CIFS: Fix too big maxBuf size for SMB3 mounts
[linux-3.10.git] / fs / nilfs2 / file.c
1 /*
2  * file.c - NILFS regular file handling primitives including fsync().
3  *
4  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Amagai Yoshiji <amagai@osrg.net>,
21  *            Ryusuke Konishi <ryusuke@osrg.net>
22  */
23
24 #include <linux/fs.h>
25 #include <linux/mm.h>
26 #include <linux/writeback.h>
27 #include "nilfs.h"
28 #include "segment.h"
29
30 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
31 {
32         /*
33          * Called from fsync() system call
34          * This is the only entry point that can catch write and synch
35          * timing for both data blocks and intermediate blocks.
36          *
37          * This function should be implemented when the writeback function
38          * will be implemented.
39          */
40         struct the_nilfs *nilfs;
41         struct inode *inode = file->f_mapping->host;
42         int err;
43
44         err = filemap_write_and_wait_range(inode->i_mapping, start, end);
45         if (err)
46                 return err;
47         mutex_lock(&inode->i_mutex);
48
49         if (nilfs_inode_dirty(inode)) {
50                 if (datasync)
51                         err = nilfs_construct_dsync_segment(inode->i_sb, inode,
52                                                             0, LLONG_MAX);
53                 else
54                         err = nilfs_construct_segment(inode->i_sb);
55         }
56         mutex_unlock(&inode->i_mutex);
57
58         nilfs = inode->i_sb->s_fs_info;
59         if (!err && nilfs_test_opt(nilfs, BARRIER)) {
60                 err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL);
61                 if (err != -EIO)
62                         err = 0;
63         }
64         return err;
65 }
66
67 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
68 {
69         struct page *page = vmf->page;
70         struct inode *inode = file_inode(vma->vm_file);
71         struct nilfs_transaction_info ti;
72         int ret = 0;
73
74         if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
75                 return VM_FAULT_SIGBUS; /* -ENOSPC */
76
77         sb_start_pagefault(inode->i_sb);
78         lock_page(page);
79         if (page->mapping != inode->i_mapping ||
80             page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
81                 unlock_page(page);
82                 ret = -EFAULT;  /* make the VM retry the fault */
83                 goto out;
84         }
85
86         /*
87          * check to see if the page is mapped already (no holes)
88          */
89         if (PageMappedToDisk(page))
90                 goto mapped;
91
92         if (page_has_buffers(page)) {
93                 struct buffer_head *bh, *head;
94                 int fully_mapped = 1;
95
96                 bh = head = page_buffers(page);
97                 do {
98                         if (!buffer_mapped(bh)) {
99                                 fully_mapped = 0;
100                                 break;
101                         }
102                 } while (bh = bh->b_this_page, bh != head);
103
104                 if (fully_mapped) {
105                         SetPageMappedToDisk(page);
106                         goto mapped;
107                 }
108         }
109         unlock_page(page);
110
111         /*
112          * fill hole blocks
113          */
114         ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
115         /* never returns -ENOMEM, but may return -ENOSPC */
116         if (unlikely(ret))
117                 goto out;
118
119         file_update_time(vma->vm_file);
120         ret = __block_page_mkwrite(vma, vmf, nilfs_get_block);
121         if (ret) {
122                 nilfs_transaction_abort(inode->i_sb);
123                 goto out;
124         }
125         nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
126         nilfs_transaction_commit(inode->i_sb);
127
128  mapped:
129         wait_for_stable_page(page);
130  out:
131         sb_end_pagefault(inode->i_sb);
132         return block_page_mkwrite_return(ret);
133 }
134
135 static const struct vm_operations_struct nilfs_file_vm_ops = {
136         .fault          = filemap_fault,
137         .page_mkwrite   = nilfs_page_mkwrite,
138         .remap_pages    = generic_file_remap_pages,
139 };
140
141 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma)
142 {
143         file_accessed(file);
144         vma->vm_ops = &nilfs_file_vm_ops;
145         return 0;
146 }
147
148 /*
149  * We have mostly NULL's here: the current defaults are ok for
150  * the nilfs filesystem.
151  */
152 const struct file_operations nilfs_file_operations = {
153         .llseek         = generic_file_llseek,
154         .read           = do_sync_read,
155         .write          = do_sync_write,
156         .aio_read       = generic_file_aio_read,
157         .aio_write      = generic_file_aio_write,
158         .unlocked_ioctl = nilfs_ioctl,
159 #ifdef CONFIG_COMPAT
160         .compat_ioctl   = nilfs_compat_ioctl,
161 #endif  /* CONFIG_COMPAT */
162         .mmap           = nilfs_file_mmap,
163         .open           = generic_file_open,
164         /* .release     = nilfs_release_file, */
165         .fsync          = nilfs_sync_file,
166         .splice_read    = generic_file_splice_read,
167 };
168
169 const struct inode_operations nilfs_file_inode_operations = {
170         .setattr        = nilfs_setattr,
171         .permission     = nilfs_permission,
172         .fiemap         = nilfs_fiemap,
173 };
174
175 /* end of file */