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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext2/inode.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@dcs.ed.ac.uk), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
21 *
22 * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
23 */
24
25#include <linux/smp_lock.h>
26#include <linux/time.h>
27#include <linux/highuid.h>
28#include <linux/pagemap.h>
29#include <linux/quotaops.h>
30#include <linux/module.h>
31#include <linux/writeback.h>
32#include <linux/buffer_head.h>
33#include <linux/mpage.h>
Josef Bacik68c9d702008-10-03 17:32:43 -040034#include <linux/fiemap.h>
Duane Griffin8d6d0c42008-12-19 20:47:13 +000035#include <linux/namei.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include "ext2.h"
37#include "acl.h"
Carsten Otte6d791252005-06-23 22:05:26 -070038#include "xip.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40MODULE_AUTHOR("Remy Card and others");
41MODULE_DESCRIPTION("Second Extended Filesystem");
42MODULE_LICENSE("GPL");
43
Christoph Hellwiga9185b42010-03-05 09:21:37 +010044static int __ext2_write_inode(struct inode *inode, int do_sync);
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046/*
47 * Test whether an inode is a fast symlink.
48 */
49static inline int ext2_inode_is_fast_symlink(struct inode *inode)
50{
51 int ea_blocks = EXT2_I(inode)->i_file_acl ?
52 (inode->i_sb->s_blocksize >> 9) : 0;
53
54 return (S_ISLNK(inode->i_mode) &&
55 inode->i_blocks - ea_blocks == 0);
56}
57
58/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * Called at the last iput() if i_nlink is zero.
60 */
61void ext2_delete_inode (struct inode * inode)
62{
Christoph Hellwig907f4552010-03-03 09:05:06 -050063 if (!is_bad_inode(inode))
Christoph Hellwig871a2932010-03-03 09:05:07 -050064 dquot_initialize(inode);
Mark Fashehfef26652005-09-09 13:01:31 -070065 truncate_inode_pages(&inode->i_data, 0);
66
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 if (is_bad_inode(inode))
68 goto no_delete;
69 EXT2_I(inode)->i_dtime = get_seconds();
70 mark_inode_dirty(inode);
Christoph Hellwiga9185b42010-03-05 09:21:37 +010071 __ext2_write_inode(inode, inode_needs_sync(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 inode->i_size = 0;
74 if (inode->i_blocks)
75 ext2_truncate (inode);
76 ext2_free_inode (inode);
77
78 return;
79no_delete:
80 clear_inode(inode); /* We must guarantee clearing of inode... */
81}
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083typedef struct {
84 __le32 *p;
85 __le32 key;
86 struct buffer_head *bh;
87} Indirect;
88
89static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
90{
91 p->key = *(p->p = v);
92 p->bh = bh;
93}
94
95static inline int verify_chain(Indirect *from, Indirect *to)
96{
97 while (from <= to && from->key == *from->p)
98 from++;
99 return (from > to);
100}
101
102/**
103 * ext2_block_to_path - parse the block number into array of offsets
104 * @inode: inode in question (we are only interested in its superblock)
105 * @i_block: block number to be parsed
106 * @offsets: array to store the offsets in
107 * @boundary: set this non-zero if the referred-to block is likely to be
108 * followed (on disk) by an indirect block.
109 * To store the locations of file's data ext2 uses a data structure common
110 * for UNIX filesystems - tree of pointers anchored in the inode, with
111 * data blocks at leaves and indirect blocks in intermediate nodes.
112 * This function translates the block number into path in that tree -
113 * return value is the path length and @offsets[n] is the offset of
114 * pointer to (n+1)th node in the nth one. If @block is out of range
115 * (negative or too large) warning is printed and zero returned.
116 *
117 * Note: function doesn't find node addresses, so no IO is needed. All
118 * we need to know is the capacity of indirect blocks (taken from the
119 * inode->i_sb).
120 */
121
122/*
123 * Portability note: the last comparison (check that we fit into triple
124 * indirect block) is spelled differently, because otherwise on an
125 * architecture with 32-bit longs and 8Kb pages we might get into trouble
126 * if our filesystem had 8Kb blocks. We might use long long, but that would
127 * kill us on x86. Oh, well, at least the sign propagation does not matter -
128 * i_block would have to be negative in the very beginning, so we would not
129 * get there at all.
130 */
131
132static int ext2_block_to_path(struct inode *inode,
133 long i_block, int offsets[4], int *boundary)
134{
135 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
136 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
137 const long direct_blocks = EXT2_NDIR_BLOCKS,
138 indirect_blocks = ptrs,
139 double_blocks = (1 << (ptrs_bits * 2));
140 int n = 0;
141 int final = 0;
142
143 if (i_block < 0) {
Alexey Fisher2314b072009-11-19 19:12:51 +0100144 ext2_msg(inode->i_sb, KERN_WARNING,
145 "warning: %s: block < 0", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 } else if (i_block < direct_blocks) {
147 offsets[n++] = i_block;
148 final = direct_blocks;
149 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
150 offsets[n++] = EXT2_IND_BLOCK;
151 offsets[n++] = i_block;
152 final = ptrs;
153 } else if ((i_block -= indirect_blocks) < double_blocks) {
154 offsets[n++] = EXT2_DIND_BLOCK;
155 offsets[n++] = i_block >> ptrs_bits;
156 offsets[n++] = i_block & (ptrs - 1);
157 final = ptrs;
158 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
159 offsets[n++] = EXT2_TIND_BLOCK;
160 offsets[n++] = i_block >> (ptrs_bits * 2);
161 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
162 offsets[n++] = i_block & (ptrs - 1);
163 final = ptrs;
164 } else {
Alexey Fisher2314b072009-11-19 19:12:51 +0100165 ext2_msg(inode->i_sb, KERN_WARNING,
166 "warning: %s: block is too big", __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 }
168 if (boundary)
Martin J. Bligha686cd82007-10-16 23:30:46 -0700169 *boundary = final - 1 - (i_block & (ptrs - 1));
170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 return n;
172}
173
174/**
175 * ext2_get_branch - read the chain of indirect blocks leading to data
176 * @inode: inode in question
177 * @depth: depth of the chain (1 - direct pointer, etc.)
178 * @offsets: offsets of pointers in inode/indirect blocks
179 * @chain: place to store the result
180 * @err: here we store the error value
181 *
182 * Function fills the array of triples <key, p, bh> and returns %NULL
183 * if everything went OK or the pointer to the last filled triple
184 * (incomplete one) otherwise. Upon the return chain[i].key contains
185 * the number of (i+1)-th block in the chain (as it is stored in memory,
186 * i.e. little-endian 32-bit), chain[i].p contains the address of that
187 * number (it points into struct inode for i==0 and into the bh->b_data
188 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
189 * block for i>0 and NULL for i==0. In other words, it holds the block
190 * numbers of the chain, addresses they were taken from (and where we can
191 * verify that chain did not change) and buffer_heads hosting these
192 * numbers.
