blob: bb98f52f4ea4341af0013157275130c4745d654f [file] [log] [blame]
Chris Mason6cbd5572007-06-12 09:07:21 -04001/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
Chris Mason39279cc2007-06-12 06:35:45 -040019#include <linux/fs.h>
20#include <linux/pagemap.h>
21#include <linux/highmem.h>
22#include <linux/time.h>
23#include <linux/init.h>
24#include <linux/string.h>
25#include <linux/smp_lock.h>
26#include <linux/backing-dev.h>
27#include <linux/mpage.h>
28#include <linux/swap.h>
29#include <linux/writeback.h>
30#include <linux/statfs.h>
31#include <linux/compat.h>
Chris Mason92fee662007-07-25 12:31:35 -040032#include <linux/version.h>
Chris Mason39279cc2007-06-12 06:35:45 -040033#include "ctree.h"
34#include "disk-io.h"
35#include "transaction.h"
36#include "btrfs_inode.h"
37#include "ioctl.h"
38#include "print-tree.h"
39
40
41static int btrfs_copy_from_user(loff_t pos, int num_pages, int write_bytes,
42 struct page **prepared_pages,
43 const char __user * buf)
44{
45 long page_fault = 0;
46 int i;
47 int offset = pos & (PAGE_CACHE_SIZE - 1);
48
49 for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
50 size_t count = min_t(size_t,
51 PAGE_CACHE_SIZE - offset, write_bytes);
52 struct page *page = prepared_pages[i];
53 fault_in_pages_readable(buf, count);
54
55 /* Copy data from userspace to the current page */
56 kmap(page);
57 page_fault = __copy_from_user(page_address(page) + offset,
58 buf, count);
59 /* Flush processor's dcache for this page */
60 flush_dcache_page(page);
61 kunmap(page);
62 buf += count;
63 write_bytes -= count;
64
65 if (page_fault)
66 break;
67 }
68 return page_fault ? -EFAULT : 0;
69}
70
71static void btrfs_drop_pages(struct page **pages, size_t num_pages)
72{
73 size_t i;
74 for (i = 0; i < num_pages; i++) {
75 if (!pages[i])
76 break;
77 unlock_page(pages[i]);
78 mark_page_accessed(pages[i]);
79 page_cache_release(pages[i]);
80 }
81}
82
Chris Masona52d9a82007-08-27 16:49:44 -040083static int insert_inline_extent(struct btrfs_trans_handle *trans,
84 struct btrfs_root *root, struct inode *inode,
Chris Mason3326d1b2007-10-15 16:18:25 -040085 u64 offset, size_t size,
86 struct page **pages, size_t page_offset,
87 int num_pages)
Chris Mason54aa1f42007-06-22 14:16:25 -040088{
89 struct btrfs_key key;
90 struct btrfs_path *path;
Chris Mason5f39d392007-10-15 16:14:19 -040091 struct extent_buffer *leaf;
92 char *kaddr;
93 unsigned long ptr;
Chris Mason54aa1f42007-06-22 14:16:25 -040094 struct btrfs_file_extent_item *ei;
Chris Mason3326d1b2007-10-15 16:18:25 -040095 struct page *page;
Chris Mason54aa1f42007-06-22 14:16:25 -040096 u32 datasize;
97 int err = 0;
98 int ret;
Chris Mason3326d1b2007-10-15 16:18:25 -040099 int i;
100 ssize_t cur_size;
Chris Mason54aa1f42007-06-22 14:16:25 -0400101
102 path = btrfs_alloc_path();
103 if (!path)
104 return -ENOMEM;
105
Chris Mason54aa1f42007-06-22 14:16:25 -0400106 btrfs_set_trans_block_group(trans, inode);
107
108 key.objectid = inode->i_ino;
109 key.offset = offset;
Chris Mason54aa1f42007-06-22 14:16:25 -0400110 btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
Chris Mason54aa1f42007-06-22 14:16:25 -0400111
Chris Mason3326d1b2007-10-15 16:18:25 -0400112 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
113 if (ret < 0) {
Chris Mason54aa1f42007-06-22 14:16:25 -0400114 err = ret;
115 goto fail;
116 }
Chris Mason3326d1b2007-10-15 16:18:25 -0400117 if (ret == 1) {
Chris Mason179e29e2007-11-01 11:28:41 -0400118 struct btrfs_key found_key;
119
120 if (path->slots[0] == 0)
121 goto insert;
122
Chris Mason3326d1b2007-10-15 16:18:25 -0400123 path->slots[0]--;
124 leaf = path->nodes[0];
Chris Mason179e29e2007-11-01 11:28:41 -0400125 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
126
127 if (found_key.objectid != inode->i_ino)
128 goto insert;
129
130 if (found_key.type != BTRFS_EXTENT_DATA_KEY)
131 goto insert;
Chris Mason3326d1b2007-10-15 16:18:25 -0400132 ei = btrfs_item_ptr(leaf, path->slots[0],
133 struct btrfs_file_extent_item);
Chris Mason54aa1f42007-06-22 14:16:25 -0400134
Chris Mason3326d1b2007-10-15 16:18:25 -0400135 if (btrfs_file_extent_type(leaf, ei) !=
136 BTRFS_FILE_EXTENT_INLINE) {
137 goto insert;
138 }
139 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
140 ret = 0;
141 }
142 if (ret == 0) {
143 u32 found_size;
Yan18f16f72007-10-25 15:42:57 -0400144 u64 found_end;
Chris Mason3326d1b2007-10-15 16:18:25 -0400145
146 leaf = path->nodes[0];
147 ei = btrfs_item_ptr(leaf, path->slots[0],
148 struct btrfs_file_extent_item);
149
150 if (btrfs_file_extent_type(leaf, ei) !=
151 BTRFS_FILE_EXTENT_INLINE) {
152 err = ret;
153 btrfs_print_leaf(root, leaf);
154 printk("found wasn't inline offset %Lu inode %lu\n",
155 offset, inode->i_ino);
156 goto fail;
157 }
Chris Mason3326d1b2007-10-15 16:18:25 -0400158 found_size = btrfs_file_extent_inline_len(leaf,
159 btrfs_item_nr(leaf, path->slots[0]));
Yan18f16f72007-10-25 15:42:57 -0400160 found_end = key.offset + found_size;
