ARM: S5PV310: Add SMDKC210 board support file
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / reiserfs / file.c
blob6846371498b685becc1ff8eba16b2e62933c57d5
1 /*
2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3 */
5 #include <linux/time.h>
6 #include <linux/reiserfs_fs.h>
7 #include <linux/reiserfs_acl.h>
8 #include <linux/reiserfs_xattr.h>
9 #include <asm/uaccess.h>
10 #include <linux/pagemap.h>
11 #include <linux/swap.h>
12 #include <linux/writeback.h>
13 #include <linux/blkdev.h>
14 #include <linux/buffer_head.h>
15 #include <linux/quotaops.h>
18 ** We pack the tails of files on file close, not at the time they are written.
19 ** This implies an unnecessary copy of the tail and an unnecessary indirect item
20 ** insertion/balancing, for files that are written in one write.
21 ** It avoids unnecessary tail packings (balances) for files that are written in
22 ** multiple writes and are small enough to have tails.
24 ** file_release is called by the VFS layer when the file is closed. If
25 ** this is the last open file descriptor, and the file
26 ** small enough to have a tail, and the tail is currently in an
27 ** unformatted node, the tail is converted back into a direct item.
29 ** We use reiserfs_truncate_file to pack the tail, since it already has
30 ** all the conditions coded.
32 static int reiserfs_file_release(struct inode *inode, struct file *filp)
35 struct reiserfs_transaction_handle th;
36 int err;
37 int jbegin_failure = 0;
39 BUG_ON(!S_ISREG(inode->i_mode));
41 if (atomic_add_unless(&REISERFS_I(inode)->openers, -1, 1))
42 return 0;
44 mutex_lock(&(REISERFS_I(inode)->tailpack));
46 if (!atomic_dec_and_test(&REISERFS_I(inode)->openers)) {
47 mutex_unlock(&(REISERFS_I(inode)->tailpack));
48 return 0;
51 /* fast out for when nothing needs to be done */
52 if ((!(REISERFS_I(inode)->i_flags & i_pack_on_close_mask) ||
53 !tail_has_to_be_packed(inode)) &&
54 REISERFS_I(inode)->i_prealloc_count <= 0) {
55 mutex_unlock(&(REISERFS_I(inode)->tailpack));
56 return 0;
59 reiserfs_write_lock(inode->i_sb);
60 /* freeing preallocation only involves relogging blocks that
61 * are already in the current transaction. preallocation gets
62 * freed at the end of each transaction, so it is impossible for
63 * us to log any additional blocks (including quota blocks)
65 err = journal_begin(&th, inode->i_sb, 1);
66 if (err) {
67 /* uh oh, we can't allow the inode to go away while there
68 * is still preallocation blocks pending. Try to join the
69 * aborted transaction
71 jbegin_failure = err;
72 err = journal_join_abort(&th, inode->i_sb, 1);
74 if (err) {
75 /* hmpf, our choices here aren't good. We can pin the inode
76 * which will disallow unmount from every happening, we can
77 * do nothing, which will corrupt random memory on unmount,
78 * or we can forcibly remove the file from the preallocation
79 * list, which will leak blocks on disk. Lets pin the inode
80 * and let the admin know what is going on.