193 *
194 * Function stops when it stumbles upon zero pointer (absent block)
195 * (pointer to last triple returned, *@err == 0)
196 * or when it gets an IO error reading an indirect block
197 * (ditto, *@err == -EIO)
198 * or when it notices that chain had been changed while it was reading
199 * (ditto, *@err == -EAGAIN)
200 * or when it reads all @depth-1 indirect blocks successfully and finds
201 * the whole chain, all way to the data (returns %NULL, *err == 0).
202 */
203static Indirect *ext2_get_branch(struct inode *inode,
204 int depth,
205 int *offsets,
206 Indirect chain[4],
207 int *err)
208{
209 struct super_block *sb = inode->i_sb;
210 Indirect *p = chain;
211 struct buffer_head *bh;
212
213 *err = 0;
214 /* i_data is not going away, no lock needed */
215 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
216 if (!p->key)
217 goto no_block;
218 while (--depth) {
219 bh = sb_bread(sb, le32_to_cpu(p->key));
220 if (!bh)
221 goto failure;
222 read_lock(&EXT2_I(inode)->i_meta_lock);
223 if (!verify_chain(chain, p))
224 goto changed;
225 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
226 read_unlock(&EXT2_I(inode)->i_meta_lock);
227 if (!p->key)
228 goto no_block;
229 }
230 return NULL;
231
232changed:
233 read_unlock(&EXT2_I(inode)->i_meta_lock);
234 brelse(bh);
235 *err = -EAGAIN;
236 goto no_block;
237failure:
238 *err = -EIO;
239no_block:
240 return p;
241}
242
243/**
244 * ext2_find_near - find a place for allocation with sufficient locality
245 * @inode: owner
246 * @ind: descriptor of indirect block.
247 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000248 * This function returns the preferred place for block allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 * It is used when heuristic for sequential allocation fails.
250 * Rules are:
251 * + if there is a block to the left of our position - allocate near it.
252 * + if pointer will live in indirect block - allocate near that block.
253 * + if pointer will live in inode - allocate in the same cylinder group.
254 *
255 * In the latter case we colour the starting block by the callers PID to
256 * prevent it from clashing with concurrent allocations for a different inode
257 * in the same block group. The PID is used here so that functionally related
258 * files will be close-by on-disk.
259 *
260 * Caller must make sure that @ind is valid and will stay that way.
261 */
262
Akinobu Mita4c8b3122008-04-28 02:16:02 -0700263static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
265 struct ext2_inode_info *ei = EXT2_I(inode);
266 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
267 __le32 *p;
Akinobu Mita4c8b3122008-04-28 02:16:02 -0700268 ext2_fsblk_t bg_start;
269 ext2_fsblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271 /* Try to find previous block */
272 for (p = ind->p - 1; p >= start; p--)
273 if (*p)
274 return le32_to_cpu(*p);
275
276 /* No such thing, so let's try location of indirect block */
277 if (ind->bh)
278 return ind->bh->b_blocknr;
279
280 /*
281 * It is going to be refered from inode itself? OK, just put it into
282 * the same cylinder group then.
283 */
Akinobu Mita24097d12008-04-28 02:16:01 -0700284 bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 colour = (current->pid % 16) *
286 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
287 return bg_start + colour;
288}
289
290/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000291 * ext2_find_goal - find a preferred place for allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 * @inode: owner
293 * @block: block we want
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 * @partial: pointer to the last triple within a chain
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 *
Martin J. Bligha686cd82007-10-16 23:30:46 -0700296 * Returns preferred place for a block (the goal).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 */
298
Akinobu Mita4c8b3122008-04-28 02:16:02 -0700299static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
300 Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
Martin J. Bligha686cd82007-10-16 23:30:46 -0700302 struct ext2_block_alloc_info *block_i;
303
304 block_i = EXT2_I(inode)->i_block_alloc_info;
305
306 /*
307 * try the heuristic for sequential allocation,
308 * failing that at least try to get decent locality.
309 */
310 if (block_i && (block == block_i->last_alloc_logical_block + 1)
311 && (block_i->last_alloc_physical_block != 0)) {
312 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 }
Martin J. Bligha686cd82007-10-16 23:30:46 -0700314
315 return ext2_find_near(inode, partial);
316}
317
318/**
319 * ext2_blks_to_allocate: Look up the block map and count the number
320 * of direct blocks need to be allocated for the given branch.
321 *
322 * @branch: chain of indirect blocks
323 * @k: number of blocks need for indirect blocks
324 * @blks: number of data blocks to be mapped.
325 * @blocks_to_boundary: the offset in the indirect block
326 *
327 * return the total number of blocks to be allocate, including the
328 * direct and indirect blocks.
329 */
330static int
331ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
332 int blocks_to_boundary)
333{
334 unsigned long count = 0;
335
336 /*
337 * Simple case, [t,d]Indirect block(s) has not allocated yet
338 * then it's clear blocks on that path have not allocated
339 */
340 if (k > 0) {
341 /* right now don't hanel cross boundary allocation */
342 if (blks < blocks_to_boundary + 1)
343 count += blks;
344 else
345 count += blocks_to_boundary + 1;
346 return count;
347 }
348
349 count++;
350 while (count < blks && count <= blocks_to_boundary
351 && le32_to_cpu(*(branch[0].p + count)) == 0) {
352 count++;
353 }
354 return count;
355}
356
357/**
358 * ext2_alloc_blocks: multiple allocate blocks needed for a branch
359 * @indirect_blks: the number of blocks need to allocate for indirect
360 * blocks
361 *
362 * @new_blocks: on return it will store the new block numbers for
363 * the indirect blocks(if needed) and the first direct block,
364 * @blks: on return it will store the total number of allocated
365 * direct blocks
366 */
367static int ext2_alloc_blocks(struct inode *inode,
368 ext2_fsblk_t goal, int indirect_blks, int blks,
369 ext2_fsblk_t new_blocks[4], int *err)
370{
371 int target, i;
372 unsigned long count = 0;
373 int index = 0;
374 ext2_fsblk_t current_block = 0;
375 int ret = 0;
376
377 /*
378 * Here we try to allocate the requested multiple blocks at once,
379 * on a best-effort basis.
