9);
2447
2448 while (ee_len > 0) {
2449
2450 if (ee_len > BIO_MAX_PAGES)
2451 len = BIO_MAX_PAGES;
2452 else
2453 len = ee_len;
2454
2455 bio = bio_alloc(GFP_NOIO, len);
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002456 bio->bi_sector = ee_pblock;
2457 bio->bi_bdev = inode->i_sb->s_bdev;
2458
2459 done = 0;
2460 offset = 0;
2461 while (done < len) {
2462 ret = bio_add_page(bio, ZERO_PAGE(0),
2463 blocksize, offset);
2464 if (ret != blocksize) {
2465 /*
2466 * We can't add any more pages because of
2467 * hardware limitations. Start a new bio.
2468 */
2469 break;
2470 }
2471 done++;
2472 offset += blocksize;
2473 if (offset >= PAGE_CACHE_SIZE)
2474 offset = 0;
2475 }
2476
2477 init_completion(&event);
2478 bio->bi_private = &event;
2479 bio->bi_end_io = bi_complete;
2480 submit_bio(WRITE, bio);
2481 wait_for_completion(&event);
2482
2483 if (test_bit(BIO_UPTODATE, &bio->bi_flags))
2484 ret = 0;
2485 else {
2486 ret = -EIO;
2487 break;
2488 }
2489 bio_put(bio);
2490 ee_len -= done;
2491 ee_pblock += done << (blkbits - 9);
2492 }
2493 return ret;
2494}
2495
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002496#define EXT4_EXT_ZERO_LEN 7
Amit Arora56055d32007-07-17 21:42:38 -04002497/*
2498 * This function is called by ext4_ext_get_blocks() if someone tries to write
2499 * to an uninitialized extent. It may result in splitting the uninitialized
2500 * extent into multiple extents (upto three - one initialized and two
2501 * uninitialized).
2502 * There are three possibilities:
2503 * a> There is no split required: Entire extent should be initialized
2504 * b> Splits in two extents: Write is happening at either end of the extent
2505 * c> Splits in three extents: Somone is writing in middle of the extent
2506 */
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002507static int ext4_ext_convert_to_initialized(handle_t *handle,
2508 struct inode *inode,
2509 struct ext4_ext_path *path,
2510 ext4_lblk_t iblock,
Theodore Ts'o498e5f22008-11-05 00:14:04 -05002511 unsigned int max_blocks)
Amit Arora56055d32007-07-17 21:42:38 -04002512{
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002513 struct ext4_extent *ex, newex, orig_ex;
Amit Arora56055d32007-07-17 21:42:38 -04002514 struct ext4_extent *ex1 = NULL;
2515 struct ext4_extent *ex2 = NULL;
2516 struct ext4_extent *ex3 = NULL;
2517 struct ext4_extent_header *eh;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05002518 ext4_lblk_t ee_block;
2519 unsigned int allocated, ee_len, depth;
Amit Arora56055d32007-07-17 21:42:38 -04002520 ext4_fsblk_t newblock;
2521 int err = 0;
2522 int ret = 0;
2523
2524 depth = ext_depth(inode);
2525 eh = path[depth].p_hdr;
2526 ex = path[depth].p_ext;
2527 ee_block = le32_to_cpu(ex->ee_block);
2528 ee_len = ext4_ext_get_actual_len(ex);
2529 allocated = ee_len - (iblock - ee_block);
2530 newblock = iblock - ee_block + ext_pblock(ex);
2531 ex2 = ex;
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002532 orig_ex.ee_block = ex->ee_block;
2533 orig_ex.ee_len = cpu_to_le16(ee_len);
2534 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
Amit Arora56055d32007-07-17 21:42:38 -04002535
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002536 err = ext4_ext_get_access(handle, inode, path + depth);
2537 if (err)
2538 goto out;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002539 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
2540 if (ee_len <= 2*EXT4_EXT_ZERO_LEN) {
2541 err = ext4_ext_zeroout(inode, &orig_ex);
2542 if (err)
2543 goto fix_extent_len;
2544 /* update the extent length and mark as initialized */
2545 ex->ee_block = orig_ex.ee_block;
2546 ex->ee_len = orig_ex.ee_len;
2547 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2548 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002549 /* zeroed the full extent */
2550 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002551 }
Aneesh Kumar K.V9df56432008-02-22 06:17:31 -05002552
Amit Arora56055d32007-07-17 21:42:38 -04002553 /* ex1: ee_block to iblock - 1 : uninitialized */
2554 if (iblock > ee_block) {
2555 ex1 = ex;
2556 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2557 ext4_ext_mark_uninitialized(ex1);
2558 ex2 = &newex;
2559 }
2560 /*
2561 * for sanity, update the length of the ex2 extent before
2562 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2563 * overlap of blocks.
2564 */
2565 if (!ex1 && allocated > max_blocks)
2566 ex2->ee_len = cpu_to_le16(max_blocks);
2567 /* ex3: to ee_block + ee_len : uninitialised */
2568 if (allocated > max_blocks) {
2569 unsigned int newdepth;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002570 /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
2571 if (allocated <= EXT4_EXT_ZERO_LEN) {
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002572 /*
2573 * iblock == ee_block is handled by the zerouout
2574 * at the beginning.
2575 * Mark first half uninitialized.
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002576 * Mark second half initialized and zero out the
2577 * initialized extent
2578 */
2579 ex->ee_block = orig_ex.ee_block;
2580 ex->ee_len = cpu_to_le16(ee_len - allocated);
2581 ext4_ext_mark_uninitialized(ex);
2582 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2583 ext4_ext_dirty(handle, inode, path + depth);
2584
2585 ex3 = &newex;
2586 ex3->ee_block = cpu_to_le32(iblock);
2587 ext4_ext_store_pblock(ex3, newblock);
2588 ex3->ee_len = cpu_to_le16(allocated);
Mingming Cao00314622009-09-28 15:49:08 -04002589 err = ext4_ext_insert_extent(handle, inode, path,
2590 ex3, 0);
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002591 if (err == -ENOSPC) {
2592 err = ext4_ext_zeroout(inode, &orig_ex);
2593 if (err)
2594 goto fix_extent_len;
2595 ex->ee_block = orig_ex.ee_block;
2596 ex->ee_len = orig_ex.ee_len;
2597 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2598 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002599 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002600 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002601
2602 } else if (err)
2603 goto fix_extent_len;
2604
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002605 /*
2606 * We need to zero out the second half because
2607 * an fallocate request can update file size and
2608 * converting the second half to initialized extent
2609 * implies that we can leak some junk data to user
2610 * space.
