- size_t already_written = 0; // Number of bytes already written to the file.
- loff_t pos; // Current position in the file.
- size_t res; // return value of various functions that we call.
- struct inode *inode = file->f_dentry->d_inode; // Inode of the file that we are writing to.
- /* To simplify coding at this time, we store
- locked pages in array for now */
- struct page * prepared_pages[REISERFS_WRITE_PAGES_AT_A_TIME];
- struct reiserfs_transaction_handle th;
- th.t_trans_id = 0;
-
- if ( file->f_flags & O_DIRECT) { // Direct IO needs treatment
- int result, after_file_end = 0;
- if ( (*ppos + count >= inode->i_size) || (file->f_flags & O_APPEND) ) {
- /* If we are appending a file, we need to put this savelink in here.
- If we will crash while doing direct io, finish_unfinished will
- cut the garbage from the file end. */
- reiserfs_write_lock(inode->i_sb);
- journal_begin(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT );
- reiserfs_update_inode_transaction(inode);
- add_save_link (&th, inode, 1 /* Truncate */);
- journal_end(&th, inode->i_sb, JOURNAL_PER_BALANCE_CNT );
- reiserfs_write_unlock(inode->i_sb);
- after_file_end = 1;
- }
- result = generic_file_write(file, buf, count, ppos);
-
- if ( after_file_end ) { /* Now update i_size and remove the savelink */
- struct reiserfs_transaction_handle th;
- reiserfs_write_lock(inode->i_sb);
- journal_begin(&th, inode->i_sb, 1);
- reiserfs_update_inode_transaction(inode);
- reiserfs_update_sd(&th, inode);
- journal_end(&th, inode->i_sb, 1);
- remove_save_link (inode, 1/* truncate */);
- reiserfs_write_unlock(inode->i_sb);
- }
-
- return result;
- }
-
- if ( unlikely((ssize_t) count < 0 ))
- return -EINVAL;
-
- if (unlikely(!access_ok(VERIFY_READ, buf, count)))
- return -EFAULT;
-
- down(&inode->i_sem); // locks the entire file for just us
-
- pos = *ppos;
-
- /* Check if we can write to specified region of file, file
- is not overly big and this kind of stuff. Adjust pos and
- count, if needed */
- res = generic_write_checks(file, &pos, &count, 0);
- if (res)
- goto out;
-
- if ( count == 0 )
- goto out;
-
- res = remove_suid(file->f_dentry);
- if (res)
- goto out;
-
- inode_update_time(inode, 1); /* Both mtime and ctime */
-
- // Ok, we are done with all the checks.
-
- // Now we should start real work
-
- /* If we are going to write past the file's packed tail or if we are going
- to overwrite part of the tail, we need that tail to be converted into
- unformatted node */
- res = reiserfs_check_for_tail_and_convert( inode, pos, count);
- if (res)
- goto out;
-
- while ( count > 0) {
- /* This is the main loop in which we running until some error occures
- or until we write all of the data. */
- int num_pages;/* amount of pages we are going to write this iteration */
- int write_bytes; /* amount of bytes to write during this iteration */
- int blocks_to_allocate; /* how much blocks we need to allocate for
- this iteration */
-
- /* (pos & (PAGE_CACHE_SIZE-1)) is an idiom for offset into a page of pos*/
- num_pages = !!((pos+count) & (PAGE_CACHE_SIZE - 1)) + /* round up partial
- pages */
- ((count + (pos & (PAGE_CACHE_SIZE-1))) >> PAGE_CACHE_SHIFT);
- /* convert size to amount of
- pages */
- reiserfs_write_lock(inode->i_sb);
- if ( num_pages > REISERFS_WRITE_PAGES_AT_A_TIME
- || num_pages > reiserfs_can_fit_pages(inode->i_sb) ) {
- /* If we were asked to write more data than we want to or if there
- is not that much space, then we shorten amount of data to write
- for this iteration. */
- num_pages = min_t(int, REISERFS_WRITE_PAGES_AT_A_TIME, reiserfs_can_fit_pages(inode->i_sb));
- /* Also we should not forget to set size in bytes accordingly */
- write_bytes = (num_pages << PAGE_CACHE_SHIFT) -
- (pos & (PAGE_CACHE_SIZE-1));
- /* If position is not on the
- start of the page, we need
- to substract the offset
- within page */
- } else
- write_bytes = count;
-
- /* reserve the blocks to be allocated later, so that later on
- we still have the space to write the blocks to */
- reiserfs_claim_blocks_to_be_allocated(inode->i_sb, num_pages << (PAGE_CACHE_SHIFT - inode->i_blkbits));
- reiserfs_write_unlock(inode->i_sb);
-
- if ( !num_pages ) { /* If we do not have enough space even for */
- res = -ENOSPC; /* single page, return -ENOSPC */
- if ( pos > (inode->i_size & (inode->i_sb->s_blocksize-1)))
- break; // In case we are writing past the file end, break.
- // Otherwise we are possibly overwriting the file, so
- // let's set write size to be equal or less than blocksize.
- // This way we get it correctly for file holes.
- // But overwriting files on absolutelly full volumes would not
- // be very efficient. Well, people are not supposed to fill
- // 100% of disk space anyway.
- write_bytes = min_t(int, count, inode->i_sb->s_blocksize - (pos & (inode->i_sb->s_blocksize - 1)));
- num_pages = 1;
- // No blocks were claimed before, so do it now.
- reiserfs_claim_blocks_to_be_allocated(inode->i_sb, 1 << (PAGE_CACHE_SHIFT - inode->i_blkbits));
+ size_t already_written = 0; // Number of bytes already written to the file.
+ loff_t pos; // Current position in the file.
+ ssize_t res; // return value of various functions that we call.
+ int err = 0;
+ struct inode *inode = file->f_path.dentry->d_inode; // Inode of the file that we are writing to.
+ /* To simplify coding at this time, we store
+ locked pages in array for now */
+ struct page *prepared_pages[REISERFS_WRITE_PAGES_AT_A_TIME];
+ struct reiserfs_transaction_handle th;
+ th.t_trans_id = 0;
+
+ /* If a filesystem is converted from 3.5 to 3.6, we'll have v3.5 items
+ * lying around (most of the disk, in fact). Despite the filesystem
+ * now being a v3.6 format, the old items still can't support large
+ * file sizes. Catch this case here, as the rest of the VFS layer is
+ * oblivious to the different limitations between old and new items.
+ * reiserfs_setattr catches this for truncates. This chunk is lifted
+ * from generic_write_checks. */
+ if (get_inode_item_key_version (inode) == KEY_FORMAT_3_5 &&
+ *ppos + count > MAX_NON_LFS) {
+ if (*ppos >= MAX_NON_LFS) {
+ send_sig(SIGXFSZ, current, 0);
+ return -EFBIG;
+ }
+ if (count > MAX_NON_LFS - (unsigned long)*ppos)
+ count = MAX_NON_LFS - (unsigned long)*ppos;