blob: bf3966bccd343393656ea394f790ba79f183f93f [file] [log] [blame]
Dave Kleikampac27a0e2006-10-11 01:20:50 -07001/*
Mingming Cao617ba132006-10-11 01:20:53 -07002 * linux/fs/ext4/file.c
Dave Kleikampac27a0e2006-10-11 01:20:50 -07003 *
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/file.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
Mingming Cao617ba132006-10-11 01:20:53 -070015 * ext4 fs regular file handling primitives
Dave Kleikampac27a0e2006-10-11 01:20:50 -070016 *
17 * 64-bit file support on 64-bit platforms by Jakub Jelinek
18 * (jj@sunsite.ms.mff.cuni.cz)
19 */
20
21#include <linux/time.h>
22#include <linux/fs.h>
Mingming Caodab291a2006-10-11 01:21:01 -070023#include <linux/jbd2.h>
Theodore Ts'obc0b0d62009-06-13 10:09:48 -040024#include <linux/mount.h>
25#include <linux/path.h>
Christoph Hellwig871a2932010-03-03 09:05:07 -050026#include <linux/quotaops.h>
Christoph Hellwig3dcf5452008-04-29 18:13:32 -040027#include "ext4.h"
28#include "ext4_jbd2.h"
Dave Kleikampac27a0e2006-10-11 01:20:50 -070029#include "xattr.h"
30#include "acl.h"
31
32/*
33 * Called when an inode is released. Note that this is different
Mingming Cao617ba132006-10-11 01:20:53 -070034 * from ext4_file_open: open gets called at every open, but release
Dave Kleikampac27a0e2006-10-11 01:20:50 -070035 * gets called only when /all/ the files are closed.
36 */
Theodore Ts'oaf5bc922008-09-08 22:25:24 -040037static int ext4_release_file(struct inode *inode, struct file *filp)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070038{
Theodore Ts'o19f5fb72010-01-24 14:34:07 -050039 if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
Theodore Ts'o7d8f9f72009-02-24 08:21:14 -050040 ext4_alloc_da_blocks(inode);
Theodore Ts'o19f5fb72010-01-24 14:34:07 -050041 ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
Theodore Ts'o7d8f9f72009-02-24 08:21:14 -050042 }
Dave Kleikampac27a0e2006-10-11 01:20:50 -070043 /* if we are the last writer on the inode, drop the block reservation */
44 if ((filp->f_mode & FMODE_WRITE) &&
Aneesh Kumar K.Vd6014302009-03-27 22:36:43 -040045 (atomic_read(&inode->i_writecount) == 1) &&
46 !EXT4_I(inode)->i_reserved_data_blocks)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070047 {
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -050048 down_write(&EXT4_I(inode)->i_data_sem);
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -040049 ext4_discard_preallocations(inode);
Aneesh Kumar K.V0e855ac2008-01-28 23:58:26 -050050 up_write(&EXT4_I(inode)->i_data_sem);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070051 }
52 if (is_dx(inode) && filp->private_data)
Mingming Cao617ba132006-10-11 01:20:53 -070053 ext4_htree_free_dir_info(filp->private_data);
Dave Kleikampac27a0e2006-10-11 01:20:50 -070054
55 return 0;
56}
57
Dmitry Monakhovc2785312012-10-05 11:31:55 -040058void ext4_unwritten_wait(struct inode *inode)
Eric Sandeene9e3bce2011-02-12 08:17:34 -050059{
60 wait_queue_head_t *wq = ext4_ioend_wq(inode);
61
Dmitry Monakhove27f41e2012-09-28 23:24:52 -040062 wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0));
Eric Sandeene9e3bce2011-02-12 08:17:34 -050063}
64
65/*
66 * This tests whether the IO in question is block-aligned or not.
67 * Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
68 * are converted to written only after the IO is complete. Until they are
69 * mapped, these blocks appear as holes, so dio_zero_block() will assume that
70 * it needs to zero out portions of the start and/or end block. If 2 AIO
71 * threads are at work on the same unwritten block, they must be synchronized
72 * or one thread will zero the other's data, causing corruption.