82 igrab(inode);
83 reiserfs_warning(inode->i_sb, "clm-9001",
84 "pinning inode %lu because the "
85 "preallocation can't be freed",
86 inode->i_ino);
87 goto out;
90 reiserfs_update_inode_transaction(inode);
92 #ifdef REISERFS_PREALLOCATE
93 reiserfs_discard_prealloc(&th, inode);
94 #endif
95 err = journal_end(&th, inode->i_sb, 1);
97 /* copy back the error code from journal_begin */
98 if (!err)
99 err = jbegin_failure;
101 if (!err &&
102 (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) &&
103 tail_has_to_be_packed(inode)) {
105 /* if regular file is released by last holder and it has been
106 appended (we append by unformatted node only) or its direct
107 item(s) had to be converted, then it may have to be
108 indirect2direct converted */
109 err = reiserfs_truncate_file(inode, 0);
111 out:
112 reiserfs_write_unlock(inode->i_sb);
113 mutex_unlock(&(REISERFS_I(inode)->tailpack));
114 return err;
117 static int reiserfs_file_open(struct inode *inode, struct file *file)
119 int err = dquot_file_open(inode, file);
120 if (!atomic_inc_not_zero(&REISERFS_I(inode)->openers)) {
121 /* somebody might be tailpacking on final close; wait for it */
122 mutex_lock(&(REISERFS_I(inode)->tailpack));
123 atomic_inc(&REISERFS_I(inode)->openers);
124 mutex_unlock(&(REISERFS_I(inode)->tailpack));
126 return err;
129 static void reiserfs_vfs_truncate_file(struct inode *inode)
131 mutex_lock(&(REISERFS_I(inode)->tailpack));
132 reiserfs_truncate_file(inode, 1);
133 mutex_unlock(&(REISERFS_I(inode)->tailpack));
136 /* Sync a reiserfs file. */
139 * FIXME: sync_mapping_buffers() never has anything to sync. Can
140 * be removed...
143 static int reiserfs_sync_file(struct file *filp, int datasync)
145 struct inode *inode = filp->f_mapping->host;
146 int err;
147 int barrier_done;
149 BUG_ON(!S_ISREG(inode->i_mode));
150 err = sync_mapping_buffers(inode->i_mapping);
151 reiserfs_write_lock(inode->i_sb);
152 barrier_done = reiserfs_commit_for_inode(inode);
153 reiserfs_write_unlock(inode->i_sb);
154 if (barrier_done != 1 && reiserfs_barrier_flush(inode->i_sb))
155 blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL,
156 BLKDEV_IFL_WAIT);
157 if (barrier_done < 0)
158 return barrier_done;
159 return (err < 0) ? -EIO : 0;
162 /* taken fs/buffer.c:__block_commit_write */
163 int reiserfs_commit_page(struct inode *inode, struct page *page,
164 unsigned from, unsigned to)
166 unsigned block_start, block_end;
167 int partial = 0;
168 unsigned blocksize;
169 struct buffer_head *bh, *head;
170 unsigned long i_size_index = inode->i_size >> PAGE_CACHE_SHIFT;
171 int new;
172 int logit = reiserfs_file_data_log(inode);
173 struct super_block *s = inode->i_sb;
174 int bh_per_page = PAGE_CACHE_SIZE / s->s_blocksize;
175 struct reiserfs_transaction_handle th;
176 int ret = 0;
178 th.t_trans_id = 0;
179 blocksize = 1 << inode->i_blkbits;
181 if (logit) {
182 reiserfs_write_lock(s);
183 ret = journal_begin(&th, s, bh_per_page + 1);
184 if (ret)
185 goto drop_write_lock;
186 reiserfs_update_inode_transaction(inode);
188 for (bh = head = page_buffers(page), block_start = 0;
189 bh != head || !block_start;
190 block_start = block_end, bh = bh->b_this_page) {
192 new = buffer_new(bh);
193 clear_buffer_new(bh);
194 block_end = block_start + blocksize;
195 if (block_end <= from || block_start >= to) {
196 if (!buffer_uptodate(bh))
197 partial = 1;
198 } else {
199 set_buffer_uptodate(bh);
200 if (logit) {
201 reiserfs_prepare_for_journal(s, bh, 1);
202 journal_mark_dirty(&th, s, bh);
203 } else if (!buffer_dirty(bh)) {
204 mark_buffer_dirty(bh);
205 /* do data=ordered on any page past the end
206 * of file and any buffer marked BH_New.
208 if (reiserfs_data_ordered(inode->i_sb) &&
209 (new || page->index >= i_size_index)) {
210 reiserfs_add_ordered_list(inode, bh);
215 if (logit) {
216 ret = journal_end(&th, s, bh_per_page + 1);
217 drop_write_lock:
218 reiserfs_write_unlock(s);
221 * If this is a partial write which happened to make all buffers
222 * uptodate then we can optimize away a bogus readpage() for
223 * the next read(). Here we 'discover' whether the page went
224 * uptodate as a result of this (potentially partial) write.