2611 */
2612 err = ext4_ext_zeroout(inode, ex3);
2613 if (err) {
2614 /*
2615 * We should actually mark the
2616 * second half as uninit and return error
2617 * Insert would have changed the extent
2618 */
2619 depth = ext_depth(inode);
2620 ext4_ext_drop_refs(path);
2621 path = ext4_ext_find_extent(inode,
2622 iblock, path);
2623 if (IS_ERR(path)) {
2624 err = PTR_ERR(path);
2625 return err;
2626 }
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002627 /* get the second half extent details */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002628 ex = path[depth].p_ext;
2629 err = ext4_ext_get_access(handle, inode,
2630 path + depth);
2631 if (err)
2632 return err;
2633 ext4_ext_mark_uninitialized(ex);
2634 ext4_ext_dirty(handle, inode, path + depth);
2635 return err;
2636 }
2637
2638 /* zeroed the second half */
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002639 return allocated;
2640 }
Amit Arora56055d32007-07-17 21:42:38 -04002641 ex3 = &newex;
2642 ex3->ee_block = cpu_to_le32(iblock + max_blocks);
2643 ext4_ext_store_pblock(ex3, newblock + max_blocks);
2644 ex3->ee_len = cpu_to_le16(allocated - max_blocks);
2645 ext4_ext_mark_uninitialized(ex3);
Mingming Cao00314622009-09-28 15:49:08 -04002646 err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002647 if (err == -ENOSPC) {
2648 err = ext4_ext_zeroout(inode, &orig_ex);
2649 if (err)
2650 goto fix_extent_len;
2651 /* update the extent length and mark as initialized */
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002652 ex->ee_block = orig_ex.ee_block;
2653 ex->ee_len = orig_ex.ee_len;
2654 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002655 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002656 /* zeroed the full extent */
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002657 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002658 return allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002659
2660 } else if (err)
2661 goto fix_extent_len;
Amit Arora56055d32007-07-17 21:42:38 -04002662 /*
2663 * The depth, and hence eh & ex might change
2664 * as part of the insert above.
2665 */
2666 newdepth = ext_depth(inode);
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002667 /*
Coly Li73ac36e2009-01-07 18:09:16 -08002668 * update the extent length after successful insert of the
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002669 * split extent
2670 */
2671 orig_ex.ee_len = cpu_to_le16(ee_len -
2672 ext4_ext_get_actual_len(ex3));
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002673 depth = newdepth;
2674 ext4_ext_drop_refs(path);
2675 path = ext4_ext_find_extent(inode, iblock, path);
2676 if (IS_ERR(path)) {
2677 err = PTR_ERR(path);
2678 goto out;
Amit Arora56055d32007-07-17 21:42:38 -04002679 }
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002680 eh = path[depth].p_hdr;
2681 ex = path[depth].p_ext;
2682 if (ex2 != &newex)
2683 ex2 = ex;
2684
2685 err = ext4_ext_get_access(handle, inode, path + depth);
2686 if (err)
2687 goto out;
2688
Amit Arora56055d32007-07-17 21:42:38 -04002689 allocated = max_blocks;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002690
2691 /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
2692 * to insert a extent in the middle zerout directly
2693 * otherwise give the extent a chance to merge to left
2694 */
2695 if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
2696 iblock != ee_block) {
2697 err = ext4_ext_zeroout(inode, &orig_ex);
2698 if (err)
2699 goto fix_extent_len;
2700 /* update the extent length and mark as initialized */
2701 ex->ee_block = orig_ex.ee_block;
2702 ex->ee_len = orig_ex.ee_len;
2703 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2704 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002705 /* zero out the first half */
Aneesh Kumar K.Vd03856b2008-08-02 18:51:32 -04002706 /* blocks available from iblock */
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002707 return allocated;
Aneesh Kumar K.V3977c962008-04-17 10:38:59 -04002708 }
Amit Arora56055d32007-07-17 21:42:38 -04002709 }
2710 /*
2711 * If there was a change of depth as part of the
2712 * insertion of ex3 above, we need to update the length
2713 * of the ex1 extent again here
2714 */
2715 if (ex1 && ex1 != ex) {
2716 ex1 = ex;
2717 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2718 ext4_ext_mark_uninitialized(ex1);
2719 ex2 = &newex;
2720 }
2721 /* ex2: iblock to iblock + maxblocks-1 : initialised */
2722 ex2->ee_block = cpu_to_le32(iblock);
Amit Arora56055d32007-07-17 21:42:38 -04002723 ext4_ext_store_pblock(ex2, newblock);
2724 ex2->ee_len = cpu_to_le16(allocated);
2725 if (ex2 != ex)
2726 goto insert;
Amit Arora56055d32007-07-17 21:42:38 -04002727 /*
2728 * New (initialized) extent starts from the first block
2729 * in the current extent. i.e., ex2 == ex
2730 * We have to see if it can be merged with the extent
2731 * on the left.
2732 */
2733 if (ex2 > EXT_FIRST_EXTENT(eh)) {
2734 /*
2735 * To merge left, pass "ex2 - 1" to try_to_merge(),
2736 * since it merges towards right _only_.
2737 */
2738 ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
2739 if (ret) {
2740 err = ext4_ext_correct_indexes(handle, inode, path);
2741 if (err)
2742 goto out;
2743 depth = ext_depth(inode);
2744 ex2--;
2745 }
2746 }
2747 /*
2748 * Try to Merge towards right. This might be required
2749 * only when the whole extent is being written to.
2750 * i.e. ex2 == ex and ex3 == NULL.
2751 */
2752 if (!ex3) {
2753 ret = ext4_ext_try_to_merge(inode, path, ex2);
2754 if (ret) {
2755 err = ext4_ext_correct_indexes(handle, inode, path);
2756 if (err)
2757 goto out;
2758 }
2759 }
2760 /* Mark modified extent as dirty */
2761 err = ext4_ext_dirty(handle, inode, path + depth);
2762 goto out;
2763insert:
Mingming Cao00314622009-09-28 15:49:08 -04002764 err = ext4_ext_insert_extent(handle, inode, path, &newex, 0);
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002765 if (err == -ENOSPC) {
2766 err = ext4_ext_zeroout(inode, &orig_ex);
2767 if (err)
2768 goto fix_extent_len;
2769 /* update the extent length and mark as initialized */
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002770 ex->ee_block = orig_ex.ee_block;
2771 ex->ee_len = orig_ex.ee_len;
2772 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
Aneesh Kumar K.V95c38892008-04-17 10:38:59 -04002773 ext4_ext_dirty(handle, inode, path + depth);
Aneesh Kumar K.V161e7b72008-04-29 22:03:59 -04002774 /* zero out the first half */
2775 return allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002776 } else if (err)
2777 goto fix_extent_len;
Amit Arora56055d32007-07-17 21:42:38 -04002778out:
Mingming553f9002009-09-18 13:34:55 -04002779 ext4_ext_show_leaf(inode, path);
Amit Arora56055d32007-07-17 21:42:38 -04002780 return err ? err : allocated;
Aneesh Kumar K.V093a0882008-04-29 08:11:12 -04002781
2782fix_extent_len:
2783 ex->ee_block = orig_ex.ee_block;
2784 ex->ee_len = orig_ex.ee_len;
2785 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2786 ext4_ext_mark_uninitialized(ex);
2787 ext4_ext_dirty(handle, inode, path + depth);
2788 return err;
Amit Arora56055d32007-07-17 21:42:38 -04002789}
2790
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05002791/*
Mingming Cao00314622009-09-28 15:49:08 -04002792 * This function is called by ext4_ext_get_blocks() from
2793 * ext4_get_blocks_dio_write() when DIO to write
2794 * to an uninitialized extent.