Chris Mason3326d1b2007-10-15 16:18:25 -0400161
Yan18f16f72007-10-25 15:42:57 -0400162 if (found_end < offset + size) {
Chris Mason3326d1b2007-10-15 16:18:25 -0400163 btrfs_release_path(root, path);
164 ret = btrfs_search_slot(trans, root, &key, path,
Yan18f16f72007-10-25 15:42:57 -0400165 offset + size - found_end, 1);
Chris Mason3326d1b2007-10-15 16:18:25 -0400166 BUG_ON(ret != 0);
Chris Mason179e29e2007-11-01 11:28:41 -0400167
Chris Mason3326d1b2007-10-15 16:18:25 -0400168 ret = btrfs_extend_item(trans, root, path,
Yan18f16f72007-10-25 15:42:57 -0400169 offset + size - found_end);
Chris Mason3326d1b2007-10-15 16:18:25 -0400170 if (ret) {
171 err = ret;
172 goto fail;
173 }
174 leaf = path->nodes[0];
175 ei = btrfs_item_ptr(leaf, path->slots[0],
176 struct btrfs_file_extent_item);
177 }
Yan18f16f72007-10-25 15:42:57 -0400178 if (found_end < offset) {
179 ptr = btrfs_file_extent_inline_start(ei) + found_size;
180 memset_extent_buffer(leaf, 0, ptr, offset - found_end);
181 }
Chris Mason3326d1b2007-10-15 16:18:25 -0400182 } else {
183insert:
184 btrfs_release_path(root, path);
Yan18f16f72007-10-25 15:42:57 -0400185 datasize = offset + size - key.offset;
186 datasize = btrfs_file_extent_calc_inline_size(datasize);
Chris Mason3326d1b2007-10-15 16:18:25 -0400187 ret = btrfs_insert_empty_item(trans, root, path, &key,
188 datasize);
189 if (ret) {
190 err = ret;
191 printk("got bad ret %d\n", ret);
192 goto fail;
193 }
194 leaf = path->nodes[0];
195 ei = btrfs_item_ptr(leaf, path->slots[0],
196 struct btrfs_file_extent_item);
197 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
198 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
199 }
Yan18f16f72007-10-25 15:42:57 -0400200 ptr = btrfs_file_extent_inline_start(ei) + offset - key.offset;
Chris Mason3326d1b2007-10-15 16:18:25 -0400201
202 cur_size = size;
203 i = 0;
204 while (size > 0) {
205 page = pages[i];
206 kaddr = kmap_atomic(page, KM_USER0);
Jens Axboeae2f5412007-10-19 09:22:59 -0400207 cur_size = min_t(size_t, PAGE_CACHE_SIZE - page_offset, size);
Chris Mason3326d1b2007-10-15 16:18:25 -0400208 write_extent_buffer(leaf, kaddr + page_offset, ptr, cur_size);
209 kunmap_atomic(kaddr, KM_USER0);
210 page_offset = 0;
211 ptr += cur_size;
212 size -= cur_size;
213 if (i >= num_pages) {
214 printk("i %d num_pages %d\n", i, num_pages);
215 }
216 i++;
217 }
Chris Mason5f39d392007-10-15 16:14:19 -0400218 btrfs_mark_buffer_dirty(leaf);
Chris Mason54aa1f42007-06-22 14:16:25 -0400219fail:
220 btrfs_free_path(path);
Chris Mason54aa1f42007-06-22 14:16:25 -0400221 return err;
222}
223
Chris Mason39279cc2007-06-12 06:35:45 -0400224static int dirty_and_release_pages(struct btrfs_trans_handle *trans,
225 struct btrfs_root *root,
226 struct file *file,
227 struct page **pages,
228 size_t num_pages,
229 loff_t pos,
230 size_t write_bytes)
231{
Chris Mason39279cc2007-06-12 06:35:45 -0400232 int err = 0;
Chris Masona52d9a82007-08-27 16:49:44 -0400233 int i;
Chris Mason39279cc2007-06-12 06:35:45 -0400234 struct inode *inode = file->f_path.dentry->d_inode;
Chris Masona52d9a82007-08-27 16:49:44 -0400235 struct extent_map *em;
236 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
Chris Masondb945352007-10-15 16:15:53 -0400237 u64 hint_byte;
238 u64 num_bytes;
Chris Masona52d9a82007-08-27 16:49:44 -0400239 u64 start_pos;
240 u64 end_of_last_block;
241 u64 end_pos = pos + write_bytes;
Yandcfec0d2007-11-06 10:26:26 -0500242 u64 inline_size;
Chris Masona52d9a82007-08-27 16:49:44 -0400243 loff_t isize = i_size_read(inode);
Chris Masona52d9a82007-08-27 16:49:44 -0400244 em = alloc_extent_map(GFP_NOFS);
245 if (!em)
246 return -ENOMEM;
Chris Mason39279cc2007-06-12 06:35:45 -0400247
Chris Masona52d9a82007-08-27 16:49:44 -0400248 em->bdev = inode->i_sb->s_bdev;
Chris Mason39279cc2007-06-12 06:35:45 -0400249
Chris Mason5f39d392007-10-15 16:14:19 -0400250 start_pos = pos & ~((u64)root->sectorsize - 1);
Chris Masondb945352007-10-15 16:15:53 -0400251 num_bytes = (write_bytes + pos - start_pos +
252 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
Chris Mason39279cc2007-06-12 06:35:45 -0400253
Chris Mason011410b2007-09-10 19:58:36 -0400254 down_read(&BTRFS_I(inode)->root->snap_sem);
Chris Masondb945352007-10-15 16:15:53 -0400255 end_of_last_block = start_pos + num_bytes - 1;
256
Chris Masonb888db22007-08-27 16:49:44 -0400257 lock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
Chris Masona52d9a82007-08-27 16:49:44 -0400258 mutex_lock(&root->fs_info->fs_mutex);
259 trans = btrfs_start_transaction(root, 1);
260 if (!trans) {
261 err = -ENOMEM;
262 goto out_unlock;
263 }
264 btrfs_set_trans_block_group(trans, inode);
Chris Masondb945352007-10-15 16:15:53 -0400265 inode->i_blocks += num_bytes >> 9;
266 hint_byte = 0;
Chris Masona52d9a82007-08-27 16:49:44 -0400267
268 if ((end_of_last_block & 4095) == 0) {
Christoph Hellwig94330632007-09-10 20:02:22 -0400269 printk("strange end of last %Lu %zu %Lu\n", start_pos, write_bytes, end_of_last_block);