73 */
74static int
75ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
76 unsigned long nr_segs, loff_t pos)
77{
78 struct super_block *sb = inode->i_sb;
79 int blockmask = sb->s_blocksize - 1;
80 size_t count = iov_length(iov, nr_segs);
81 loff_t final_size = pos + count;
82
83 if (pos >= inode->i_size)
84 return 0;
85
86 if ((pos & blockmask) || (final_size & blockmask))
87 return 1;
88
89 return 0;
90}
91
Dave Kleikampac27a0e2006-10-11 01:20:50 -070092static ssize_t
Zheng Liufbe10492012-07-09 16:29:29 -040093ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov,
94 unsigned long nr_segs, loff_t pos)
Dave Kleikampac27a0e2006-10-11 01:20:50 -070095{
Zheng Liu4bd809d2012-07-22 20:19:31 -040096 struct file *file = iocb->ki_filp;
97 struct inode *inode = file->f_mapping->host;
98 struct blk_plug plug;
Eric Sandeene9e3bce2011-02-12 08:17:34 -050099 int unaligned_aio = 0;
Zheng Liu85630002012-05-28 18:06:51 -0400100 ssize_t ret;
Zheng Liu4bd809d2012-07-22 20:19:31 -0400101 int overwrite = 0;
102 size_t length = iov_length(iov, nr_segs);
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700103
Zheng Liufbe10492012-07-09 16:29:29 -0400104 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
105 !is_sync_kiocb(iocb))
Eric Sandeene9e3bce2011-02-12 08:17:34 -0500106 unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos);
Eric Sandeene2b46572008-01-28 23:58:27 -0500107
Eric Sandeene9e3bce2011-02-12 08:17:34 -0500108 /* Unaligned direct AIO must be serialized; see comment above */
109 if (unaligned_aio) {
110 static unsigned long unaligned_warn_time;
111
112 /* Warn about this once per day */
113 if (printk_timed_ratelimit(&unaligned_warn_time, 60*60*24*HZ))
114 ext4_msg(inode->i_sb, KERN_WARNING,
115 "Unaligned AIO/DIO on inode %ld by %s; "
116 "performance will be poor.",
117 inode->i_ino, current->comm);
118 mutex_lock(ext4_aio_mutex(inode));
Dmitry Monakhove27f41e2012-09-28 23:24:52 -0400119 ext4_unwritten_wait(inode);
Eric Sandeene9e3bce2011-02-12 08:17:34 -0500120 }
121
Zheng Liu4bd809d2012-07-22 20:19:31 -0400122 BUG_ON(iocb->ki_pos != pos);
123
124 mutex_lock(&inode->i_mutex);
125 blk_start_plug(&plug);
126
127 iocb->private = &overwrite;
128
129 /* check whether we do a DIO overwrite or not */
130 if (ext4_should_dioread_nolock(inode) && !unaligned_aio &&
131 !file->f_mapping->nrpages && pos + length <= i_size_read(inode)) {
132 struct ext4_map_blocks map;
133 unsigned int blkbits = inode->i_blkbits;
134 int err, len;
135
136 map.m_lblk = pos >> blkbits;
137 map.m_len = (EXT4_BLOCK_ALIGN(pos + length, blkbits) >> blkbits)
138 - map.m_lblk;
139 len = map.m_len;
140
141 err = ext4_map_blocks(NULL, inode, &map, 0);
142 /*
143 * 'err==len' means that all of blocks has been preallocated no
144 * matter they are initialized or not. For excluding
145 * uninitialized extents, we need to check m_flags. There are
146 * two conditions that indicate for initialized extents.
147 * 1) If we hit extent cache, EXT4_MAP_MAPPED flag is returned;
148 * 2) If we do a real lookup, non-flags are returned.
149 * So we should check these two conditions.