2795 *
2796 * Writing to an uninitized extent may result in splitting the uninitialized
2797 * extent into multiple /intialized unintialized extents (up to three)
2798 * There are three possibilities:
2799 * a> There is no split required: Entire extent should be uninitialized
2800 * b> Splits in two extents: Write is happening at either end of the extent
2801 * c> Splits in three extents: Somone is writing in middle of the extent
2802 *
2803 * One of more index blocks maybe needed if the extent tree grow after
2804 * the unintialized extent split. To prevent ENOSPC occur at the IO
2805 * complete, we need to split the uninitialized extent before DIO submit
2806 * the IO. The uninitilized extent called at this time will be split
2807 * into three uninitialized extent(at most). After IO complete, the part
2808 * being filled will be convert to initialized by the end_io callback function
2809 * via ext4_convert_unwritten_extents().
Mingmingba230c32009-11-06 04:01:23 -05002810 *
2811 * Returns the size of uninitialized extent to be written on success.
Mingming Cao00314622009-09-28 15:49:08 -04002812 */
2813static int ext4_split_unwritten_extents(handle_t *handle,
2814 struct inode *inode,
2815 struct ext4_ext_path *path,
2816 ext4_lblk_t iblock,
2817 unsigned int max_blocks,
2818 int flags)
2819{
2820 struct ext4_extent *ex, newex, orig_ex;
2821 struct ext4_extent *ex1 = NULL;
2822 struct ext4_extent *ex2 = NULL;
2823 struct ext4_extent *ex3 = NULL;
2824 struct ext4_extent_header *eh;
2825 ext4_lblk_t ee_block;
2826 unsigned int allocated, ee_len, depth;
2827 ext4_fsblk_t newblock;
2828 int err = 0;
Mingming Cao00314622009-09-28 15:49:08 -04002829
2830 ext_debug("ext4_split_unwritten_extents: inode %lu,"
2831 "iblock %llu, max_blocks %u\n", inode->i_ino,
2832 (unsigned long long)iblock, max_blocks);
2833 depth = ext_depth(inode);
2834 eh = path[depth].p_hdr;
2835 ex = path[depth].p_ext;
2836 ee_block = le32_to_cpu(ex->ee_block);
2837 ee_len = ext4_ext_get_actual_len(ex);
2838 allocated = ee_len - (iblock - ee_block);
2839 newblock = iblock - ee_block + ext_pblock(ex);
2840 ex2 = ex;
2841 orig_ex.ee_block = ex->ee_block;
2842 orig_ex.ee_len = cpu_to_le16(ee_len);
2843 ext4_ext_store_pblock(&orig_ex, ext_pblock(ex));
2844
2845 /*
Mingmingba230c32009-11-06 04:01:23 -05002846 * If the uninitialized extent begins at the same logical
2847 * block where the write begins, and the write completely
2848 * covers the extent, then we don't need to split it.
Mingming Cao00314622009-09-28 15:49:08 -04002849 */
Mingmingba230c32009-11-06 04:01:23 -05002850 if ((iblock == ee_block) && (allocated <= max_blocks))
2851 return allocated;
Mingming Cao00314622009-09-28 15:49:08 -04002852
2853 err = ext4_ext_get_access(handle, inode, path + depth);
2854 if (err)
2855 goto out;
2856 /* ex1: ee_block to iblock - 1 : uninitialized */
2857 if (iblock > ee_block) {
2858 ex1 = ex;
2859 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2860 ext4_ext_mark_uninitialized(ex1);
2861 ex2 = &newex;
2862 }
2863 /*
2864 * for sanity, update the length of the ex2 extent before
2865 * we insert ex3, if ex1 is NULL. This is to avoid temporary
2866 * overlap of blocks.
2867 */
2868 if (!ex1 && allocated > max_blocks)
2869 ex2->ee_len = cpu_to_le16(max_blocks);
2870 /* ex3: to ee_block + ee_len : uninitialised */
2871 if (allocated > max_blocks) {
2872 unsigned int newdepth;
2873 ex3 = &newex;
2874 ex3->ee_block = cpu_to_le32(iblock + max_blocks);
2875 ext4_ext_store_pblock(ex3, newblock + max_blocks);
2876 ex3->ee_len = cpu_to_le16(allocated - max_blocks);
2877 ext4_ext_mark_uninitialized(ex3);
2878 err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
2879 if (err == -ENOSPC) {
2880 err = ext4_ext_zeroout(inode, &orig_ex);
2881 if (err)
2882 goto fix_extent_len;
2883 /* update the extent length and mark as initialized */
2884 ex->ee_block = orig_ex.ee_block;
2885 ex->ee_len = orig_ex.ee_len;
2886 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2887 ext4_ext_dirty(handle, inode, path + depth);
2888 /* zeroed the full extent */
2889 /* blocks available from iblock */
2890 return allocated;
2891
2892 } else if (err)
2893 goto fix_extent_len;
2894 /*
2895 * The depth, and hence eh & ex might change
2896 * as part of the insert above.
2897 */
2898 newdepth = ext_depth(inode);
2899 /*
2900 * update the extent length after successful insert of the
2901 * split extent
2902 */
2903 orig_ex.ee_len = cpu_to_le16(ee_len -
2904 ext4_ext_get_actual_len(ex3));
2905 depth = newdepth;
2906 ext4_ext_drop_refs(path);
2907 path = ext4_ext_find_extent(inode, iblock, path);
2908 if (IS_ERR(path)) {
2909 err = PTR_ERR(path);
2910 goto out;
2911 }
2912 eh = path[depth].p_hdr;
2913 ex = path[depth].p_ext;
2914 if (ex2 != &newex)
2915 ex2 = ex;
2916
2917 err = ext4_ext_get_access(handle, inode, path + depth);
2918 if (err)
2919 goto out;
2920
2921 allocated = max_blocks;
2922 }
2923 /*
2924 * If there was a change of depth as part of the
2925 * insertion of ex3 above, we need to update the length
2926 * of the ex1 extent again here
2927 */
2928 if (ex1 && ex1 != ex) {
2929 ex1 = ex;
2930 ex1->ee_len = cpu_to_le16(iblock - ee_block);
2931 ext4_ext_mark_uninitialized(ex1);
2932 ex2 = &newex;
2933 }
2934 /*
2935 * ex2: iblock to iblock + maxblocks-1 : to be direct IO written,
2936 * uninitialised still.
2937 */
2938 ex2->ee_block = cpu_to_le32(iblock);
2939 ext4_ext_store_pblock(ex2, newblock);
2940 ex2->ee_len = cpu_to_le16(allocated);
2941 ext4_ext_mark_uninitialized(ex2);
2942 if (ex2 != ex)
2943 goto insert;
2944 /* Mark modified extent as dirty */
2945 err = ext4_ext_dirty(handle, inode, path + depth);
2946 ext_debug("out here\n");
2947 goto out;
2948insert:
2949 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
2950 if (err == -ENOSPC) {
2951 err = ext4_ext_zeroout(inode, &orig_ex);
2952 if (err)
2953 goto fix_extent_len;
2954 /* update the extent length and mark as initialized */
2955 ex->ee_block = orig_ex.ee_block;
2956 ex->ee_len = orig_ex.ee_len;
2957 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2958 ext4_ext_dirty(handle, inode, path + depth);
2959 /* zero out the first half */
2960 return allocated;
2961 } else if (err)
2962 goto fix_extent_len;
2963out:
2964 ext4_ext_show_leaf(inode, path);
2965 return err ? err : allocated;
2966
2967fix_extent_len:
2968 ex->ee_block = orig_ex.ee_block;
2969 ex->ee_len = orig_ex.ee_len;
2970 ext4_ext_store_pblock(ex, ext_pblock(&orig_ex));
2971 ext4_ext_mark_uninitialized(ex);
2972 ext4_ext_dirty(handle, inode, path + depth);
2973 return err;
2974}
2975static int ext4_convert_unwritten_extents_dio(handle_t *handle,
2976 struct inode *inode,
2977 struct ext4_ext_path *path)
2978{
2979 struct ext4_extent *ex;
2980 struct ext4_extent_header *eh;
2981 int depth;
2982 int err = 0;
2983 int ret = 0;
2984
2985 depth = ext_depth(inode);
2986 eh = path[depth].p_hdr;
2987 ex = path[depth].p_ext;
2988
2989 err = ext4_ext_get_access(handle, inode, path + depth);
2990 if (err)
2991 goto out;
2992 /* first mark the extent as initialized */
2993 ext4_ext_mark_initialized(ex);
2994
2995 /*
2996 * We have to see if it can be merged with the extent
2997 * on the left.