380 * To build a branch, we should allocate blocks for
381 * the indirect blocks(if not allocated yet), and at least
382 * the first direct block of this branch. That's the
383 * minimum number of blocks need to allocate(required)
384 */
385 target = blks + indirect_blks;
386
387 while (1) {
388 count = target;
389 /* allocating blocks for indirect blocks and direct blocks */
390 current_block = ext2_new_blocks(inode,goal,&count,err);
391 if (*err)
392 goto failed_out;
393
394 target -= count;
395 /* allocate blocks for indirect blocks */
396 while (index < indirect_blks && count) {
397 new_blocks[index++] = current_block++;
398 count--;
399 }
400
401 if (count > 0)
402 break;
403 }
404
405 /* save the new block number for the first direct block */
406 new_blocks[index] = current_block;
407
408 /* total number of blocks allocated for direct blocks */
409 ret = count;
410 *err = 0;
411 return ret;
412failed_out:
413 for (i = 0; i <index; i++)
414 ext2_free_blocks(inode, new_blocks[i], 1);
415 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416}
417
418/**
419 * ext2_alloc_branch - allocate and set up a chain of blocks.
420 * @inode: owner
421 * @num: depth of the chain (number of blocks to allocate)
422 * @offsets: offsets (in the blocks) to store the pointers to next.
423 * @branch: place to store the chain in.
424 *
425 * This function allocates @num blocks, zeroes out all but the last one,
426 * links them into chain and (if we are synchronous) writes them to disk.
427 * In other words, it prepares a branch that can be spliced onto the
428 * inode. It stores the information about that chain in the branch[], in
429 * the same format as ext2_get_branch() would do. We are calling it after
430 * we had read the existing part of chain and partial points to the last
431 * triple of that (one with zero ->key). Upon the exit we have the same
432 * picture as after the successful ext2_get_block(), excpet that in one
433 * place chain is disconnected - *branch->p is still zero (we did not
434 * set the last link), but branch->key contains the number that should
435 * be placed into *branch->p to fill that gap.
436 *
437 * If allocation fails we free all blocks we've allocated (and forget
438 * their buffer_heads) and return the error value the from failed
439 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
440 * as described above and return 0.
441 */
442
443static int ext2_alloc_branch(struct inode *inode,
Martin J. Bligha686cd82007-10-16 23:30:46 -0700444 int indirect_blks, int *blks, ext2_fsblk_t goal,
445 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446{
447 int blocksize = inode->i_sb->s_blocksize;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700448 int i, n = 0;
449 int err = 0;
450 struct buffer_head *bh;
451 int num;
452 ext2_fsblk_t new_blocks[4];
453 ext2_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
Martin J. Bligha686cd82007-10-16 23:30:46 -0700455 num = ext2_alloc_blocks(inode, goal, indirect_blks,
456 *blks, new_blocks, &err);
457 if (err)
458 return err;
459
460 branch[0].key = cpu_to_le32(new_blocks[0]);
461 /*
462 * metadata blocks and data blocks are allocated.
463 */
464 for (n = 1; n <= indirect_blks; n++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 /*
Martin J. Bligha686cd82007-10-16 23:30:46 -0700466 * Get buffer_head for parent block, zero it out
467 * and set the pointer to new one, then send
468 * parent to disk.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 */
Martin J. Bligha686cd82007-10-16 23:30:46 -0700470 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
471 branch[n].bh = bh;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 lock_buffer(bh);
473 memset(bh->b_data, 0, blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 branch[n].p = (__le32 *) bh->b_data + offsets[n];
Martin J. Bligha686cd82007-10-16 23:30:46 -0700475 branch[n].key = cpu_to_le32(new_blocks[n]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 *branch[n].p = branch[n].key;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700477 if ( n == indirect_blks) {
478 current_block = new_blocks[n];
479 /*
480 * End of chain, update the last new metablock of
481 * the chain to point to the new allocated
482 * data blocks numbers
483 */
484 for (i=1; i < num; i++)
485 *(branch[n].p + i) = cpu_to_le32(++current_block);
486 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 set_buffer_uptodate(bh);
488 unlock_buffer(bh);
489 mark_buffer_dirty_inode(bh, inode);
490 /* We used to sync bh here if IS_SYNC(inode).
Jan Karaa2a735a2009-08-18 17:54:11 +0200491 * But we now rely upon generic_write_sync()
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 * and b_inode_buffers. But not for directories.
493 */
494 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
495 sync_dirty_buffer(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 }
Martin J. Bligha686cd82007-10-16 23:30:46 -0700497 *blks = num;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 return err;
499}
500
501/**
Martin J. Bligha686cd82007-10-16 23:30:46 -0700502 * ext2_splice_branch - splice the allocated branch onto inode.
503 * @inode: owner
504 * @block: (logical) number of block we are adding
Martin J. Bligha686cd82007-10-16 23:30:46 -0700505 * @where: location of missing link
506 * @num: number of indirect blocks we are adding
507 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 *
Martin J. Bligha686cd82007-10-16 23:30:46 -0700509 * This function fills the missing link and does all housekeeping needed in
510 * inode (->i_blocks, etc.). In case of success we end up with the full
511 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 */
Martin J. Bligha686cd82007-10-16 23:30:46 -0700513static void ext2_splice_branch(struct inode *inode,
514 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 int i;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700517 struct ext2_block_alloc_info *block_i;
518 ext2_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519
Martin J. Bligha686cd82007-10-16 23:30:46 -0700520 block_i = EXT2_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
Martin J. Bligha686cd82007-10-16 23:30:46 -0700522 /* XXX LOCKING probably should have i_meta_lock ?*/
Linus Torvalds1da177e2005-04-16 15:20:36 -0700523 /* That's it */
524
525 *where->p = where->key;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526
Martin J. Bligha686cd82007-10-16 23:30:46 -0700527 /*
528 * Update the host buffer_head or inode to point to more just allocated
529 * direct blocks blocks
530 */
531 if (num == 0 && blks > 1) {
532 current_block = le32_to_cpu(where->key) + 1;
533 for (i = 1; i < blks; i++)
534 *(where->p + i ) = cpu_to_le32(current_block++);
535 }
536
537 /*
538 * update the most recently allocated logical & physical block
539 * in i_block_alloc_info, to assist find the proper goal block for next
540 * allocation
541 */
542 if (block_i) {
543 block_i->last_alloc_logical_block = block + blks - 1;
544 block_i->last_alloc_physical_block =
545 le32_to_cpu(where[num].key) + blks - 1;
546 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547
548 /* We are done with atomic stuff, now do the rest of housekeeping */
549
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 /* had we spliced it onto indirect block? */
551 if (where->bh)
552 mark_buffer_dirty_inode(where->bh, inode);
553
Martin J. Bligha686cd82007-10-16 23:30:46 -0700554 inode->i_ctime = CURRENT_TIME_SEC;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 mark_inode_dirty(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556}
557
558/*
559 * Allocation strategy is simple: if we have to allocate something, we will
560 * have to go the whole way to leaf. So let's do it before attaching anything
561 * to tree, set linkage between the newborn blocks, write them if sync is
562 * required, recheck the path, free and repeat if check fails, otherwise
563 * set the last missing link (that will protect us from any truncate-generated
564 * removals - all blocks on the path are immune now) and possibly force the
565 * write on the parent block.