Chris Masona52d9a82007-08-27 16:49:44 -0400270 }
271 set_extent_uptodate(em_tree, start_pos, end_of_last_block, GFP_NOFS);
272
273 /* FIXME...EIEIO, ENOSPC and more */
274
Chris Masona52d9a82007-08-27 16:49:44 -0400275 /* insert any holes we need to create */
276 if (inode->i_size < start_pos) {
277 u64 last_pos_in_file;
278 u64 hole_size;
Chris Mason5f39d392007-10-15 16:14:19 -0400279 u64 mask = root->sectorsize - 1;
Chris Masona52d9a82007-08-27 16:49:44 -0400280 last_pos_in_file = (isize + mask) & ~mask;
281 hole_size = (start_pos - last_pos_in_file + mask) & ~mask;
Chris Mason2bf5a722007-08-30 11:54:02 -0400282
Chris Masona52d9a82007-08-27 16:49:44 -0400283 if (last_pos_in_file < start_pos) {
Chris Mason2bf5a722007-08-30 11:54:02 -0400284 err = btrfs_drop_extents(trans, root, inode,
285 last_pos_in_file,
286 last_pos_in_file + hole_size,
Chris Mason3326d1b2007-10-15 16:18:25 -0400287 last_pos_in_file,
Chris Masondb945352007-10-15 16:15:53 -0400288 &hint_byte);
Chris Mason2bf5a722007-08-30 11:54:02 -0400289 if (err)
290 goto failed;
291
Chris Masona52d9a82007-08-27 16:49:44 -0400292 err = btrfs_insert_file_extent(trans, root,
293 inode->i_ino,
294 last_pos_in_file,
295 0, 0, hole_size);
Chris Mason39279cc2007-06-12 06:35:45 -0400296 }
Chris Masona52d9a82007-08-27 16:49:44 -0400297 if (err)
298 goto failed;
299 }
300
301 /*
302 * either allocate an extent for the new bytes or setup the key
303 * to show we are doing inline data in the extent
304 */
Chris Mason3326d1b2007-10-15 16:18:25 -0400305 inline_size = end_pos;
306 if (isize >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
Chris Mason179e29e2007-11-01 11:28:41 -0400307 inline_size > 32768 ||
Chris Mason3326d1b2007-10-15 16:18:25 -0400308 inline_size >= BTRFS_MAX_INLINE_DATA_SIZE(root)) {
Chris Masonb888db22007-08-27 16:49:44 -0400309 u64 last_end;
Chris Mason3326d1b2007-10-15 16:18:25 -0400310
Chris Masona52d9a82007-08-27 16:49:44 -0400311 for (i = 0; i < num_pages; i++) {
312 struct page *p = pages[i];
313 SetPageUptodate(p);
Chris Masonb888db22007-08-27 16:49:44 -0400314 set_page_dirty(p);
Chris Masona52d9a82007-08-27 16:49:44 -0400315 }
Chris Mason35ebb932007-10-30 16:56:53 -0400316 last_end = (u64)(pages[num_pages -1]->index) <<
317 PAGE_CACHE_SHIFT;
Chris Masonb888db22007-08-27 16:49:44 -0400318 last_end += PAGE_CACHE_SIZE - 1;
319 set_extent_delalloc(em_tree, start_pos, end_of_last_block,
320 GFP_NOFS);
Chris Masona52d9a82007-08-27 16:49:44 -0400321 } else {
Chris Mason3326d1b2007-10-15 16:18:25 -0400322 u64 aligned_end;
Chris Masonb888db22007-08-27 16:49:44 -0400323 /* step one, delete the existing extents in this range */
Chris Mason3326d1b2007-10-15 16:18:25 -0400324 aligned_end = (pos + write_bytes + root->sectorsize - 1) &
325 ~((u64)root->sectorsize - 1);
Chris Mason2bf5a722007-08-30 11:54:02 -0400326 err = btrfs_drop_extents(trans, root, inode, start_pos,
Chris Mason179e29e2007-11-01 11:28:41 -0400327 aligned_end, aligned_end, &hint_byte);
Chris Mason2bf5a722007-08-30 11:54:02 -0400328 if (err)
329 goto failed;
Yandcfec0d2007-11-06 10:26:26 -0500330 if (isize > inline_size)
331 inline_size = min_t(u64, isize, aligned_end);
332 inline_size -= start_pos;
Chris Masona52d9a82007-08-27 16:49:44 -0400333 err = insert_inline_extent(trans, root, inode, start_pos,
Yandcfec0d2007-11-06 10:26:26 -0500334 inline_size, pages, 0, num_pages);
Chris Masona52d9a82007-08-27 16:49:44 -0400335 BUG_ON(err);
Chris Masona52d9a82007-08-27 16:49:44 -0400336 }
337 if (end_pos > isize) {
338 i_size_write(inode, end_pos);
339 btrfs_update_inode(trans, root, inode);
Chris Mason39279cc2007-06-12 06:35:45 -0400340 }
341failed:
Chris Masona52d9a82007-08-27 16:49:44 -0400342 err = btrfs_end_transaction(trans, root);
343out_unlock:
344 mutex_unlock(&root->fs_info->fs_mutex);
Chris Masonb888db22007-08-27 16:49:44 -0400345 unlock_extent(em_tree, start_pos, end_of_last_block, GFP_NOFS);
Chris Masona52d9a82007-08-27 16:49:44 -0400346 free_extent_map(em);
Chris Mason011410b2007-09-10 19:58:36 -0400347 up_read(&BTRFS_I(inode)->root->snap_sem);
Chris Mason39279cc2007-06-12 06:35:45 -0400348 return err;
349}
350
Chris Masona52d9a82007-08-27 16:49:44 -0400351int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end)
352{
353 struct extent_map *em;
354 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
355
356 while(1) {
357 em = lookup_extent_mapping(em_tree, start, end);
358 if (!em)
359 break;
360 remove_extent_mapping(em_tree, em);
361 /* once for us */
362 free_extent_map(em);
363 /* once for the tree*/
364 free_extent_map(em);
365 }
366 return 0;
367}
368
Chris Mason39279cc2007-06-12 06:35:45 -0400369/*
370 * this is very complex, but the basic idea is to drop all extents
371 * in the range start - end. hint_block is filled in with a block number
372 * that would be a good hint to the block allocator for this file.
