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Commit | Line | Data |
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ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/file.c |
ac27a0ec DK |
3 | * |
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 | * | |
617ba13b | 15 | * ext4 fs regular file handling primitives |
ac27a0ec DK |
16 | * |
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> | |
dab291af | 23 | #include <linux/jbd2.h> |
bc0b0d6d TT |
24 | #include <linux/mount.h> |
25 | #include <linux/path.h> | |
871a2931 | 26 | #include <linux/quotaops.h> |
3dcf5451 CH |
27 | #include "ext4.h" |
28 | #include "ext4_jbd2.h" | |
ac27a0ec DK |
29 | #include "xattr.h" |
30 | #include "acl.h" | |
31 | ||
32 | /* | |
33 | * Called when an inode is released. Note that this is different | |
617ba13b | 34 | * from ext4_file_open: open gets called at every open, but release |
ac27a0ec DK |
35 | * gets called only when /all/ the files are closed. |
36 | */ | |
af5bc92d | 37 | static int ext4_release_file(struct inode *inode, struct file *filp) |
ac27a0ec | 38 | { |
19f5fb7a | 39 | if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) { |
7d8f9f7d | 40 | ext4_alloc_da_blocks(inode); |
19f5fb7a | 41 | ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); |
7d8f9f7d | 42 | } |
ac27a0ec DK |
43 | /* if we are the last writer on the inode, drop the block reservation */ |
44 | if ((filp->f_mode & FMODE_WRITE) && | |
d6014301 AK |
45 | (atomic_read(&inode->i_writecount) == 1) && |
46 | !EXT4_I(inode)->i_reserved_data_blocks) | |
ac27a0ec | 47 | { |
0e855ac8 | 48 | down_write(&EXT4_I(inode)->i_data_sem); |
c2ea3fde | 49 | ext4_discard_preallocations(inode); |
0e855ac8 | 50 | up_write(&EXT4_I(inode)->i_data_sem); |
ac27a0ec DK |
51 | } |
52 | if (is_dx(inode) && filp->private_data) | |
617ba13b | 53 | ext4_htree_free_dir_info(filp->private_data); |
ac27a0ec DK |
54 | |
55 | return 0; | |
56 | } | |
57 | ||
c278531d | 58 | void ext4_unwritten_wait(struct inode *inode) |
e9e3bcec ES |
59 | { |
60 | wait_queue_head_t *wq = ext4_ioend_wq(inode); | |
61 | ||
e27f41e1 | 62 | wait_event(*wq, (atomic_read(&EXT4_I(inode)->i_unwritten) == 0)); |
e9e3bcec ES |
63 | } |
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 | */ | |
74 | static int | |
75 | ext4_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 | ||
ac27a0ec | 92 | static ssize_t |
fbe10494 ZL |
93 | ext4_file_dio_write(struct kiocb *iocb, const struct iovec *iov, |
94 | unsigned long nr_segs, loff_t pos) | |
ac27a0ec | 95 | { |
4bd809db ZL |
96 | struct file *file = iocb->ki_filp; |
97 | struct inode *inode = file->f_mapping->host; | |
98 | struct blk_plug plug; | |
e9e3bcec | 99 | int unaligned_aio = 0; |
8563000d | 100 | ssize_t ret; |
4bd809db ZL |
101 | int overwrite = 0; |
102 | size_t length = iov_length(iov, nr_segs); | |
ac27a0ec | 103 | |
fbe10494 ZL |
104 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) && |
105 | !is_sync_kiocb(iocb)) | |
e9e3bcec | 106 | unaligned_aio = ext4_unaligned_aio(inode, iov, nr_segs, pos); |
e2b46574 | 107 | |
e9e3bcec ES |
108 | /* 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)); | |
e27f41e1 | 119 | ext4_unwritten_wait(inode); |
e9e3bcec ES |
120 | } |
121 | ||
4bd809db ZL |
122 | 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); | |
e9e3bcec ES |
166 | |
167 | if (unaligned_aio) | |
168 | mutex_unlock(ext4_aio_mutex(inode)); | |
169 | ||
170 | return ret; | |
ac27a0ec DK |
171 | } |
172 | ||
ac27a0ec | 173 | static ssize_t |
617ba13b | 174 | ext4_file_write(struct kiocb *iocb, const struct iovec *iov, |
ac27a0ec DK |
175 | unsigned long nr_segs, loff_t pos) |
176 | { | |
0d34ec62 | 177 | struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; |
8563000d | 178 | ssize_t ret; |
ac27a0ec | 179 | |
e2b46574 ES |