150 */
151 if (err == len && (map.m_flags & EXT4_MAP_MAPPED))
152 overwrite = 1;
153 }
154
155 ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
156 mutex_unlock(&inode->i_mutex);
157
158 if (ret > 0 || ret == -EIOCBQUEUED) {
159 ssize_t err;
160
161 err = generic_write_sync(file, pos, ret);
162 if (err < 0 && ret > 0)
163 ret = err;
164 }
165 blk_finish_plug(&plug);
Eric Sandeene9e3bce2011-02-12 08:17:34 -0500166
167 if (unaligned_aio)
168 mutex_unlock(ext4_aio_mutex(inode));
169
170 return ret;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700171}
172
Zheng Liufbe10492012-07-09 16:29:29 -0400173static ssize_t
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -0400174ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
175 unsigned long nr_segs, loff_t pos)
176{
177 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -0400178 ssize_t ret;
179
180 /*
181 * If we have encountered a bitmap-format file, the size limit
182 * is smaller than s_maxbytes, which is for extent-mapped files.
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400183 */
184
185 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
186 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
Theodore Ts'o8aefcd52011-01-10 12:29:43 -0500187 size_t length = iov_length(iov, nr_segs);
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400188
189 if ((pos > sbi->s_bitmap_maxbytes ||
190 (pos == sbi->s_bitmap_maxbytes && length > 0)))
191 return -EFBIG;
192
193 if (pos + length > sbi->s_bitmap_maxbytes) {
194 nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
195 sbi->s_bitmap_maxbytes - pos);
196 }
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400197 }
198
Zheng Liufbe10492012-07-09 16:29:29 -0400199 if (unlikely(iocb->ki_filp->f_flags & O_DIRECT))
200 ret = ext4_file_dio_write(iocb, iov, nr_segs, pos);
201 else
202 ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
Theodore Ts'o8aefcd52011-01-10 12:29:43 -0500203
204 return ret;
205}
206
207static const struct vm_operations_struct ext4_file_vm_ops = {
208 .fault = filemap_fault,
209 .page_mkwrite = ext4_page_mkwrite,
Konstantin Khlebnikov0b173bc2012-10-08 16:28:46 -0700210 .remap_pages = generic_file_remap_pages,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700211};
212
213static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
214{
215 struct address_space *mapping = file->f_mapping;
216
217 if (!mapping->a_ops->readpage)
218 return -ENOEXEC;
219 file_accessed(file);
220 vma->vm_ops = &ext4_file_vm_ops;
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700221 return 0;
222}
223
224static int ext4_file_open(struct inode * inode, struct file * filp)
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400225{
226 struct super_block *sb = inode->i_sb;
227 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
228 struct ext4_inode_info *ei = EXT4_I(inode);
229 struct vfsmount *mnt = filp->f_path.mnt;
230 struct path path;
231 char buf[64], *cp;
232
233 if (unlikely(!(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED) &&
234 !(sb->s_flags & MS_RDONLY))) {
235 sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
236 /*
237 * Sample where the filesystem has been mounted and
238 * store it in the superblock for sysadmin convenience
239 * when trying to sort through large numbers of block
240 * devices or filesystem images.
241 */
242 memset(buf, 0, sizeof(buf));
Al Viro38991672010-01-23 20:10:29 -0500243 path.mnt = mnt;
244 path.dentry = mnt->mnt_root;
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400245 cp = d_path(&path, buf, sizeof(buf));
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400246 if (!IS_ERR(cp)) {
Jan Kara044ce472012-07-22 20:31:31 -0400247 handle_t *handle;
248 int err;
249
250 handle = ext4_journal_start_sb(sb, 1);
251 if (IS_ERR(handle))
252 return PTR_ERR(handle);
253 err = ext4_journal_get_write_access(handle, sbi->s_sbh);
254 if (err) {
255 ext4_journal_stop(handle);
256 return err;
257 }
Darrick J. Wongcf803902011-10-25 09:18:41 -0400258 strlcpy(sbi->s_es->s_last_mounted, cp,
259 sizeof(sbi->s_es->s_last_mounted));
Jan Kara044ce472012-07-22 20:31:31 -0400260 ext4_handle_dirty_super(handle, sb);
261 ext4_journal_stop(handle);
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400262 }
263 }
Theodore Ts'o8aefcd52011-01-10 12:29:43 -0500264 /*
265 * Set up the jbd2_inode if we are opening the inode for
266 * writing and the journal is present
267 */
268 if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) {
269 struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL);
270
271 spin_lock(&inode->i_lock);
272 if (!ei->jinode) {
273 if (!jinode) {
274 spin_unlock(&inode->i_lock);
275 return -ENOMEM;
276 }
277 ei->jinode = jinode;
278 jbd2_journal_init_jbd_inode(ei->jinode, inode);
279 jinode = NULL;
280 }
281 spin_unlock(&inode->i_lock);
282 if (unlikely(jinode != NULL))
283 jbd2_free_inode(jinode);
284 }
Christoph Hellwig907f4552010-03-03 09:05:06 -0500285 return dquot_file_open(inode, filp);
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400286}
287
Toshiyuki Okajimae0d10bf2010-10-27 21:30:06 -0400288/*
Eric Sandeenec7268c2012-04-30 13:14:03 -0500289 * ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
290 * by calling generic_file_llseek_size() with the appropriate maxbytes
291 * value for each.