373 *
374 * If an extent intersects the range but is not entirely inside the range
375 * it is either truncated or split. Anything entirely inside the range
376 * is deleted from the tree.
377 */
378int btrfs_drop_extents(struct btrfs_trans_handle *trans,
379 struct btrfs_root *root, struct inode *inode,
Chris Mason3326d1b2007-10-15 16:18:25 -0400380 u64 start, u64 end, u64 inline_end, u64 *hint_byte)
Chris Mason39279cc2007-06-12 06:35:45 -0400381{
382 int ret;
383 struct btrfs_key key;
Chris Mason5f39d392007-10-15 16:14:19 -0400384 struct extent_buffer *leaf;
Chris Mason39279cc2007-06-12 06:35:45 -0400385 int slot;
386 struct btrfs_file_extent_item *extent;
387 u64 extent_end = 0;
388 int keep;
389 struct btrfs_file_extent_item old;
390 struct btrfs_path *path;
391 u64 search_start = start;
392 int bookend;
393 int found_type;
394 int found_extent;
395 int found_inline;
Chris Masonccd467d2007-06-28 15:57:36 -0400396 int recow;
Chris Mason39279cc2007-06-12 06:35:45 -0400397
Chris Masona52d9a82007-08-27 16:49:44 -0400398 btrfs_drop_extent_cache(inode, start, end - 1);
399
Chris Mason39279cc2007-06-12 06:35:45 -0400400 path = btrfs_alloc_path();
401 if (!path)
402 return -ENOMEM;
403 while(1) {
Chris Masonccd467d2007-06-28 15:57:36 -0400404 recow = 0;
Chris Mason39279cc2007-06-12 06:35:45 -0400405 btrfs_release_path(root, path);
406 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
407 search_start, -1);
408 if (ret < 0)
409 goto out;
410 if (ret > 0) {
411 if (path->slots[0] == 0) {
412 ret = 0;
413 goto out;
414 }
415 path->slots[0]--;
416 }
Chris Mason8c2383c2007-06-18 09:57:58 -0400417next_slot:
Chris Mason39279cc2007-06-12 06:35:45 -0400418 keep = 0;
419 bookend = 0;
420 found_extent = 0;
421 found_inline = 0;
422 extent = NULL;
Chris Mason5f39d392007-10-15 16:14:19 -0400423 leaf = path->nodes[0];
Chris Mason39279cc2007-06-12 06:35:45 -0400424 slot = path->slots[0];
Chris Mason8c2383c2007-06-18 09:57:58 -0400425 ret = 0;
Chris Mason5f39d392007-10-15 16:14:19 -0400426 btrfs_item_key_to_cpu(leaf, &key, slot);
Chris Mason39279cc2007-06-12 06:35:45 -0400427 if (key.offset >= end || key.objectid != inode->i_ino) {
Chris Mason39279cc2007-06-12 06:35:45 -0400428 goto out;
429 }
Chris Mason8c2383c2007-06-18 09:57:58 -0400430 if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY) {
Chris Mason39279cc2007-06-12 06:35:45 -0400431 goto out;
432 }
Chris Masonccd467d2007-06-28 15:57:36 -0400433 if (recow) {
434 search_start = key.offset;
435 continue;
436 }
Chris Mason8c2383c2007-06-18 09:57:58 -0400437 if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
438 extent = btrfs_item_ptr(leaf, slot,
439 struct btrfs_file_extent_item);
Chris Mason5f39d392007-10-15 16:14:19 -0400440 found_type = btrfs_file_extent_type(leaf, extent);
Chris Mason8c2383c2007-06-18 09:57:58 -0400441 if (found_type == BTRFS_FILE_EXTENT_REG) {
442 extent_end = key.offset +
Chris Masondb945352007-10-15 16:15:53 -0400443 btrfs_file_extent_num_bytes(leaf, extent);
Chris Mason8c2383c2007-06-18 09:57:58 -0400444 found_extent = 1;
445 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
Chris Mason5f39d392007-10-15 16:14:19 -0400446 struct btrfs_item *item;
447 item = btrfs_item_nr(leaf, slot);
Chris Mason8c2383c2007-06-18 09:57:58 -0400448 found_inline = 1;
449 extent_end = key.offset +
Chris Mason5f39d392007-10-15 16:14:19 -0400450 btrfs_file_extent_inline_len(leaf, item);
Chris Mason8c2383c2007-06-18 09:57:58 -0400451 }
452 } else {
453 extent_end = search_start;
Chris Mason39279cc2007-06-12 06:35:45 -0400454 }
455
456 /* we found nothing we can drop */
Chris Mason8c2383c2007-06-18 09:57:58 -0400457 if ((!found_extent && !found_inline) ||
458 search_start >= extent_end) {
459 int nextret;
460 u32 nritems;
Chris Mason5f39d392007-10-15 16:14:19 -0400461 nritems = btrfs_header_nritems(leaf);
Chris Mason8c2383c2007-06-18 09:57:58 -0400462 if (slot >= nritems - 1) {
463 nextret = btrfs_next_leaf(root, path);
464 if (nextret)
465 goto out;
Chris Masonccd467d2007-06-28 15:57:36 -0400466 recow = 1;
Chris Mason8c2383c2007-06-18 09:57:58 -0400467 } else {
468 path->slots[0]++;
469 }
470 goto next_slot;