2998 */
2999 if (ex > EXT_FIRST_EXTENT(eh)) {
3000 /*
3001 * To merge left, pass "ex - 1" to try_to_merge(),
3002 * since it merges towards right _only_.
3003 */
3004 ret = ext4_ext_try_to_merge(inode, path, ex - 1);
3005 if (ret) {
3006 err = ext4_ext_correct_indexes(handle, inode, path);
3007 if (err)
3008 goto out;
3009 depth = ext_depth(inode);
3010 ex--;
3011 }
3012 }
3013 /*
3014 * Try to Merge towards right.
3015 */
3016 ret = ext4_ext_try_to_merge(inode, path, ex);
3017 if (ret) {
3018 err = ext4_ext_correct_indexes(handle, inode, path);
3019 if (err)
3020 goto out;
3021 depth = ext_depth(inode);
3022 }
3023 /* Mark modified extent as dirty */
3024 err = ext4_ext_dirty(handle, inode, path + depth);
3025out:
3026 ext4_ext_show_leaf(inode, path);
3027 return err;
3028}
3029
3030static int
3031ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3032 ext4_lblk_t iblock, unsigned int max_blocks,
3033 struct ext4_ext_path *path, int flags,
3034 unsigned int allocated, struct buffer_head *bh_result,
3035 ext4_fsblk_t newblock)
3036{
3037 int ret = 0;
3038 int err = 0;
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003039 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
Mingming Cao00314622009-09-28 15:49:08 -04003040
3041 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
3042 "block %llu, max_blocks %u, flags %d, allocated %u",
3043 inode->i_ino, (unsigned long long)iblock, max_blocks,
3044 flags, allocated);
3045 ext4_ext_show_leaf(inode, path);
3046
3047 /* DIO get_block() before submit the IO, split the extent */
3048 if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
3049 ret = ext4_split_unwritten_extents(handle,
3050 inode, path, iblock,
3051 max_blocks, flags);
Mingming5f524952009-11-10 10:48:04 -05003052 /*
3053 * Flag the inode(non aio case) or end_io struct (aio case)
3054 * that this IO needs to convertion to written when IO is
3055 * completed
3056 */
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003057 if (io)
3058 io->flag = DIO_AIO_UNWRITTEN;
Mingming5f524952009-11-10 10:48:04 -05003059 else
3060 EXT4_I(inode)->i_state |= EXT4_STATE_DIO_UNWRITTEN;
Mingming Cao00314622009-09-28 15:49:08 -04003061 goto out;
3062 }
Mingming5f524952009-11-10 10:48:04 -05003063 /* async DIO end_io complete, convert the filled extent to written */
Mingming Cao00314622009-09-28 15:49:08 -04003064 if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) {
3065 ret = ext4_convert_unwritten_extents_dio(handle, inode,
3066 path);
3067 goto out2;
3068 }
3069 /* buffered IO case */
3070 /*
3071 * repeat fallocate creation request
3072 * we already have an unwritten extent
3073 */
3074 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
3075 goto map_out;
3076
3077 /* buffered READ or buffered write_begin() lookup */
3078 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3079 /*
3080 * We have blocks reserved already. We
3081 * return allocated blocks so that delalloc
3082 * won't do block reservation for us. But
3083 * the buffer head will be unmapped so that
3084 * a read from the block returns 0s.
3085 */
3086 set_buffer_unwritten(bh_result);
3087 goto out1;
3088 }
3089
3090 /* buffered write, writepage time, convert*/
3091 ret = ext4_ext_convert_to_initialized(handle, inode,
3092 path, iblock,
3093 max_blocks);
3094out:
3095 if (ret <= 0) {
3096 err = ret;
3097 goto out2;
3098 } else
3099 allocated = ret;
3100 set_buffer_new(bh_result);
3101map_out:
3102 set_buffer_mapped(bh_result);
3103out1:
3104 if (allocated > max_blocks)
3105 allocated = max_blocks;
3106 ext4_ext_show_leaf(inode, path);
3107 bh_result->b_bdev = inode->i_sb->s_bdev;
3108 bh_result->b_blocknr = newblock;
3109out2:
3110 if (path) {
3111 ext4_ext_drop_refs(path);
3112 kfree(path);
3113 }
3114 return err ? err : allocated;
3115}
3116/*
Mingming Caof5ab0d12008-02-25 15:29:55 -05003117 * Block allocation/map/preallocation routine for extents based files
3118 *
3119 *
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05003120 * Need to be called with
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05003121 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3122 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
Mingming Caof5ab0d12008-02-25 15:29:55 -05003123 *
3124 * return > 0, number of of blocks already mapped/allocated
3125 * if create == 0 and these are pre-allocated blocks
3126 * buffer head is unmapped
3127 * otherwise blocks are mapped
3128 *
3129 * return = 0, if plain look up failed (blocks have not been allocated)
3130 * buffer head is unmapped
3131 *
3132 * return < 0, error case.