566 * That has a nice additional property: no special recovery from the failed
567 * allocations is needed - we simply release blocks and do not touch anything
568 * reachable from inode.
Martin J. Bligha686cd82007-10-16 23:30:46 -0700569 *
570 * `handle' can be NULL if create == 0.
571 *
Martin J. Bligha686cd82007-10-16 23:30:46 -0700572 * return > 0, # of blocks mapped or allocated.
573 * return = 0, if plain lookup failed.
574 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 */
Martin J. Bligha686cd82007-10-16 23:30:46 -0700576static int ext2_get_blocks(struct inode *inode,
577 sector_t iblock, unsigned long maxblocks,
578 struct buffer_head *bh_result,
579 int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580{
581 int err = -EIO;
582 int offsets[4];
583 Indirect chain[4];
584 Indirect *partial;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700585 ext2_fsblk_t goal;
586 int indirect_blks;
587 int blocks_to_boundary = 0;
588 int depth;
589 struct ext2_inode_info *ei = EXT2_I(inode);
590 int count = 0;
591 ext2_fsblk_t first_block = 0;
592
593 depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
595 if (depth == 0)
Martin J. Bligha686cd82007-10-16 23:30:46 -0700596 return (err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597
Jan Kara316cb4ef32009-04-13 14:40:14 -0700598 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 /* Simplest case - block found, no allocation needed */
600 if (!partial) {
Martin J. Bligha686cd82007-10-16 23:30:46 -0700601 first_block = le32_to_cpu(chain[depth - 1].key);
602 clear_buffer_new(bh_result); /* What's this do? */
603 count++;
604 /*map more blocks*/
605 while (count < maxblocks && count <= blocks_to_boundary) {
606 ext2_fsblk_t blk;
607
Jan Kara316cb4ef32009-04-13 14:40:14 -0700608 if (!verify_chain(chain, chain + depth - 1)) {
Martin J. Bligha686cd82007-10-16 23:30:46 -0700609 /*
610 * Indirect block might be removed by
611 * truncate while we were reading it.
612 * Handling of that case: forget what we've
613 * got now, go to reread.
614 */
Jan Kara316cb4ef32009-04-13 14:40:14 -0700615 err = -EAGAIN;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700616 count = 0;
Jan Kara316cb4ef32009-04-13 14:40:14 -0700617 break;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700618 }
619 blk = le32_to_cpu(*(chain[depth-1].p + count));
620 if (blk == first_block + count)
621 count++;
622 else
623 break;
624 }
Jan Kara316cb4ef32009-04-13 14:40:14 -0700625 if (err != -EAGAIN)
626 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 }
628
629 /* Next simple case - plain lookup or failed read of indirect block */
Martin J. Bligha686cd82007-10-16 23:30:46 -0700630 if (!create || err == -EIO)
631 goto cleanup;
632
633 mutex_lock(&ei->truncate_mutex);
Jan Kara316cb4ef32009-04-13 14:40:14 -0700634 /*
635 * If the indirect block is missing while we are reading
636 * the chain(ext3_get_branch() returns -EAGAIN err), or
637 * if the chain has been changed after we grab the semaphore,
638 * (either because another process truncated this branch, or
639 * another get_block allocated this branch) re-grab the chain to see if
640 * the request block has been allocated or not.
641 *
642 * Since we already block the truncate/other get_block
643 * at this point, we will have the current copy of the chain when we
644 * splice the branch into the tree.
645 */
646 if (err == -EAGAIN || !verify_chain(chain, partial)) {
647 while (partial > chain) {
648 brelse(partial->bh);
649 partial--;
650 }
651 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
652 if (!partial) {
653 count++;
654 mutex_unlock(&ei->truncate_mutex);
655 if (err)
656 goto cleanup;
657 clear_buffer_new(bh_result);
658 goto got_it;
659 }
660 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
662 /*
Martin J. Bligha686cd82007-10-16 23:30:46 -0700663 * Okay, we need to do block allocation. Lazily initialize the block
664 * allocation info here if necessary
665 */
666 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
667 ext2_init_block_alloc_info(inode);
668
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800669 goal = ext2_find_goal(inode, iblock, partial);
Martin J. Bligha686cd82007-10-16 23:30:46 -0700670
671 /* the number of blocks need to allocate for [d,t]indirect blocks */
672 indirect_blks = (chain + depth) - partial - 1;
673 /*
674 * Next look up the indirect map to count the totoal number of
675 * direct blocks to allocate for this branch.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 */
Martin J. Bligha686cd82007-10-16 23:30:46 -0700677 count = ext2_blks_to_allocate(partial, indirect_blks,
678 maxblocks, blocks_to_boundary);
679 /*
680 * XXX ???? Block out ext2_truncate while we alter the tree
681 */
682 err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
683 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
Martin J. Bligha686cd82007-10-16 23:30:46 -0700685 if (err) {
686 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 goto cleanup;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700688 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689
Carsten Otte6d791252005-06-23 22:05:26 -0700690 if (ext2_use_xip(inode->i_sb)) {
691 /*
692 * we need to clear the block
693 */
694 err = ext2_clear_xip_target (inode,
695 le32_to_cpu(chain[depth-1].key));
Martin J. Bligha686cd82007-10-16 23:30:46 -0700696 if (err) {
697 mutex_unlock(&ei->truncate_mutex);
Carsten Otte6d791252005-06-23 22:05:26 -0700698 goto cleanup;
Martin J. Bligha686cd82007-10-16 23:30:46 -0700699 }
Carsten Otte6d791252005-06-23 22:05:26 -0700700 }
701
Martin J. Bligha686cd82007-10-16 23:30:46 -0700702 ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
703 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 set_buffer_new(bh_result);
Martin J. Bligha686cd82007-10-16 23:30:46 -0700705got_it:
706 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
707 if (count > blocks_to_boundary)
708 set_buffer_boundary(bh_result);
709 err = count;
710 /* Clean up and exit */
711 partial = chain + depth - 1; /* the whole chain */
712cleanup:
713 while (partial > chain) {
714 brelse(partial->bh);
715 partial--;
716 }
717 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718}
719
Martin J. Bligha686cd82007-10-16 23:30:46 -0700720int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
721{
722 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
723 int ret = ext2_get_blocks(inode, iblock, max_blocks,
724 bh_result, create);
725 if (ret > 0) {
726 bh_result->b_size = (ret << inode->i_blkbits);
727 ret = 0;
728 }
729 return ret;
730
731}
732
Josef Bacik68c9d702008-10-03 17:32:43 -0400733int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
734 u64 start, u64 len)
735{
736 return generic_block_fiemap(inode, fieinfo, start, len,
737 ext2_get_block);
738}
739
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740static int ext2_writepage(struct page *page, struct writeback_control *wbc)
741{
742 return block_write_full_page(page, ext2_get_block, wbc);
743}
744
745static int ext2_readpage(struct file *file, struct page *page)
746{
747 return mpage_readpage(page, ext2_get_block);
748}
749
750static int
751ext2_readpages(struct file *file, struct address_space *mapping,
752 struct list_head *pages, unsigned nr_pages)
753{
754 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
755}
756
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700757int __ext2_write_begin(struct file *file, struct address_space *mapping,
758 loff_t pos, unsigned len, unsigned flags,
759 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760{
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700761 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
762 ext2_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763}
764
765static int
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700766ext2_write_begin(struct file *file, struct address_space *mapping,
767 loff_t pos, unsigned len, unsigned flags,
768 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769{
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700770 *pagep = NULL;
771 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772}
773
Nick Piggin03158cd2007-10-16 01:25:25 -0700774static int
775ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
776 loff_t pos, unsigned len, unsigned flags,
777 struct page **pagep, void **fsdata)
778{
779 /*
780 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework
781 * directory handling code to pass around offsets rather than struct
782 * pages in order to make this work easily.