Chris Mason39279cc2007-06-12 06:35:45 -0400471 }
472
Chris Mason39279cc2007-06-12 06:35:45 -0400473 if (found_inline) {
Chris Mason5f39d392007-10-15 16:14:19 -0400474 u64 mask = root->sectorsize - 1;
Chris Mason39279cc2007-06-12 06:35:45 -0400475 search_start = (extent_end + mask) & ~mask;
476 } else
477 search_start = extent_end;
478
Chris Mason179e29e2007-11-01 11:28:41 -0400479 if (end <= extent_end && start >= key.offset && found_inline) {
480 *hint_byte = EXTENT_MAP_INLINE;
481 }
Chris Mason39279cc2007-06-12 06:35:45 -0400482 if (end < extent_end && end >= key.offset) {
483 if (found_extent) {
Chris Masondb945352007-10-15 16:15:53 -0400484 u64 disk_bytenr =
485 btrfs_file_extent_disk_bytenr(leaf, extent);
486 u64 disk_num_bytes =
487 btrfs_file_extent_disk_num_bytes(leaf,
Chris Mason5f39d392007-10-15 16:14:19 -0400488 extent);
489 read_extent_buffer(leaf, &old,
490 (unsigned long)extent,
491 sizeof(old));
Chris Masondb945352007-10-15 16:15:53 -0400492 if (disk_bytenr != 0) {
Chris Mason39279cc2007-06-12 06:35:45 -0400493 ret = btrfs_inc_extent_ref(trans, root,
Chris Masondb945352007-10-15 16:15:53 -0400494 disk_bytenr, disk_num_bytes);
Chris Mason39279cc2007-06-12 06:35:45 -0400495 BUG_ON(ret);
496 }
497 }
Chris Mason179e29e2007-11-01 11:28:41 -0400498 bookend = 1;
499 if (found_inline && start <= key.offset &&
500 inline_end < extent_end)
501 keep = 1;
Chris Mason39279cc2007-06-12 06:35:45 -0400502 }
Chris Mason39279cc2007-06-12 06:35:45 -0400503 /* truncate existing extent */
504 if (start > key.offset) {
505 u64 new_num;
506 u64 old_num;
507 keep = 1;
Chris Mason5f39d392007-10-15 16:14:19 -0400508 WARN_ON(start & (root->sectorsize - 1));
Chris Mason39279cc2007-06-12 06:35:45 -0400509 if (found_extent) {
Chris Masondb945352007-10-15 16:15:53 -0400510 new_num = start - key.offset;
511 old_num = btrfs_file_extent_num_bytes(leaf,
512 extent);
513 *hint_byte =
514 btrfs_file_extent_disk_bytenr(leaf,
515 extent);
516 if (btrfs_file_extent_disk_bytenr(leaf,
517 extent)) {
Chris Mason39279cc2007-06-12 06:35:45 -0400518 inode->i_blocks -=
Chris Masondb945352007-10-15 16:15:53 -0400519 (old_num - new_num) >> 9;
Chris Mason39279cc2007-06-12 06:35:45 -0400520 }
Chris Masondb945352007-10-15 16:15:53 -0400521 btrfs_set_file_extent_num_bytes(leaf, extent,
522 new_num);
Chris Mason5f39d392007-10-15 16:14:19 -0400523 btrfs_mark_buffer_dirty(leaf);
Chris Mason3326d1b2007-10-15 16:18:25 -0400524 } else if (end > extent_end &&
525 key.offset < inline_end &&
526 inline_end < extent_end) {
527 u32 new_size;
528 new_size = btrfs_file_extent_calc_inline_size(
529 inline_end - key.offset);
530 btrfs_truncate_item(trans, root, path,
Chris Mason179e29e2007-11-01 11:28:41 -0400531 new_size, 1);
Chris Mason39279cc2007-06-12 06:35:45 -0400532 }
533 }
534 /* delete the entire extent */
535 if (!keep) {
Chris Masondb945352007-10-15 16:15:53 -0400536 u64 disk_bytenr = 0;
537 u64 disk_num_bytes = 0;
538 u64 extent_num_bytes = 0;
Chris Mason39279cc2007-06-12 06:35:45 -0400539 if (found_extent) {
Chris Masondb945352007-10-15 16:15:53 -0400540 disk_bytenr =
541 btrfs_file_extent_disk_bytenr(leaf,
Chris Mason5f39d392007-10-15 16:14:19 -0400542 extent);
Chris Masondb945352007-10-15 16:15:53 -0400543 disk_num_bytes =
544 btrfs_file_extent_disk_num_bytes(leaf,
Chris Mason5f39d392007-10-15 16:14:19 -0400545 extent);
Chris Masondb945352007-10-15 16:15:53 -0400546 extent_num_bytes =
547 btrfs_file_extent_num_bytes(leaf, extent);
548 *hint_byte =
549 btrfs_file_extent_disk_bytenr(leaf,
550 extent);
Chris Mason39279cc2007-06-12 06:35:45 -0400551 }
552 ret = btrfs_del_item(trans, root, path);
Chris Mason54aa1f42007-06-22 14:16:25 -0400553 /* TODO update progress marker and return */
Chris Mason39279cc2007-06-12 06:35:45 -0400554 BUG_ON(ret);
555 btrfs_release_path(root, path);
556 extent = NULL;
Chris Masondb945352007-10-15 16:15:53 -0400557 if (found_extent && disk_bytenr != 0) {
558 inode->i_blocks -= extent_num_bytes >> 9;
Chris Mason39279cc2007-06-12 06:35:45 -0400559 ret = btrfs_free_extent(trans, root,
Chris Masondb945352007-10-15 16:15:53 -0400560 disk_bytenr,
561 disk_num_bytes, 0);