Aneesh Kumar K.Vc278bfe2008-01-28 23:58:27 -05003133 */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07003134int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003135 ext4_lblk_t iblock,
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003136 unsigned int max_blocks, struct buffer_head *bh_result,
Theodore Ts'oc2177052009-05-14 00:58:52 -04003137 int flags)
Alex Tomasa86c6182006-10-11 01:21:03 -07003138{
3139 struct ext4_ext_path *path = NULL;
Amit Arora56055d32007-07-17 21:42:38 -04003140 struct ext4_extent_header *eh;
Alex Tomasa86c6182006-10-11 01:21:03 -07003141 struct ext4_extent newex, *ex;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003142 ext4_fsblk_t newblock;
3143 int err = 0, depth, ret, cache_type;
3144 unsigned int allocated = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05003145 struct ext4_allocation_request ar;
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003146 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
Alex Tomasa86c6182006-10-11 01:21:03 -07003147
3148 __clear_bit(BH_New, &bh_result->b_state);
Mingming84fe3be2009-09-01 08:44:37 -04003149 ext_debug("blocks %u/%u requested for inode %lu\n",
Eric Sandeenbba90742008-01-28 23:58:27 -05003150 iblock, max_blocks, inode->i_ino);
Alex Tomasa86c6182006-10-11 01:21:03 -07003151
3152 /* check in cache */
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003153 cache_type = ext4_ext_in_cache(inode, iblock, &newex);
3154 if (cache_type) {
3155 if (cache_type == EXT4_EXT_CACHE_GAP) {
Theodore Ts'oc2177052009-05-14 00:58:52 -04003156 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
Amit Arora56055d32007-07-17 21:42:38 -04003157 /*
3158 * block isn't allocated yet and
3159 * user doesn't want to allocate it
3160 */
Alex Tomasa86c6182006-10-11 01:21:03 -07003161 goto out2;
3162 }
3163 /* we should allocate requested block */
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003164 } else if (cache_type == EXT4_EXT_CACHE_EXTENT) {
Alex Tomasa86c6182006-10-11 01:21:03 -07003165 /* block is already allocated */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04003166 newblock = iblock
3167 - le32_to_cpu(newex.ee_block)
3168 + ext_pblock(&newex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003169 /* number of remaining blocks in the extent */
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05003170 allocated = ext4_ext_get_actual_len(&newex) -
Alex Tomasa86c6182006-10-11 01:21:03 -07003171 (iblock - le32_to_cpu(newex.ee_block));
3172 goto out;
3173 } else {
3174 BUG();
3175 }
3176 }
3177
3178 /* find extent for this block */
3179 path = ext4_ext_find_extent(inode, iblock, NULL);
3180 if (IS_ERR(path)) {
3181 err = PTR_ERR(path);
3182 path = NULL;
3183 goto out2;
3184 }
3185
3186 depth = ext_depth(inode);
3187
3188 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003189 * consistent leaf must not be empty;
3190 * this situation is possible, though, _during_ tree modification;
Alex Tomasa86c6182006-10-11 01:21:03 -07003191 * this is why assert can't be put in ext4_ext_find_extent()
3192 */
3193 BUG_ON(path[depth].p_ext == NULL && depth != 0);
Amit Arora56055d32007-07-17 21:42:38 -04003194 eh = path[depth].p_hdr;
Alex Tomasa86c6182006-10-11 01:21:03 -07003195
Avantika Mathur7e028972006-12-06 20:41:33 -08003196 ex = path[depth].p_ext;
3197 if (ex) {
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003198 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
Alex Tomasf65e6fb2006-10-11 01:21:05 -07003199 ext4_fsblk_t ee_start = ext_pblock(ex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04003200 unsigned short ee_len;
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07003201
3202 /*
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07003203 * Uninitialized extents are treated as holes, except that
Amit Arora56055d32007-07-17 21:42:38 -04003204 * we split out initialized portions during a write.
Suparna Bhattacharya471d4012006-10-11 01:21:06 -07003205 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04003206 ee_len = ext4_ext_get_actual_len(ex);
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003207 /* if found extent covers block, simply return it */
Dave Kleikamp8c55e202007-05-24 13:04:54 -04003208 if (iblock >= ee_block && iblock < ee_block + ee_len) {
Alex Tomasa86c6182006-10-11 01:21:03 -07003209 newblock = iblock - ee_block + ee_start;
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003210 /* number of remaining blocks in the extent */
Alex Tomasa86c6182006-10-11 01:21:03 -07003211 allocated = ee_len - (iblock - ee_block);
Mingming84fe3be2009-09-01 08:44:37 -04003212 ext_debug("%u fit into %u:%d -> %llu\n", iblock,
Alex Tomasa86c6182006-10-11 01:21:03 -07003213 ee_block, ee_len, newblock);
Amit Arora56055d32007-07-17 21:42:38 -04003214
Amit Aroraa2df2a62007-07-17 21:42:41 -04003215 /* Do not put uninitialized extent in the cache */
Amit Arora56055d32007-07-17 21:42:38 -04003216 if (!ext4_ext_is_uninitialized(ex)) {
Amit Aroraa2df2a62007-07-17 21:42:41 -04003217 ext4_ext_put_in_cache(inode, ee_block,
3218 ee_len, ee_start,
3219 EXT4_EXT_CACHE_EXTENT);
Amit Arora56055d32007-07-17 21:42:38 -04003220 goto out;
3221 }
Mingming Cao00314622009-09-28 15:49:08 -04003222 ret = ext4_ext_handle_uninitialized_extents(handle,
3223 inode, iblock, max_blocks, path,
3224 flags, allocated, bh_result, newblock);
3225 return ret;
Alex Tomasa86c6182006-10-11 01:21:03 -07003226 }
3227 }
3228
3229 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003230 * requested block isn't allocated yet;
Alex Tomasa86c6182006-10-11 01:21:03 -07003231 * we couldn't try to create block if create flag is zero
3232 */
Theodore Ts'oc2177052009-05-14 00:58:52 -04003233 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
Amit Arora56055d32007-07-17 21:42:38 -04003234 /*
3235 * put just found gap into cache to speed up
3236 * subsequent requests
3237 */
Alex Tomasa86c6182006-10-11 01:21:03 -07003238 ext4_ext_put_gap_in_cache(inode, path, iblock);
3239 goto out2;
3240 }
3241 /*
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04003242 * Okay, we need to do block allocation.
Andrew Morton63f57932006-10-11 01:21:24 -07003243 */
Alex Tomasa86c6182006-10-11 01:21:03 -07003244
Alex Tomasc9de5602008-01-29 00:19:52 -05003245 /* find neighbour allocated blocks */
3246 ar.lleft = iblock;
3247 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
3248 if (err)
3249 goto out2;
3250 ar.lright = iblock;
3251 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
3252 if (err)
3253 goto out2;
Amit Arora25d14f92007-05-24 13:04:13 -04003254
Amit Arora749269f2007-07-18 09:02:56 -04003255 /*
3256 * See if request is beyond maximum number of blocks we can have in
3257 * a single extent. For an initialized extent this limit is
3258 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
3259 * EXT_UNINIT_MAX_LEN.
3260 */
3261 if (max_blocks > EXT_INIT_MAX_LEN &&
Theodore Ts'oc2177052009-05-14 00:58:52 -04003262 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
Amit Arora749269f2007-07-18 09:02:56 -04003263 max_blocks = EXT_INIT_MAX_LEN;
3264 else if (max_blocks > EXT_UNINIT_MAX_LEN &&
Theodore Ts'oc2177052009-05-14 00:58:52 -04003265 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
Amit Arora749269f2007-07-18 09:02:56 -04003266 max_blocks = EXT_UNINIT_MAX_LEN;
3267
Amit Arora25d14f92007-05-24 13:04:13 -04003268 /* Check if we can really insert (iblock)::(iblock+max_blocks) extent */
3269 newex.ee_block = cpu_to_le32(iblock);
3270 newex.ee_len = cpu_to_le16(max_blocks);
3271 err = ext4_ext_check_overlap(inode, &newex, path);
3272 if (err)
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05003273 allocated = ext4_ext_get_actual_len(&newex);
Amit Arora25d14f92007-05-24 13:04:13 -04003274 else
3275 allocated = max_blocks;
Alex Tomasc9de5602008-01-29 00:19:52 -05003276
3277 /* allocate new block */
3278 ar.inode = inode;
3279 ar.goal = ext4_ext_find_goal(inode, path, iblock);
3280 ar.logical = iblock;
3281 ar.len = allocated;
3282 if (S_ISREG(inode->i_mode))
3283 ar.flags = EXT4_MB_HINT_DATA;
3284 else
3285 /* disable in-core preallocation for non-regular files */
3286 ar.flags = 0;
3287 newblock = ext4_mb_new_blocks(handle, &ar, &err);
Alex Tomasa86c6182006-10-11 01:21:03 -07003288 if (!newblock)
3289 goto out2;
Mingming84fe3be2009-09-01 08:44:37 -04003290 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003291 ar.goal, newblock, allocated);
Alex Tomasa86c6182006-10-11 01:21:03 -07003292
3293 /* try to insert new extent into found leaf and return */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07003294 ext4_ext_store_pblock(&newex, newblock);
Alex Tomasc9de5602008-01-29 00:19:52 -05003295 newex.ee_len = cpu_to_le16(ar.len);
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003296 /* Mark uninitialized */
3297 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
Amit Aroraa2df2a62007-07-17 21:42:41 -04003298 ext4_ext_mark_uninitialized(&newex);
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003299 /*
3300 * io_end structure was created for every async
3301 * direct IO write to the middle of the file.