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. | |
183 | */ | |
184 | ||
12e9b892 | 185 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
e2b46574 ES |
186 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
187 | size_t length = iov_length(iov, nr_segs); | |
ac27a0ec | 188 | |
d889dc83 TO |
189 | if ((pos > sbi->s_bitmap_maxbytes || |
190 | (pos == sbi->s_bitmap_maxbytes && length > 0))) | |
e2b46574 ES |
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 | } | |
197 | } | |
198 | ||
fbe10494 ZL |
199 | 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); | |
e9e3bcec ES |
203 | |
204 | return ret; | |
ac27a0ec DK |
205 | } |
206 | ||
f0f37e2f | 207 | static const struct vm_operations_struct ext4_file_vm_ops = { |
2e9ee850 AK |
208 | .fault = filemap_fault, |
209 | .page_mkwrite = ext4_page_mkwrite, | |
0b173bc4 | 210 | .remap_pages = generic_file_remap_pages, |
2e9ee850 AK |
211 | }; |
212 | ||
213 | static 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; | |
2e9ee850 AK |
221 | return 0; |
222 | } | |
223 | ||
bc0b0d6d TT |
224 | static int ext4_file_open(struct inode * inode, struct file * filp) |
225 | { | |
226 | struct super_block *sb = inode->i_sb; | |
227 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
8aefcd55 | 228 | struct ext4_inode_info *ei = EXT4_I(inode); |
bc0b0d6d TT |
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)); | |
3899167d AV |
243 | path.mnt = mnt; |
244 | path.dentry = mnt->mnt_root; | |
bc0b0d6d | 245 | cp = d_path(&path, buf, sizeof(buf)); |
bc0b0d6d | 246 | if (!IS_ERR(cp)) { |
044ce47f JK |
247 | 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 | } | |
cf803903 DW |
258 | strlcpy(sbi->s_es->s_last_mounted, cp, |
259 | sizeof(sbi->s_es->s_last_mounted)); | |
044ce47f JK |
260 | ext4_handle_dirty_super(handle, sb); |
261 | ext4_journal_stop(handle); | |
bc0b0d6d TT |
262 | } |
263 | } | |
8aefcd55 TT |
264 | /* |
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 | } | |
907f4554 | 285 | return dquot_file_open(inode, filp); |
bc0b0d6d TT |
286 | } |
287 | ||
e0d10bfa | 288 | /* |
ec7268ce ES |
289 | * 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. | |
e0d10bfa TO |
292 | */ |
293 | loff_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; | |
e0d10bfa | 302 | |
e8b96eb5 ES |
303 | return generic_file_llseek_size(file, offset, origin, |
304 | maxbytes, i_size_read(inode)); | |
e0d10bfa TO |
305 | } |
306 | ||
617ba13b | 307 | const struct file_operations ext4_file_operations = { |
e0d10bfa | 308 | .llseek = ext4_llseek, |
ac27a0ec DK |
309 | .read = do_sync_read, |
310 | .write = do_sync_write, | |
311 | .aio_read = generic_file_aio_read, | |
617ba13b | 312 | .aio_write = ext4_file_write, |
5cdd7b2d | 313 | .unlocked_ioctl = ext4_ioctl, |
ac27a0ec | 314 | #ifdef CONFIG_COMPAT |
617ba13b | 315 | .compat_ioctl = ext4_compat_ioctl, |
ac27a0ec | 316 | #endif |
2e9ee850 | 317 | .mmap = ext4_file_mmap, |
bc0b0d6d | 318 | .open = ext4_file_open, |
617ba13b MC |
319 | .release = ext4_release_file, |
320 | .fsync = ext4_sync_file, | |
ac27a0ec DK |
321 | .splice_read = generic_file_splice_read, |
322 | .splice_write = generic_file_splice_write, | |
2fe17c10 | 323 | .fallocate = ext4_fallocate, |
ac27a0ec DK |
324 | }; |
325 | ||
754661f1 | 326 | const struct inode_operations ext4_file_inode_operations = { |
617ba13b | 327 | .setattr = ext4_setattr, |
3e3398a0 | 328 | .getattr = ext4_getattr, |
03010a33 | 329 | #ifdef CONFIG_EXT4_FS_XATTR |
ac27a0ec DK |
330 | .setxattr = generic_setxattr, |
331 | .getxattr = generic_getxattr, | |
617ba13b | 332 | .listxattr = ext4_listxattr, |
ac27a0ec DK |
333 | .removexattr = generic_removexattr, |
334 | #endif | |
4e34e719 | 335 | .get_acl = ext4_get_acl, |
6873fa0d | 336 | .fiemap = ext4_fiemap, |
ac27a0ec DK |
337 | }; |
338 |