Chris Mason39279cc2007-06-12 06:35:45 -0400562 }
563
564 BUG_ON(ret);
565 if (!bookend && search_start >= end) {
566 ret = 0;
567 goto out;
568 }
569 if (!bookend)
570 continue;
571 }
Chris Mason179e29e2007-11-01 11:28:41 -0400572 if (bookend && found_inline && start <= key.offset &&
573 inline_end < extent_end) {
574 u32 new_size;
575 new_size = btrfs_file_extent_calc_inline_size(
576 extent_end - inline_end);
577 btrfs_truncate_item(trans, root, path, new_size, 0);
578 }
Chris Mason39279cc2007-06-12 06:35:45 -0400579 /* create bookend, splitting the extent in two */
580 if (bookend && found_extent) {
581 struct btrfs_key ins;
582 ins.objectid = inode->i_ino;
583 ins.offset = end;
Chris Mason39279cc2007-06-12 06:35:45 -0400584 btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
Chris Mason39279cc2007-06-12 06:35:45 -0400585 btrfs_release_path(root, path);
586 ret = btrfs_insert_empty_item(trans, root, path, &ins,
587 sizeof(*extent));
Chris Mason8c2383c2007-06-18 09:57:58 -0400588
Chris Mason5f39d392007-10-15 16:14:19 -0400589 leaf = path->nodes[0];
Chris Mason8c2383c2007-06-18 09:57:58 -0400590 if (ret) {
Chris Mason5f39d392007-10-15 16:14:19 -0400591 btrfs_print_leaf(root, leaf);
592 printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret , ins.objectid, ins.type, ins.offset, start, end, key.offset, extent_end, keep);
Chris Mason8c2383c2007-06-18 09:57:58 -0400593 }
Chris Mason39279cc2007-06-12 06:35:45 -0400594 BUG_ON(ret);
Chris Mason5f39d392007-10-15 16:14:19 -0400595 extent = btrfs_item_ptr(leaf, path->slots[0],
596 struct btrfs_file_extent_item);
597 write_extent_buffer(leaf, &old,
598 (unsigned long)extent, sizeof(old));
Chris Mason39279cc2007-06-12 06:35:45 -0400599
Chris Mason5f39d392007-10-15 16:14:19 -0400600 btrfs_set_file_extent_offset(leaf, extent,
Chris Masondb945352007-10-15 16:15:53 -0400601 le64_to_cpu(old.offset) + end - key.offset);
602 WARN_ON(le64_to_cpu(old.num_bytes) <
603 (extent_end - end));
604 btrfs_set_file_extent_num_bytes(leaf, extent,
605 extent_end - end);
Chris Mason5f39d392007-10-15 16:14:19 -0400606 btrfs_set_file_extent_type(leaf, extent,
Chris Mason39279cc2007-06-12 06:35:45 -0400607 BTRFS_FILE_EXTENT_REG);
Chris Masondb945352007-10-15 16:15:53 -0400608
Chris Mason39279cc2007-06-12 06:35:45 -0400609 btrfs_mark_buffer_dirty(path->nodes[0]);
Chris Masondb945352007-10-15 16:15:53 -0400610 if (le64_to_cpu(old.disk_bytenr) != 0) {
Chris Mason39279cc2007-06-12 06:35:45 -0400611 inode->i_blocks +=
Chris Masondb945352007-10-15 16:15:53 -0400612 btrfs_file_extent_num_bytes(leaf,
613 extent) >> 9;
Chris Mason39279cc2007-06-12 06:35:45 -0400614 }
615 ret = 0;
616 goto out;
617 }
618 }
619out:
620 btrfs_free_path(path);
621 return ret;
622}
623
624/*
625 * this gets pages into the page cache and locks them down
626 */
627static int prepare_pages(struct btrfs_root *root,
628 struct file *file,
629 struct page **pages,
630 size_t num_pages,
631 loff_t pos,
632 unsigned long first_index,
633 unsigned long last_index,
Chris Mason8c2383c2007-06-18 09:57:58 -0400634 size_t write_bytes)
Chris Mason39279cc2007-06-12 06:35:45 -0400635{
636 int i;
637 unsigned long index = pos >> PAGE_CACHE_SHIFT;
638 struct inode *inode = file->f_path.dentry->d_inode;
Chris Mason39279cc2007-06-12 06:35:45 -0400639 int err = 0;
Chris Mason8c2383c2007-06-18 09:57:58 -0400640 u64 start_pos;
Chris Mason8c2383c2007-06-18 09:57:58 -0400641
Chris Mason5f39d392007-10-15 16:14:19 -0400642 start_pos = pos & ~((u64)root->sectorsize - 1);
Chris Mason39279cc2007-06-12 06:35:45 -0400643
644 memset(pages, 0, num_pages * sizeof(struct page *));
645
646 for (i = 0; i < num_pages; i++) {
647 pages[i] = grab_cache_page(inode->i_mapping, index + i);
648 if (!pages[i]) {
649 err = -ENOMEM;
Chris Masona52d9a82007-08-27 16:49:44 -0400650 BUG_ON(1);
Chris Mason39279cc2007-06-12 06:35:45 -0400651 }
Chris Masonccd467d2007-06-28 15:57:36 -0400652 cancel_dirty_page(pages[i], PAGE_CACHE_SIZE);
653 wait_on_page_writeback(pages[i]);
Christoph Hellwigb3cfa352007-09-17 11:25:58 -0400654 set_page_extent_mapped(pages[i]);
Chris Masonb888db22007-08-27 16:49:44 -0400655 WARN_ON(!PageLocked(pages[i]));