783 */
784 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
785 ext2_get_block);
786}
787
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788static int ext2_nobh_writepage(struct page *page,
789 struct writeback_control *wbc)
790{
791 return nobh_writepage(page, ext2_get_block, wbc);
792}
793
794static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
795{
796 return generic_block_bmap(mapping,block,ext2_get_block);
797}
798
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799static ssize_t
800ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
801 loff_t offset, unsigned long nr_segs)
802{
803 struct file *file = iocb->ki_filp;
804 struct inode *inode = file->f_mapping->host;
805
806 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800807 offset, nr_segs, ext2_get_block, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808}
809
810static int
811ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
812{
813 return mpage_writepages(mapping, wbc, ext2_get_block);
814}
815
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700816const struct address_space_operations ext2_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 .readpage = ext2_readpage,
818 .readpages = ext2_readpages,
819 .writepage = ext2_writepage,
820 .sync_page = block_sync_page,
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700821 .write_begin = ext2_write_begin,
822 .write_end = generic_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 .bmap = ext2_bmap,
824 .direct_IO = ext2_direct_IO,
825 .writepages = ext2_writepages,
Christoph Lametere965f962006-02-01 03:05:41 -0800826 .migratepage = buffer_migrate_page,
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -0700827 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +0200828 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829};
830
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700831const struct address_space_operations ext2_aops_xip = {
Carsten Otte6d791252005-06-23 22:05:26 -0700832 .bmap = ext2_bmap,
Nick Piggin70688e42008-04-28 02:13:02 -0700833 .get_xip_mem = ext2_get_xip_mem,
Carsten Otte6d791252005-06-23 22:05:26 -0700834};
835
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700836const struct address_space_operations ext2_nobh_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 .readpage = ext2_readpage,
838 .readpages = ext2_readpages,
839 .writepage = ext2_nobh_writepage,
840 .sync_page = block_sync_page,
Nick Piggin03158cd2007-10-16 01:25:25 -0700841 .write_begin = ext2_nobh_write_begin,
842 .write_end = nobh_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 .bmap = ext2_bmap,
844 .direct_IO = ext2_direct_IO,
845 .writepages = ext2_writepages,
Christoph Lametere965f962006-02-01 03:05:41 -0800846 .migratepage = buffer_migrate_page,
Andi Kleenaa261f52009-09-16 11:50:16 +0200847 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848};
849
850/*
851 * Probably it should be a library function... search for first non-zero word
852 * or memcmp with zero_page, whatever is better for particular architecture.
853 * Linus?
854 */
855static inline int all_zeroes(__le32 *p, __le32 *q)
856{
857 while (p < q)
858 if (*p++)
859 return 0;
860 return 1;
861}
862
863/**
864 * ext2_find_shared - find the indirect blocks for partial truncation.
865 * @inode: inode in question
866 * @depth: depth of the affected branch
867 * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
868 * @chain: place to store the pointers to partial indirect blocks
869 * @top: place to the (detached) top of branch
870 *
871 * This is a helper function used by ext2_truncate().
872 *
873 * When we do truncate() we may have to clean the ends of several indirect
874 * blocks but leave the blocks themselves alive. Block is partially
875 * truncated if some data below the new i_size is refered from it (and
876 * it is on the path to the first completely truncated data block, indeed).
877 * We have to free the top of that path along with everything to the right
878 * of the path. Since no allocation past the truncation point is possible
879 * until ext2_truncate() finishes, we may safely do the latter, but top
880 * of branch may require special attention - pageout below the truncation
881 * point might try to populate it.
882 *
883 * We atomically detach the top of branch from the tree, store the block
884 * number of its root in *@top, pointers to buffer_heads of partially
885 * truncated blocks - in @chain[].bh and pointers to their last elements
886 * that should not be removed - in @chain[].p. Return value is the pointer
887 * to last filled element of @chain.
888 *
889 * The work left to caller to do the actual freeing of subtrees:
890 * a) free the subtree starting from *@top
891 * b) free the subtrees whose roots are stored in
892 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
893 * c) free the subtrees growing from the inode past the @chain[0].p
894 * (no partially truncated stuff there).
895 */
896
897static Indirect *ext2_find_shared(struct inode *inode,
898 int depth,
899 int offsets[4],
900 Indirect chain[4],
901 __le32 *top)
902{
903 Indirect *partial, *p;
904 int k, err;
905
906 *top = 0;
907 for (k = depth; k > 1 && !offsets[k-1]; k--)
908 ;
909 partial = ext2_get_branch(inode, k, offsets, chain, &err);
910 if (!partial)
911 partial = chain + k-1;
912 /*
913 * If the branch acquired continuation since we've looked at it -
914 * fine, it should all survive and (new) top doesn't belong to us.