3302 * To avoid unecessary convertion for every aio dio rewrite
3303 * to the mid of file, here we flag the IO that is really
3304 * need the convertion.
Mingming5f524952009-11-10 10:48:04 -05003305 * For non asycn direct IO case, flag the inode state
3306 * that we need to perform convertion when IO is done.
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003307 */
Mingming5f524952009-11-10 10:48:04 -05003308 if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) {
3309 if (io)
3310 io->flag = DIO_AIO_UNWRITTEN;
3311 else
3312 EXT4_I(inode)->i_state |=
3313 EXT4_STATE_DIO_UNWRITTEN;;
3314 }
Mingming Cao8d5d02e2009-09-28 15:48:29 -04003315 }
Mingming Cao00314622009-09-28 15:49:08 -04003316 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
Alex Tomas315054f2007-05-24 13:04:25 -04003317 if (err) {
3318 /* free data blocks we just allocated */
Alex Tomasc9de5602008-01-29 00:19:52 -05003319 /* not a good idea to call discard here directly,
3320 * but otherwise we'd need to call it every free() */
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04003321 ext4_discard_preallocations(inode);
Alex Tomas315054f2007-05-24 13:04:25 -04003322 ext4_free_blocks(handle, inode, ext_pblock(&newex),
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05003323 ext4_ext_get_actual_len(&newex), 0);
Alex Tomasa86c6182006-10-11 01:21:03 -07003324 goto out2;
Alex Tomas315054f2007-05-24 13:04:25 -04003325 }
Alex Tomasa86c6182006-10-11 01:21:03 -07003326
Alex Tomasa86c6182006-10-11 01:21:03 -07003327 /* previous routine could use block we allocated */
Alex Tomasf65e6fb2006-10-11 01:21:05 -07003328 newblock = ext_pblock(&newex);
Aneesh Kumar K.Vb939e372008-01-28 23:58:27 -05003329 allocated = ext4_ext_get_actual_len(&newex);
Eric Sandeen953e6222008-07-11 19:27:31 -04003330 set_buffer_new(bh_result);
Alex Tomasa86c6182006-10-11 01:21:03 -07003331
Amit Aroraa2df2a62007-07-17 21:42:41 -04003332 /* Cache only when it is _not_ an uninitialized extent */
Theodore Ts'oc2177052009-05-14 00:58:52 -04003333 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0)
Amit Aroraa2df2a62007-07-17 21:42:41 -04003334 ext4_ext_put_in_cache(inode, iblock, allocated, newblock,
3335 EXT4_EXT_CACHE_EXTENT);
Alex Tomasa86c6182006-10-11 01:21:03 -07003336out:
3337 if (allocated > max_blocks)
3338 allocated = max_blocks;
3339 ext4_ext_show_leaf(inode, path);
Eric Sandeen953e6222008-07-11 19:27:31 -04003340 set_buffer_mapped(bh_result);
Alex Tomasa86c6182006-10-11 01:21:03 -07003341 bh_result->b_bdev = inode->i_sb->s_bdev;
3342 bh_result->b_blocknr = newblock;
3343out2:
3344 if (path) {
3345 ext4_ext_drop_refs(path);
3346 kfree(path);
3347 }
Alex Tomasa86c6182006-10-11 01:21:03 -07003348 return err ? err : allocated;
3349}
3350
Jan Karacf108bc2008-07-11 19:27:31 -04003351void ext4_ext_truncate(struct inode *inode)
Alex Tomasa86c6182006-10-11 01:21:03 -07003352{
3353 struct address_space *mapping = inode->i_mapping;
3354 struct super_block *sb = inode->i_sb;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003355 ext4_lblk_t last_block;
Alex Tomasa86c6182006-10-11 01:21:03 -07003356 handle_t *handle;
3357 int err = 0;
3358
3359 /*
3360 * probably first extent we're gonna free will be last in block
3361 */
Mingming Caof3bd1f32008-08-19 22:16:03 -04003362 err = ext4_writepage_trans_blocks(inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07003363 handle = ext4_journal_start(inode, err);
Jan Karacf108bc2008-07-11 19:27:31 -04003364 if (IS_ERR(handle))
Alex Tomasa86c6182006-10-11 01:21:03 -07003365 return;
Alex Tomasa86c6182006-10-11 01:21:03 -07003366
Jan Karacf108bc2008-07-11 19:27:31 -04003367 if (inode->i_size & (sb->s_blocksize - 1))
3368 ext4_block_truncate_page(handle, mapping, inode->i_size);
Alex Tomasa86c6182006-10-11 01:21:03 -07003369
Jan Kara9ddfc3d2008-07-11 19:27:31 -04003370 if (ext4_orphan_add(handle, inode))
3371 goto out_stop;
3372
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -05003373 down_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07003374 ext4_ext_invalidate_cache(inode);
3375
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04003376 ext4_discard_preallocations(inode);
Alex Tomasc9de5602008-01-29 00:19:52 -05003377
Alex Tomasa86c6182006-10-11 01:21:03 -07003378 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003379 * TODO: optimization is possible here.
3380 * Probably we need not scan at all,
3381 * because page truncation is enough.
Alex Tomasa86c6182006-10-11 01:21:03 -07003382 */
Alex Tomasa86c6182006-10-11 01:21:03 -07003383
3384 /* we have to know where to truncate from in crash case */
3385 EXT4_I(inode)->i_disksize = inode->i_size;
3386 ext4_mark_inode_dirty(handle, inode);
3387
3388 last_block = (inode->i_size + sb->s_blocksize - 1)
3389 >> EXT4_BLOCK_SIZE_BITS(sb);
3390 err = ext4_ext_remove_space(inode, last_block);
3391
3392 /* In a multi-transaction truncate, we only make the final
Amit Arora56055d32007-07-17 21:42:38 -04003393 * transaction synchronous.
3394 */
Alex Tomasa86c6182006-10-11 01:21:03 -07003395 if (IS_SYNC(inode))
Frank Mayhar03901312009-01-07 00:06:22 -05003396 ext4_handle_sync(handle);
Alex Tomasa86c6182006-10-11 01:21:03 -07003397
3398out_stop:
Jan Kara9ddfc3d2008-07-11 19:27:31 -04003399 up_write(&EXT4_I(inode)->i_data_sem);
Alex Tomasa86c6182006-10-11 01:21:03 -07003400 /*
Randy Dunlapd0d856e2006-10-11 01:21:07 -07003401 * If this was a simple ftruncate() and the file will remain alive,
Alex Tomasa86c6182006-10-11 01:21:03 -07003402 * then we need to clear up the orphan record which we created above.