Chris Mason39279cc2007-06-12 06:35:45 -0400656 }
657 return 0;
Chris Mason39279cc2007-06-12 06:35:45 -0400658}
659
660static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
661 size_t count, loff_t *ppos)
662{
663 loff_t pos;
Chris Mason2ff3e9b2007-10-29 14:36:41 -0400664 loff_t start_pos;
665 ssize_t num_written = 0;
666 ssize_t err = 0;
Chris Mason39279cc2007-06-12 06:35:45 -0400667 int ret = 0;
668 struct inode *inode = file->f_path.dentry->d_inode;
669 struct btrfs_root *root = BTRFS_I(inode)->root;
Chris Mason8c2383c2007-06-18 09:57:58 -0400670 struct page **pages = NULL;
671 int nrptrs;
Chris Mason39279cc2007-06-12 06:35:45 -0400672 struct page *pinned[2];
673 unsigned long first_index;
674 unsigned long last_index;
Chris Mason8c2383c2007-06-18 09:57:58 -0400675
676 nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
677 PAGE_CACHE_SIZE / (sizeof(struct page *)));
Chris Mason39279cc2007-06-12 06:35:45 -0400678 pinned[0] = NULL;
679 pinned[1] = NULL;
680 if (file->f_flags & O_DIRECT)
681 return -EINVAL;
Chris Mason2ff3e9b2007-10-29 14:36:41 -0400682
Chris Mason39279cc2007-06-12 06:35:45 -0400683 pos = *ppos;
Chris Mason2ff3e9b2007-10-29 14:36:41 -0400684 start_pos = pos;
685
Chris Mason39279cc2007-06-12 06:35:45 -0400686 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
687 current->backing_dev_info = inode->i_mapping->backing_dev_info;
688 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
689 if (err)
690 goto out;
691 if (count == 0)
692 goto out;
693 err = remove_suid(file->f_path.dentry);
694 if (err)
695 goto out;
696 file_update_time(file);
697
Chris Mason8c2383c2007-06-18 09:57:58 -0400698 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
Chris Mason39279cc2007-06-12 06:35:45 -0400699
700 mutex_lock(&inode->i_mutex);
701 first_index = pos >> PAGE_CACHE_SHIFT;
702 last_index = (pos + count) >> PAGE_CACHE_SHIFT;
703
704 /*
705 * there are lots of better ways to do this, but this code
706 * makes sure the first and last page in the file range are
707 * up to date and ready for cow
708 */
709 if ((pos & (PAGE_CACHE_SIZE - 1))) {
710 pinned[0] = grab_cache_page(inode->i_mapping, first_index);
711 if (!PageUptodate(pinned[0])) {
Chris Mason9ebefb182007-06-15 13:50:00 -0400712 ret = btrfs_readpage(NULL, pinned[0]);
Chris Mason39279cc2007-06-12 06:35:45 -0400713 BUG_ON(ret);
714 wait_on_page_locked(pinned[0]);
715 } else {
716 unlock_page(pinned[0]);
717 }
718 }
719 if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
720 pinned[1] = grab_cache_page(inode->i_mapping, last_index);
721 if (!PageUptodate(pinned[1])) {
Chris Mason9ebefb182007-06-15 13:50:00 -0400722 ret = btrfs_readpage(NULL, pinned[1]);
Chris Mason39279cc2007-06-12 06:35:45 -0400723 BUG_ON(ret);
724 wait_on_page_locked(pinned[1]);
725 } else {
726 unlock_page(pinned[1]);
727 }
728 }
729
Chris Mason39279cc2007-06-12 06:35:45 -0400730 while(count > 0) {
731 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
Chris Mason11bd1432007-06-22 14:16:24 -0400732 size_t write_bytes = min(count, nrptrs *
733 (size_t)PAGE_CACHE_SIZE -
Chris Mason8c2383c2007-06-18 09:57:58 -0400734 offset);
Chris Mason39279cc2007-06-12 06:35:45 -0400735 size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
736 PAGE_CACHE_SHIFT;
737
Chris Mason8c2383c2007-06-18 09:57:58 -0400738 WARN_ON(num_pages > nrptrs);
Chris Mason39279cc2007-06-12 06:35:45 -0400739 memset(pages, 0, sizeof(pages));
740 ret = prepare_pages(root, file, pages, num_pages,
741 pos, first_index, last_index,
Chris Mason8c2383c2007-06-18 09:57:58 -0400742 write_bytes);
Chris Mason54aa1f42007-06-22 14:16:25 -0400743 if (ret)
744 goto out;
Chris Mason39279cc2007-06-12 06:35:45 -0400745
Chris Mason39279cc2007-06-12 06:35:45 -0400746 ret = btrfs_copy_from_user(pos, num_pages,
747 write_bytes, pages, buf);
Chris Mason54aa1f42007-06-22 14:16:25 -0400748 if (ret) {
749 btrfs_drop_pages(pages, num_pages);
750 goto out;
751 }
Chris Mason39279cc2007-06-12 06:35:45 -0400752
753 ret = dirty_and_release_pages(NULL, root, file, pages,
754 num_pages, pos, write_bytes);
Chris Mason39279cc2007-06-12 06:35:45 -0400755 btrfs_drop_pages(pages, num_pages);