915 */
916 write_lock(&EXT2_I(inode)->i_meta_lock);
917 if (!partial->key && *partial->p) {
918 write_unlock(&EXT2_I(inode)->i_meta_lock);
919 goto no_top;
920 }
921 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
922 ;
923 /*
924 * OK, we've found the last block that must survive. The rest of our
925 * branch should be detached before unlocking. However, if that rest
926 * of branch is all ours and does not grow immediately from the inode
927 * it's easier to cheat and just decrement partial->p.
928 */
929 if (p == chain + k - 1 && p > chain) {
930 p->p--;
931 } else {
932 *top = *p->p;
933 *p->p = 0;
934 }
935 write_unlock(&EXT2_I(inode)->i_meta_lock);
936
937 while(partial > p)
938 {
939 brelse(partial->bh);
940 partial--;
941 }
942no_top:
943 return partial;
944}
945
946/**
947 * ext2_free_data - free a list of data blocks
948 * @inode: inode we are dealing with
949 * @p: array of block numbers
950 * @q: points immediately past the end of array
951 *
952 * We are freeing all blocks refered from that array (numbers are
953 * stored as little-endian 32-bit) and updating @inode->i_blocks
954 * appropriately.
955 */
956static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
957{
958 unsigned long block_to_free = 0, count = 0;
959 unsigned long nr;
960
961 for ( ; p < q ; p++) {
962 nr = le32_to_cpu(*p);
963 if (nr) {
964 *p = 0;
965 /* accumulate blocks to free if they're contiguous */
966 if (count == 0)
967 goto free_this;
968 else if (block_to_free == nr - count)
969 count++;
970 else {
971 mark_inode_dirty(inode);
972 ext2_free_blocks (inode, block_to_free, count);
973 free_this:
974 block_to_free = nr;
975 count = 1;
976 }
977 }
978 }
979 if (count > 0) {
980 mark_inode_dirty(inode);
981 ext2_free_blocks (inode, block_to_free, count);
982 }
983}
984
985/**
986 * ext2_free_branches - free an array of branches
987 * @inode: inode we are dealing with
988 * @p: array of block numbers
989 * @q: pointer immediately past the end of array
990 * @depth: depth of the branches to free
991 *
992 * We are freeing all blocks refered from these branches (numbers are
993 * stored as little-endian 32-bit) and updating @inode->i_blocks
994 * appropriately.
995 */
996static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
997{
998 struct buffer_head * bh;
999 unsigned long nr;
1000
1001 if (depth--) {
1002 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1003 for ( ; p < q ; p++) {
1004 nr = le32_to_cpu(*p);
1005 if (!nr)
1006 continue;
1007 *p = 0;
1008 bh = sb_bread(inode->i_sb, nr);
1009 /*
1010 * A read failure? Report error and clear slot
1011 * (should be rare).
1012 */
1013 if (!bh) {
1014 ext2_error(inode->i_sb, "ext2_free_branches",
1015 "Read failure, inode=%ld, block=%ld",
1016 inode->i_ino, nr);
1017 continue;
1018 }
1019 ext2_free_branches(inode,
1020 (__le32*)bh->b_data,
1021 (__le32*)bh->b_data + addr_per_block,
1022 depth);
1023 bforget(bh);
1024 ext2_free_blocks(inode, nr, 1);
1025 mark_inode_dirty(inode);
1026 }
1027 } else
1028 ext2_free_data(inode, p, q);
1029}
1030
Martin J. Bligha686cd82007-10-16 23:30:46 -07001031void ext2_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001032{
1033 __le32 *i_data = EXT2_I(inode)->i_data;
Martin J. Bligha686cd82007-10-16 23:30:46 -07001034 struct ext2_inode_info *ei = EXT2_I(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1036 int offsets[4];
1037 Indirect chain[4];
1038 Indirect *partial;
1039 __le32 nr = 0;
1040 int n;
1041 long iblock;
1042 unsigned blocksize;
1043
1044 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1045 S_ISLNK(inode->i_mode)))
1046 return;
1047 if (ext2_inode_is_fast_symlink(inode))
1048 return;
1049 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1050 return;
1051
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 blocksize = inode->i_sb->s_blocksize;
1053 iblock = (inode->i_size + blocksize-1)
1054 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
1055
Carsten Otte6d791252005-06-23 22:05:26 -07001056 if (mapping_is_xip(inode->i_mapping))
1057 xip_truncate_page(inode->i_mapping, inode->i_size);
1058 else if (test_opt(inode->i_sb, NOBH))
Nick Piggin03158cd2007-10-16 01:25:25 -07001059 nobh_truncate_page(inode->i_mapping,
1060 inode->i_size, ext2_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 else
1062 block_truncate_page(inode->i_mapping,
1063 inode->i_size, ext2_get_block);
1064
1065 n = ext2_block_to_path(inode, iblock, offsets, NULL);
1066 if (n == 0)
1067 return;
1068
Martin J. Bligha686cd82007-10-16 23:30:46 -07001069 /*
1070 * From here we block out all ext2_get_block() callers who want to
1071 * modify the block allocation tree.