226 if (!partial)
227 SetPageUptodate(page);
228 return ret;
231 /* Write @count bytes at position @ppos in a file indicated by @file
232 from the buffer @buf.
234 generic_file_write() is only appropriate for filesystems that are not seeking to optimize performance and want
235 something simple that works. It is not for serious use by general purpose filesystems, excepting the one that it was
236 written for (ext2/3). This is for several reasons:
238 * It has no understanding of any filesystem specific optimizations.
240 * It enters the filesystem repeatedly for each page that is written.
242 * It depends on reiserfs_get_block() function which if implemented by reiserfs performs costly search_by_key
243 * operation for each page it is supplied with. By contrast reiserfs_file_write() feeds as much as possible at a time
244 * to reiserfs which allows for fewer tree traversals.
246 * Each indirect pointer insertion takes a lot of cpu, because it involves memory moves inside of blocks.
248 * Asking the block allocation code for blocks one at a time is slightly less efficient.
250 All of these reasons for not using only generic file write were understood back when reiserfs was first miscoded to
251 use it, but we were in a hurry to make code freeze, and so it couldn't be revised then. This new code should make
252 things right finally.
254 Future Features: providing search_by_key with hints.
257 static ssize_t reiserfs_file_write(struct file *file, /* the file we are going to write into */
258 const char __user * buf, /* pointer to user supplied data
259 (in userspace) */
260 size_t count, /* amount of bytes to write */
261 loff_t * ppos /* pointer to position in file that we start writing at. Should be updated to
262 * new current position before returning. */
265 struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to.
266 /* To simplify coding at this time, we store
267 locked pages in array for now */
268 struct reiserfs_transaction_handle th;
269 th.t_trans_id = 0;
271 /* If a filesystem is converted from 3.5 to 3.6, we'll have v3.5 items
272 * lying around (most of the disk, in fact). Despite the filesystem
273 * now being a v3.6 format, the old items still can't support large
274 * file sizes. Catch this case here, as the rest of the VFS layer is
275 * oblivious to the different limitations between old and new items.
276 * reiserfs_setattr catches this for truncates. This chunk is lifted
277 * from generic_write_checks. */
278 if (get_inode_item_key_version (inode) == KEY_FORMAT_3_5 &&
279 *ppos + count > MAX_NON_LFS) {
280 if (*ppos >= MAX_NON_LFS) {
281 return -EFBIG;
283 if (count > MAX_NON_LFS - (unsigned long)*ppos)
284 count = MAX_NON_LFS - (unsigned long)*ppos;
287 return do_sync_write(file, buf, count, ppos);
290 const struct file_operations reiserfs_file_operations = {
291 .read = do_sync_read,
292 .write = reiserfs_file_write,
293 .unlocked_ioctl = reiserfs_ioctl,
294 #ifdef CONFIG_COMPAT
295 .compat_ioctl = reiserfs_compat_ioctl,
296 #endif
297 .mmap = generic_file_mmap,
298 .open = reiserfs_file_open,
299 .release = reiserfs_file_release,
300 .fsync = reiserfs_sync_file,
301 .aio_read = generic_file_aio_read,
302 .aio_write = generic_file_aio_write,
303 .splice_read = generic_file_splice_read,
304 .splice_write = generic_file_splice_write,
305 .llseek = generic_file_llseek,
308 const struct inode_operations reiserfs_file_inode_operations = {
309 .truncate = reiserfs_vfs_truncate_file,
310 .setattr = reiserfs_setattr,
311 .setxattr = reiserfs_setxattr,
312 .getxattr = reiserfs_getxattr,
313 .listxattr = reiserfs_listxattr,
314 .removexattr = reiserfs_removexattr,
315 .permission = reiserfs_permission,