3403 * However, if this was a real unlink then we were called by
3404 * ext4_delete_inode(), and we allow that function to clean up the
3405 * orphan info for us.
3406 */
3407 if (inode->i_nlink)
3408 ext4_orphan_del(handle, inode);
3409
Solofo Ramangalahyef737722008-04-29 22:00:41 -04003410 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3411 ext4_mark_inode_dirty(handle, inode);
Alex Tomasa86c6182006-10-11 01:21:03 -07003412 ext4_journal_stop(handle);
3413}
3414
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003415static void ext4_falloc_update_inode(struct inode *inode,
3416 int mode, loff_t new_size, int update_ctime)
3417{
3418 struct timespec now;
3419
3420 if (update_ctime) {
3421 now = current_fs_time(inode->i_sb);
3422 if (!timespec_equal(&inode->i_ctime, &now))
3423 inode->i_ctime = now;
3424 }
3425 /*
3426 * Update only when preallocation was requested beyond
3427 * the file size.
3428 */
Aneesh Kumar K.Vcf17fea2008-09-13 13:06:18 -04003429 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3430 if (new_size > i_size_read(inode))
3431 i_size_write(inode, new_size);
3432 if (new_size > EXT4_I(inode)->i_disksize)
3433 ext4_update_i_disksize(inode, new_size);
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003434 }
3435
3436}
3437
Amit Aroraa2df2a62007-07-17 21:42:41 -04003438/*
3439 * preallocate space for a file. This implements ext4's fallocate inode
3440 * operation, which gets called from sys_fallocate system call.
3441 * For block-mapped files, posix_fallocate should fall back to the method
3442 * of writing zeroes to the required new blocks (the same behavior which is
3443 * expected for file systems which do not support fallocate() system call).
3444 */
3445long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
3446{
3447 handle_t *handle;
Aneesh Kumar K.V725d26d2008-01-28 23:58:27 -05003448 ext4_lblk_t block;
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003449 loff_t new_size;
Theodore Ts'o498e5f22008-11-05 00:14:04 -05003450 unsigned int max_blocks;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003451 int ret = 0;
3452 int ret2 = 0;
3453 int retries = 0;
3454 struct buffer_head map_bh;
3455 unsigned int credits, blkbits = inode->i_blkbits;
3456
3457 /*
3458 * currently supporting (pre)allocate mode for extent-based
3459 * files _only_
3460 */
3461 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3462 return -EOPNOTSUPP;
3463
3464 /* preallocation to directories is currently not supported */
3465 if (S_ISDIR(inode->i_mode))
3466 return -ENODEV;
3467
3468 block = offset >> blkbits;
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003469 /*
3470 * We can't just convert len to max_blocks because
3471 * If blocksize = 4096 offset = 3072 and len = 2048
3472 */
Amit Aroraa2df2a62007-07-17 21:42:41 -04003473 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003474 - block;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003475 /*
Mingming Caof3bd1f32008-08-19 22:16:03 -04003476 * credits to insert 1 extent into extent tree
Amit Aroraa2df2a62007-07-17 21:42:41 -04003477 */
Mingming Caof3bd1f32008-08-19 22:16:03 -04003478 credits = ext4_chunk_trans_blocks(inode, max_blocks);
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05003479 mutex_lock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04003480retry:
3481 while (ret >= 0 && ret < max_blocks) {
3482 block = block + ret;
3483 max_blocks = max_blocks - ret;
3484 handle = ext4_journal_start(inode, credits);
3485 if (IS_ERR(handle)) {
3486 ret = PTR_ERR(handle);
3487 break;
3488 }
Aneesh Kumar K.V79ffab32009-05-13 15:13:42 -04003489 map_bh.b_state = 0;
Theodore Ts'o12b7ac12009-05-14 00:57:44 -04003490 ret = ext4_get_blocks(handle, inode, block,
3491 max_blocks, &map_bh,
Theodore Ts'oc2177052009-05-14 00:58:52 -04003492 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT);
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05003493 if (ret <= 0) {
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05003494#ifdef EXT4FS_DEBUG
3495 WARN_ON(ret <= 0);
3496 printk(KERN_ERR "%s: ext4_ext_get_blocks "
3497 "returned error inode#%lu, block=%u, "
Thadeu Lima de Souza Cascardo9fd97842009-01-26 19:26:26 -05003498 "max_blocks=%u", __func__,
Aneesh Kumar K.V221879c2008-01-28 23:58:27 -05003499 inode->i_ino, block, max_blocks);
Aneesh Kumar K.V2c986152008-02-25 15:41:35 -05003500#endif
Amit Aroraa2df2a62007-07-17 21:42:41 -04003501 ext4_mark_inode_dirty(handle, inode);
3502 ret2 = ext4_journal_stop(handle);
3503 break;
3504 }
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003505 if ((block + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
3506 blkbits) >> blkbits))
3507 new_size = offset + len;
3508 else
3509 new_size = (block + ret) << blkbits;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003510
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003511 ext4_falloc_update_inode(inode, mode, new_size,
3512 buffer_new(&map_bh));
Amit Aroraa2df2a62007-07-17 21:42:41 -04003513 ext4_mark_inode_dirty(handle, inode);
3514 ret2 = ext4_journal_stop(handle);
3515 if (ret2)
3516 break;
3517 }
Aneesh Kumar K.Vfd287842008-04-29 08:11:12 -04003518 if (ret == -ENOSPC &&
3519 ext4_should_retry_alloc(inode->i_sb, &retries)) {
3520 ret = 0;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003521 goto retry;
Amit Aroraa2df2a62007-07-17 21:42:41 -04003522 }
Aneesh Kumar K.V55bd7252008-02-15 12:47:21 -05003523 mutex_unlock(&inode->i_mutex);
Amit Aroraa2df2a62007-07-17 21:42:41 -04003524 return ret > 0 ? ret2 : ret;
3525}
Eric Sandeen6873fa02008-10-07 00:46:36 -04003526
3527/*
Mingming Cao00314622009-09-28 15:49:08 -04003528 * This function convert a range of blocks to written extents
3529 * The caller of this function will pass the start offset and the size.
3530 * all unwritten extents within this range will be converted to
3531 * written extents.
3532 *
3533 * This function is called from the direct IO end io call back
3534 * function, to convert the fallocated extents after IO is completed.
Mingming109f5562009-11-10 10:48:08 -05003535 * Returns 0 on success.