1072 */
1073 mutex_lock(&ei->truncate_mutex);
1074
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 if (n == 1) {
1076 ext2_free_data(inode, i_data+offsets[0],
1077 i_data + EXT2_NDIR_BLOCKS);
1078 goto do_indirects;
1079 }
1080
1081 partial = ext2_find_shared(inode, n, offsets, chain, &nr);
1082 /* Kill the top of shared branch (already detached) */
1083 if (nr) {
1084 if (partial == chain)
1085 mark_inode_dirty(inode);
1086 else
1087 mark_buffer_dirty_inode(partial->bh, inode);
1088 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
1089 }
1090 /* Clear the ends of indirect blocks on the shared branch */
1091 while (partial > chain) {
1092 ext2_free_branches(inode,
1093 partial->p + 1,
1094 (__le32*)partial->bh->b_data+addr_per_block,
1095 (chain+n-1) - partial);
1096 mark_buffer_dirty_inode(partial->bh, inode);
1097 brelse (partial->bh);
1098 partial--;
1099 }
1100do_indirects:
1101 /* Kill the remaining (whole) subtrees */
1102 switch (offsets[0]) {
1103 default:
1104 nr = i_data[EXT2_IND_BLOCK];
1105 if (nr) {
1106 i_data[EXT2_IND_BLOCK] = 0;
1107 mark_inode_dirty(inode);
1108 ext2_free_branches(inode, &nr, &nr+1, 1);
1109 }
1110 case EXT2_IND_BLOCK:
1111 nr = i_data[EXT2_DIND_BLOCK];
1112 if (nr) {
1113 i_data[EXT2_DIND_BLOCK] = 0;
1114 mark_inode_dirty(inode);
1115 ext2_free_branches(inode, &nr, &nr+1, 2);
1116 }
1117 case EXT2_DIND_BLOCK:
1118 nr = i_data[EXT2_TIND_BLOCK];
1119 if (nr) {
1120 i_data[EXT2_TIND_BLOCK] = 0;
1121 mark_inode_dirty(inode);
1122 ext2_free_branches(inode, &nr, &nr+1, 3);
1123 }
1124 case EXT2_TIND_BLOCK:
1125 ;
1126 }
Martin J. Bligha686cd82007-10-16 23:30:46 -07001127
1128 ext2_discard_reservation(inode);
1129
1130 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
1132 if (inode_needs_sync(inode)) {
1133 sync_mapping_buffers(inode->i_mapping);
1134 ext2_sync_inode (inode);
1135 } else {
1136 mark_inode_dirty(inode);
1137 }
1138}
1139
1140static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1141 struct buffer_head **p)
1142{
1143 struct buffer_head * bh;
1144 unsigned long block_group;
1145 unsigned long block;
1146 unsigned long offset;
1147 struct ext2_group_desc * gdp;
1148
1149 *p = NULL;
1150 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1151 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1152 goto Einval;
1153
1154 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
Eric Sandeenef2fb672007-10-16 23:26:30 -07001155 gdp = ext2_get_group_desc(sb, block_group, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 if (!gdp)
1157 goto Egdp;
1158 /*
1159 * Figure out the offset within the block group inode table
1160 */
1161 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1162 block = le32_to_cpu(gdp->bg_inode_table) +
1163 (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1164 if (!(bh = sb_bread(sb, block)))
1165 goto Eio;
1166
1167 *p = bh;
1168 offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1169 return (struct ext2_inode *) (bh->b_data + offset);
1170
1171Einval:
1172 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1173 (unsigned long) ino);
1174 return ERR_PTR(-EINVAL);
1175Eio:
1176 ext2_error(sb, "ext2_get_inode",
1177 "unable to read inode block - inode=%lu, block=%lu",
1178 (unsigned long) ino, block);
1179Egdp:
1180 return ERR_PTR(-EIO);
1181}
1182
1183void ext2_set_inode_flags(struct inode *inode)
1184{
1185 unsigned int flags = EXT2_I(inode)->i_flags;
1186
1187 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
1188 if (flags & EXT2_SYNC_FL)
1189 inode->i_flags |= S_SYNC;
1190 if (flags & EXT2_APPEND_FL)
1191 inode->i_flags |= S_APPEND;
1192 if (flags & EXT2_IMMUTABLE_FL)
1193 inode->i_flags |= S_IMMUTABLE;
1194 if (flags & EXT2_NOATIME_FL)
1195 inode->i_flags |= S_NOATIME;
1196 if (flags & EXT2_DIRSYNC_FL)
1197 inode->i_flags |= S_DIRSYNC;
1198}
1199
Jan Kara4f99ed62007-05-08 00:31:04 -07001200/* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
1201void ext2_get_inode_flags(struct ext2_inode_info *ei)
1202{
1203 unsigned int flags = ei->vfs_inode.i_flags;
1204
1205 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
1206 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
1207 if (flags & S_SYNC)
1208 ei->i_flags |= EXT2_SYNC_FL;
1209 if (flags & S_APPEND)
1210 ei->i_flags |= EXT2_APPEND_FL;
1211 if (flags & S_IMMUTABLE)
1212 ei->i_flags |= EXT2_IMMUTABLE_FL;
1213 if (flags & S_NOATIME)
1214 ei->i_flags |= EXT2_NOATIME_FL;
1215 if (flags & S_DIRSYNC)
1216 ei->i_flags |= EXT2_DIRSYNC_FL;
1217}
1218
David Howells52fcf702008-02-07 00:15:35 -08001219struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001220{
David Howells52fcf702008-02-07 00:15:35 -08001221 struct ext2_inode_info *ei;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 struct buffer_head * bh;
David Howells52fcf702008-02-07 00:15:35 -08001223 struct ext2_inode *raw_inode;
1224 struct inode *inode;
1225 long ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001226 int n;
1227
David Howells52fcf702008-02-07 00:15:35 -08001228 inode = iget_locked(sb, ino);
1229 if (!inode)
1230 return ERR_PTR(-ENOMEM);
1231 if (!(inode->i_state & I_NEW))
1232 return inode;
1233
1234 ei = EXT2_I(inode);
Martin J. Bligha686cd82007-10-16 23:30:46 -07001235 ei->i_block_alloc_info = NULL;
1236
David Howells52fcf702008-02-07 00:15:35 -08001237 raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1238 if (IS_ERR(raw_inode)) {
1239 ret = PTR_ERR(raw_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 goto bad_inode;
David Howells52fcf702008-02-07 00:15:35 -08001241 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001242
1243 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1244 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1245 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1246 if (!(test_opt (inode->i_sb, NO_UID32))) {
1247 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1248 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1249 }
1250 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
1251 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07001252 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
1253 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
1254 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1256 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1257 /* We now have enough fields to check if the inode was active or not.
1258 * This is needed because nfsd might try to access dead inodes
1259 * the test is that same one that e2fsck uses
1260 * NeilBrown 1999oct15
1261 */
1262 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
1263 /* this inode is deleted */
1264 brelse (bh);
David Howells52fcf702008-02-07 00:15:35 -08001265 ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001266 goto bad_inode;
1267 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001268 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1269 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1270 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1271 ei->i_frag_no = raw_inode->i_frag;
1272 ei->i_frag_size = raw_inode->i_fsize;
1273 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1274 ei->i_dir_acl = 0;
1275 if (S_ISREG(inode->i_mode))
1276 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1277 else
1278 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1279 ei->i_dtime = 0;
1280 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1281 ei->i_state = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1283 ei->i_dir_start_lookup = 0;
1284
1285 /*
1286 * NOTE! The in-memory inode i_data array is in little-endian order
1287 * even on big-endian machines: we do NOT byteswap the block numbers!