Chris Mason54aa1f42007-06-22 14:16:25 -0400756 if (ret)
757 goto out;
Chris Mason39279cc2007-06-12 06:35:45 -0400758
759 buf += write_bytes;
760 count -= write_bytes;
761 pos += write_bytes;
762 num_written += write_bytes;
763
Chris Mason8c2383c2007-06-18 09:57:58 -0400764 balance_dirty_pages_ratelimited_nr(inode->i_mapping, num_pages);
Chris Masond3c2fdcf2007-09-17 10:58:06 -0400765 btrfs_btree_balance_dirty(root, 1);
Chris Mason39279cc2007-06-12 06:35:45 -0400766 cond_resched();
767 }
Chris Mason39279cc2007-06-12 06:35:45 -0400768 mutex_unlock(&inode->i_mutex);
769out:
Chris Mason8c2383c2007-06-18 09:57:58 -0400770 kfree(pages);
Chris Mason39279cc2007-06-12 06:35:45 -0400771 if (pinned[0])
772 page_cache_release(pinned[0]);
773 if (pinned[1])
774 page_cache_release(pinned[1]);
775 *ppos = pos;
Chris Mason2ff3e9b2007-10-29 14:36:41 -0400776
777 if (num_written > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
778 err = sync_page_range(inode, inode->i_mapping,
779 start_pos, num_written);
780 if (err < 0)
781 num_written = err;
782 }
Chris Mason39279cc2007-06-12 06:35:45 -0400783 current->backing_dev_info = NULL;
Chris Mason39279cc2007-06-12 06:35:45 -0400784 return num_written ? num_written : err;
785}
786
Chris Mason39279cc2007-06-12 06:35:45 -0400787static int btrfs_sync_file(struct file *file,
788 struct dentry *dentry, int datasync)
789{
790 struct inode *inode = dentry->d_inode;
791 struct btrfs_root *root = BTRFS_I(inode)->root;
Josef Bacik15ee9bc2007-08-10 16:22:09 -0400792 int ret = 0;
Chris Mason39279cc2007-06-12 06:35:45 -0400793 struct btrfs_trans_handle *trans;
794
795 /*
Josef Bacik15ee9bc2007-08-10 16:22:09 -0400796 * check the transaction that last modified this inode
797 * and see if its already been committed
Chris Mason39279cc2007-06-12 06:35:45 -0400798 */
799 mutex_lock(&root->fs_info->fs_mutex);
Josef Bacik15ee9bc2007-08-10 16:22:09 -0400800 if (!BTRFS_I(inode)->last_trans)
801 goto out;
802 mutex_lock(&root->fs_info->trans_mutex);
803 if (BTRFS_I(inode)->last_trans <=
804 root->fs_info->last_trans_committed) {
805 BTRFS_I(inode)->last_trans = 0;
806 mutex_unlock(&root->fs_info->trans_mutex);
807 goto out;
808 }
809 mutex_unlock(&root->fs_info->trans_mutex);
810
811 /*
Chris Masona52d9a82007-08-27 16:49:44 -0400812 * ok we haven't committed the transaction yet, lets do a commit
813 */
Chris Mason39279cc2007-06-12 06:35:45 -0400814 trans = btrfs_start_transaction(root, 1);
815 if (!trans) {
816 ret = -ENOMEM;
817 goto out;
818 }
819 ret = btrfs_commit_transaction(trans, root);
Chris Mason39279cc2007-06-12 06:35:45 -0400820out:
Josef Bacik15ee9bc2007-08-10 16:22:09 -0400821 mutex_unlock(&root->fs_info->fs_mutex);
Chris Mason39279cc2007-06-12 06:35:45 -0400822 return ret > 0 ? EIO : ret;
823}
824
Chris Mason9ebefb182007-06-15 13:50:00 -0400825static struct vm_operations_struct btrfs_file_vm_ops = {
Chris Mason92fee662007-07-25 12:31:35 -0400826#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
827 .nopage = filemap_nopage,
828 .populate = filemap_populate,
829#else
830 .fault = filemap_fault,
831#endif
Chris Mason9ebefb182007-06-15 13:50:00 -0400832 .page_mkwrite = btrfs_page_mkwrite,
833};
834
835static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
836{
837 vma->vm_ops = &btrfs_file_vm_ops;
838 file_accessed(filp);
839 return 0;
840}
841
Chris Mason39279cc2007-06-12 06:35:45 -0400842struct file_operations btrfs_file_operations = {
843 .llseek = generic_file_llseek,
844 .read = do_sync_read,
Chris Mason9ebefb182007-06-15 13:50:00 -0400845 .aio_read = generic_file_aio_read,
Chris Mason39279cc2007-06-12 06:35:45 -0400846 .write = btrfs_file_write,
Chris Mason9ebefb182007-06-15 13:50:00 -0400847 .mmap = btrfs_file_mmap,
Chris Mason39279cc2007-06-12 06:35:45 -0400848 .open = generic_file_open,
Chris Mason39279cc2007-06-12 06:35:45 -0400849 .fsync = btrfs_sync_file,
Christoph Hellwig34287aa2007-09-14 10:22:47 -0400850 .unlocked_ioctl = btrfs_ioctl,
Chris Mason39279cc2007-06-12 06:35:45 -0400851#ifdef CONFIG_COMPAT
Christoph Hellwig34287aa2007-09-14 10:22:47 -0400852 .compat_ioctl = btrfs_ioctl,
Chris Mason39279cc2007-06-12 06:35:45 -0400853#endif
854};
855