Mingming Cao00314622009-09-28 15:49:08 -04003536 */
3537int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
3538 loff_t len)
3539{
3540 handle_t *handle;
3541 ext4_lblk_t block;
3542 unsigned int max_blocks;
3543 int ret = 0;
3544 int ret2 = 0;
3545 struct buffer_head map_bh;
3546 unsigned int credits, blkbits = inode->i_blkbits;
3547
3548 block = offset >> blkbits;
3549 /*
3550 * We can't just convert len to max_blocks because
3551 * If blocksize = 4096 offset = 3072 and len = 2048
3552 */
3553 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
3554 - block;
3555 /*
3556 * credits to insert 1 extent into extent tree
3557 */
3558 credits = ext4_chunk_trans_blocks(inode, max_blocks);
3559 while (ret >= 0 && ret < max_blocks) {
3560 block = block + ret;
3561 max_blocks = max_blocks - ret;
3562 handle = ext4_journal_start(inode, credits);
3563 if (IS_ERR(handle)) {
3564 ret = PTR_ERR(handle);
3565 break;
3566 }
3567 map_bh.b_state = 0;
3568 ret = ext4_get_blocks(handle, inode, block,
3569 max_blocks, &map_bh,
3570 EXT4_GET_BLOCKS_DIO_CONVERT_EXT);
3571 if (ret <= 0) {
3572 WARN_ON(ret <= 0);
3573 printk(KERN_ERR "%s: ext4_ext_get_blocks "
3574 "returned error inode#%lu, block=%u, "
3575 "max_blocks=%u", __func__,
3576 inode->i_ino, block, max_blocks);
3577 }
3578 ext4_mark_inode_dirty(handle, inode);
3579 ret2 = ext4_journal_stop(handle);
3580 if (ret <= 0 || ret2 )
3581 break;
3582 }
3583 return ret > 0 ? ret2 : ret;
3584}
3585/*
Eric Sandeen6873fa02008-10-07 00:46:36 -04003586 * Callback function called for each extent to gather FIEMAP information.
3587 */
Aneesh Kumar K.V3a06d772008-11-22 15:04:59 -05003588static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path,
Eric Sandeen6873fa02008-10-07 00:46:36 -04003589 struct ext4_ext_cache *newex, struct ext4_extent *ex,
3590 void *data)
3591{
3592 struct fiemap_extent_info *fieinfo = data;
Eric Sandeenc9877b22009-05-01 23:32:06 -04003593 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
Eric Sandeen6873fa02008-10-07 00:46:36 -04003594 __u64 logical;
3595 __u64 physical;
3596 __u64 length;
3597 __u32 flags = 0;
3598 int error;
3599
3600 logical = (__u64)newex->ec_block << blksize_bits;
3601
3602 if (newex->ec_type == EXT4_EXT_CACHE_GAP) {
3603 pgoff_t offset;
3604 struct page *page;
3605 struct buffer_head *bh = NULL;
3606
3607 offset = logical >> PAGE_SHIFT;
3608 page = find_get_page(inode->i_mapping, offset);
3609 if (!page || !page_has_buffers(page))
3610 return EXT_CONTINUE;
3611
3612 bh = page_buffers(page);
3613
3614 if (!bh)
3615 return EXT_CONTINUE;
3616
3617 if (buffer_delay(bh)) {
3618 flags |= FIEMAP_EXTENT_DELALLOC;
3619 page_cache_release(page);
3620 } else {
3621 page_cache_release(page);
3622 return EXT_CONTINUE;
3623 }
3624 }
3625
3626 physical = (__u64)newex->ec_start << blksize_bits;
3627 length = (__u64)newex->ec_len << blksize_bits;
3628
3629 if (ex && ext4_ext_is_uninitialized(ex))
3630 flags |= FIEMAP_EXTENT_UNWRITTEN;
3631
3632 /*
3633 * If this extent reaches EXT_MAX_BLOCK, it must be last.
3634 *
3635 * Or if ext4_ext_next_allocated_block is EXT_MAX_BLOCK,
3636 * this also indicates no more allocated blocks.
3637 *
3638 * XXX this might miss a single-block extent at EXT_MAX_BLOCK
3639 */
Eric Sandeenc9877b22009-05-01 23:32:06 -04003640 if (ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK ||
Theodore Ts'oeefd7f02009-05-02 19:05:37 -04003641 newex->ec_block + newex->ec_len - 1 == EXT_MAX_BLOCK) {
3642 loff_t size = i_size_read(inode);
3643 loff_t bs = EXT4_BLOCK_SIZE(inode->i_sb);
3644
Eric Sandeen6873fa02008-10-07 00:46:36 -04003645 flags |= FIEMAP_EXTENT_LAST;
Theodore Ts'oeefd7f02009-05-02 19:05:37 -04003646 if ((flags & FIEMAP_EXTENT_DELALLOC) &&
3647 logical+length > size)
3648 length = (size - logical + bs - 1) & ~(bs-1);
3649 }
Eric Sandeen6873fa02008-10-07 00:46:36 -04003650
3651 error = fiemap_fill_next_extent(fieinfo, logical, physical,
3652 length, flags);
3653 if (error < 0)
3654 return error;
3655 if (error == 1)
3656 return EXT_BREAK;
3657
3658 return EXT_CONTINUE;
3659}
3660
3661/* fiemap flags we can handle specified here */
3662#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
3663
Aneesh Kumar K.V3a06d772008-11-22 15:04:59 -05003664static int ext4_xattr_fiemap(struct inode *inode,
3665 struct fiemap_extent_info *fieinfo)
Eric Sandeen6873fa02008-10-07 00:46:36 -04003666{
3667 __u64 physical = 0;
3668 __u64 length;
3669 __u32 flags = FIEMAP_EXTENT_LAST;
3670 int blockbits = inode->i_sb->s_blocksize_bits;
3671 int error = 0;
3672
3673 /* in-inode? */
3674 if (EXT4_I(inode)->i_state & EXT4_STATE_XATTR) {
3675 struct ext4_iloc iloc;
3676 int offset; /* offset of xattr in inode */
3677
3678 error = ext4_get_inode_loc(inode, &iloc);
3679 if (error)
3680 return error;
3681 physical = iloc.bh->b_blocknr << blockbits;
3682 offset = EXT4_GOOD_OLD_INODE_SIZE +
3683 EXT4_I(inode)->i_extra_isize;
3684 physical += offset;
3685 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
3686 flags |= FIEMAP_EXTENT_DATA_INLINE;
3687 } else { /* external block */
3688 physical = EXT4_I(inode)->i_file_acl << blockbits;
3689 length = inode->i_sb->s_blocksize;
3690 }
3691
3692 if (physical)
3693 error = fiemap_fill_next_extent(fieinfo, 0, physical,
3694 length, flags);
3695 return (error < 0 ? error : 0);
3696}
3697
3698int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3699 __u64 start, __u64 len)
3700{
3701 ext4_lblk_t start_blk;
3702 ext4_lblk_t len_blks;
3703 int error = 0;
3704
3705 /* fallback to generic here if not in extents fmt */
3706 if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
3707 return generic_block_fiemap(inode, fieinfo, start, len,
3708 ext4_get_block);
3709
3710 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
3711 return -EBADR;
3712
3713 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
3714 error = ext4_xattr_fiemap(inode, fieinfo);
3715 } else {
3716 start_blk = start >> inode->i_sb->s_blocksize_bits;
3717 len_blks = len >> inode->i_sb->s_blocksize_bits;
3718
3719 /*
3720 * Walk the extent tree gathering extent information.
3721 * ext4_ext_fiemap_cb will push extents back to user.
3722 */
Theodore Ts'o0568c512009-05-17 23:31:23 -04003723 down_read(&EXT4_I(inode)->i_data_sem);
Eric Sandeen6873fa02008-10-07 00:46:36 -04003724 error = ext4_ext_walk_space(inode, start_blk, len_blks,
3725 ext4_ext_fiemap_cb, fieinfo);
Theodore Ts'o0568c512009-05-17 23:31:23 -04003726 up_read(&EXT4_I(inode)->i_data_sem);
Eric Sandeen6873fa02008-10-07 00:46:36 -04003727 }
3728
3729 return error;
3730}
3731