1288 */
1289 for (n = 0; n < EXT2_N_BLOCKS; n++)
1290 ei->i_data[n] = raw_inode->i_block[n];
1291
1292 if (S_ISREG(inode->i_mode)) {
1293 inode->i_op = &ext2_file_inode_operations;
Carsten Otte6d791252005-06-23 22:05:26 -07001294 if (ext2_use_xip(inode->i_sb)) {
1295 inode->i_mapping->a_ops = &ext2_aops_xip;
1296 inode->i_fop = &ext2_xip_file_operations;
1297 } else if (test_opt(inode->i_sb, NOBH)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298 inode->i_mapping->a_ops = &ext2_nobh_aops;
Carsten Otte6d791252005-06-23 22:05:26 -07001299 inode->i_fop = &ext2_file_operations;
1300 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301 inode->i_mapping->a_ops = &ext2_aops;
Carsten Otte6d791252005-06-23 22:05:26 -07001302 inode->i_fop = &ext2_file_operations;
1303 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 } else if (S_ISDIR(inode->i_mode)) {
1305 inode->i_op = &ext2_dir_inode_operations;
1306 inode->i_fop = &ext2_dir_operations;
1307 if (test_opt(inode->i_sb, NOBH))
1308 inode->i_mapping->a_ops = &ext2_nobh_aops;
1309 else
1310 inode->i_mapping->a_ops = &ext2_aops;
1311 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffin8d6d0c42008-12-19 20:47:13 +00001312 if (ext2_inode_is_fast_symlink(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 inode->i_op = &ext2_fast_symlink_inode_operations;
Duane Griffin8d6d0c42008-12-19 20:47:13 +00001314 nd_terminate_link(ei->i_data, inode->i_size,
1315 sizeof(ei->i_data) - 1);
1316 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 inode->i_op = &ext2_symlink_inode_operations;
1318 if (test_opt(inode->i_sb, NOBH))
1319 inode->i_mapping->a_ops = &ext2_nobh_aops;
1320 else
1321 inode->i_mapping->a_ops = &ext2_aops;
1322 }
1323 } else {
1324 inode->i_op = &ext2_special_inode_operations;
1325 if (raw_inode->i_block[0])
1326 init_special_inode(inode, inode->i_mode,
1327 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1328 else
1329 init_special_inode(inode, inode->i_mode,
1330 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1331 }
1332 brelse (bh);
1333 ext2_set_inode_flags(inode);
David Howells52fcf702008-02-07 00:15:35 -08001334 unlock_new_inode(inode);
1335 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336
1337bad_inode:
David Howells52fcf702008-02-07 00:15:35 -08001338 iget_failed(inode);
1339 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001340}
1341
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001342static int __ext2_write_inode(struct inode *inode, int do_sync)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343{
1344 struct ext2_inode_info *ei = EXT2_I(inode);
1345 struct super_block *sb = inode->i_sb;
1346 ino_t ino = inode->i_ino;
1347 uid_t uid = inode->i_uid;
1348 gid_t gid = inode->i_gid;
1349 struct buffer_head * bh;
1350 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1351 int n;
1352 int err = 0;
1353
1354 if (IS_ERR(raw_inode))
1355 return -EIO;
1356
1357 /* For fields not not tracking in the in-memory inode,
1358 * initialise them to zero for new inodes. */
1359 if (ei->i_state & EXT2_STATE_NEW)
1360 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1361
Jan Kara4f99ed62007-05-08 00:31:04 -07001362 ext2_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001363 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1364 if (!(test_opt(sb, NO_UID32))) {
1365 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1366 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1367/*
1368 * Fix up interoperability with old kernels. Otherwise, old inodes get
1369 * re-used with the upper 16 bits of the uid/gid intact
1370 */
1371 if (!ei->i_dtime) {
1372 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1373 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1374 } else {
1375 raw_inode->i_uid_high = 0;
1376 raw_inode->i_gid_high = 0;
1377 }
1378 } else {
1379 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1380 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1381 raw_inode->i_uid_high = 0;
1382 raw_inode->i_gid_high = 0;
1383 }
1384 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1385 raw_inode->i_size = cpu_to_le32(inode->i_size);
1386 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1387 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1388 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1389
1390 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1391 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1392 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1393 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1394 raw_inode->i_frag = ei->i_frag_no;
1395 raw_inode->i_fsize = ei->i_frag_size;
1396 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1397 if (!S_ISREG(inode->i_mode))
1398 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1399 else {
1400 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1401 if (inode->i_size > 0x7fffffffULL) {
1402 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1403 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1404 EXT2_SB(sb)->s_es->s_rev_level ==
1405 cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1406 /* If this is the first large file
1407 * created, add a flag to the superblock.
1408 */
1409 lock_kernel();
1410 ext2_update_dynamic_rev(sb);
1411 EXT2_SET_RO_COMPAT_FEATURE(sb,
1412 EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1413 unlock_kernel();
1414 ext2_write_super(sb);
1415 }
1416 }
1417 }
1418
1419 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1420 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1421 if (old_valid_dev(inode->i_rdev)) {
1422 raw_inode->i_block[0] =
1423 cpu_to_le32(old_encode_dev(inode->i_rdev));
1424 raw_inode->i_block[1] = 0;
1425 } else {
1426 raw_inode->i_block[0] = 0;
1427 raw_inode->i_block[1] =
1428 cpu_to_le32(new_encode_dev(inode->i_rdev));
1429 raw_inode->i_block[2] = 0;
1430 }
1431 } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1432 raw_inode->i_block[n] = ei->i_data[n];
1433 mark_buffer_dirty(bh);
1434 if (do_sync) {
1435 sync_dirty_buffer(bh);
1436 if (buffer_req(bh) && !buffer_uptodate(bh)) {
1437 printk ("IO error syncing ext2 inode [%s:%08lx]\n",
1438 sb->s_id, (unsigned long) ino);
1439 err = -EIO;
1440 }
1441 }
1442 ei->i_state &= ~EXT2_STATE_NEW;
1443 brelse (bh);
1444 return err;
1445}
1446
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001447int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
1448{
1449 return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
1450}
1451
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452int ext2_sync_inode(struct inode *inode)
1453{
1454 struct writeback_control wbc = {
1455 .sync_mode = WB_SYNC_ALL,
1456 .nr_to_write = 0, /* sys_fsync did this */
1457 };
1458 return sync_inode(inode, &wbc);
1459}
1460
1461int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
1462{
1463 struct inode *inode = dentry->d_inode;
1464 int error;
1465
1466 error = inode_change_ok(inode, iattr);
1467 if (error)
1468 return error;
Christoph Hellwig907f4552010-03-03 09:05:06 -05001469
1470 if (iattr->ia_valid & ATTR_SIZE)
Christoph Hellwig871a2932010-03-03 09:05:07 -05001471 dquot_initialize(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
1473 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
Christoph Hellwigb43fa822010-03-03 09:05:03 -05001474 error = dquot_transfer(inode, iattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001475 if (error)
1476 return error;
1477 }
1478 error = inode_setattr(inode, iattr);
1479 if (!error && (iattr->ia_valid & ATTR_MODE))
1480 error = ext2_acl_chmod(inode);
1481 return error;
1482}