Toshiyuki Okajimae0d10bf2010-10-27 21:30:06 -0400292 */
293loff_t ext4_llseek(struct file *file, loff_t offset, int origin)
294{
295 struct inode *inode = file->f_mapping->host;
296 loff_t maxbytes;
297
298 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
299 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
300 else
301 maxbytes = inode->i_sb->s_maxbytes;
Toshiyuki Okajimae0d10bf2010-10-27 21:30:06 -0400302
Eric Sandeene8b96eb2012-04-30 13:11:29 -0500303 return generic_file_llseek_size(file, offset, origin,
304 maxbytes, i_size_read(inode));
Toshiyuki Okajimae0d10bf2010-10-27 21:30:06 -0400305}
306
Mingming Cao617ba132006-10-11 01:20:53 -0700307const struct file_operations ext4_file_operations = {
Toshiyuki Okajimae0d10bf2010-10-27 21:30:06 -0400308 .llseek = ext4_llseek,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700309 .read = do_sync_read,
310 .write = do_sync_write,
311 .aio_read = generic_file_aio_read,
Mingming Cao617ba132006-10-11 01:20:53 -0700312 .aio_write = ext4_file_write,
Andi Kleen5cdd7b22008-04-29 22:03:54 -0400313 .unlocked_ioctl = ext4_ioctl,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700314#ifdef CONFIG_COMPAT
Mingming Cao617ba132006-10-11 01:20:53 -0700315 .compat_ioctl = ext4_compat_ioctl,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700316#endif
Aneesh Kumar K.V2e9ee852008-07-11 19:27:31 -0400317 .mmap = ext4_file_mmap,
Theodore Ts'obc0b0d62009-06-13 10:09:48 -0400318 .open = ext4_file_open,
Mingming Cao617ba132006-10-11 01:20:53 -0700319 .release = ext4_release_file,
320 .fsync = ext4_sync_file,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700321 .splice_read = generic_file_splice_read,
322 .splice_write = generic_file_splice_write,
Christoph Hellwig2fe17c12011-01-14 13:07:43 +0100323 .fallocate = ext4_fallocate,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700324};
325
Arjan van de Ven754661f2007-02-12 00:55:38 -0800326const struct inode_operations ext4_file_inode_operations = {
Mingming Cao617ba132006-10-11 01:20:53 -0700327 .setattr = ext4_setattr,
Mingming Cao3e3398a2008-07-11 19:27:31 -0400328 .getattr = ext4_getattr,
Theodore Ts'o03010a32008-10-10 20:02:48 -0400329#ifdef CONFIG_EXT4_FS_XATTR
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700330 .setxattr = generic_setxattr,
331 .getxattr = generic_getxattr,
Mingming Cao617ba132006-10-11 01:20:53 -0700332 .listxattr = ext4_listxattr,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700333 .removexattr = generic_removexattr,
334#endif
Christoph Hellwig4e34e712011-07-23 17:37:31 +0200335 .get_acl = ext4_get_acl,
Eric Sandeen6873fa02008-10-07 00:46:36 -0400336 .fiemap = ext4_fiemap,
Dave Kleikampac27a0e2006-10-11 01:20:50 -0700337};
338