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52785112 CH |
1 | /* |
2 | * Copyright (c) 2014 Christoph Hellwig. | |
3 | */ | |
4 | #include "xfs.h" | |
5 | #include "xfs_format.h" | |
6 | #include "xfs_log_format.h" | |
7 | #include "xfs_trans_resv.h" | |
8 | #include "xfs_sb.h" | |
9 | #include "xfs_mount.h" | |
10 | #include "xfs_inode.h" | |
11 | #include "xfs_trans.h" | |
12 | #include "xfs_log.h" | |
13 | #include "xfs_bmap.h" | |
14 | #include "xfs_bmap_util.h" | |
15 | #include "xfs_error.h" | |
16 | #include "xfs_iomap.h" | |
17 | #include "xfs_shared.h" | |
18 | #include "xfs_bit.h" | |
19 | #include "xfs_pnfs.h" | |
20 | ||
781355c6 CH |
21 | /* |
22 | * Ensure that we do not have any outstanding pNFS layouts that can be used by | |
23 | * clients to directly read from or write to this inode. This must be called | |
24 | * before every operation that can remove blocks from the extent map. | |
25 | * Additionally we call it during the write operation, where aren't concerned | |
26 | * about exposing unallocated blocks but just want to provide basic | |
27 | * synchronization between a local writer and pNFS clients. mmap writes would | |
28 | * also benefit from this sort of synchronization, but due to the tricky locking | |
29 | * rules in the page fault path we don't bother. | |
30 | */ | |
31 | int | |
32 | xfs_break_layouts( | |
33 | struct inode *inode, | |
34 | uint *iolock) | |
35 | { | |
36 | struct xfs_inode *ip = XFS_I(inode); | |
37 | int error; | |
38 | ||
39 | ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)); | |
40 | ||
41 | while ((error = break_layout(inode, false) == -EWOULDBLOCK)) { | |
42 | xfs_iunlock(ip, *iolock); | |
43 | error = break_layout(inode, true); | |
44 | *iolock = XFS_IOLOCK_EXCL; | |
45 | xfs_ilock(ip, *iolock); | |
46 | } | |
47 | ||
48 | return error; | |
49 | } | |
50 | ||
52785112 CH |
51 | /* |
52 | * Get a unique ID including its location so that the client can identify | |
53 | * the exported device. | |
54 | */ | |
55 | int | |
56 | xfs_fs_get_uuid( | |
57 | struct super_block *sb, | |
58 | u8 *buf, | |
59 | u32 *len, | |
60 | u64 *offset) | |
61 | { | |
62 | struct xfs_mount *mp = XFS_M(sb); | |
63 | ||
64 | printk_once(KERN_NOTICE | |
65 | "XFS (%s): using experimental pNFS feature, use at your own risk!\n", | |
66 | mp->m_fsname); | |
67 | ||
68 | if (*len < sizeof(uuid_t)) | |
69 | return -EINVAL; | |
70 | ||
71 | memcpy(buf, &mp->m_sb.sb_uuid, sizeof(uuid_t)); | |
72 | *len = sizeof(uuid_t); | |
73 | *offset = offsetof(struct xfs_dsb, sb_uuid); | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static void | |
78 | xfs_bmbt_to_iomap( | |
79 | struct xfs_inode *ip, | |
80 | struct iomap *iomap, | |
81 | struct xfs_bmbt_irec *imap) | |
82 | { | |
83 | struct xfs_mount *mp = ip->i_mount; | |
84 | ||
85 | if (imap->br_startblock == HOLESTARTBLOCK) { | |
86 | iomap->blkno = IOMAP_NULL_BLOCK; | |
87 | iomap->type = IOMAP_HOLE; | |
88 | } else if (imap->br_startblock == DELAYSTARTBLOCK) { | |
89 | iomap->blkno = IOMAP_NULL_BLOCK; | |
90 | iomap->type = IOMAP_DELALLOC; | |
91 | } else { | |
92 | iomap->blkno = | |
93 | XFS_FSB_TO_DADDR(ip->i_mount, imap->br_startblock); | |
94 | if (imap->br_state == XFS_EXT_UNWRITTEN) | |
95 | iomap->type = IOMAP_UNWRITTEN; | |
96 | else | |
97 | iomap->type = IOMAP_MAPPED; | |
98 | } | |
99 | iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff); | |
100 | iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Get a layout for the pNFS client. | |
105 | */ | |
106 | int | |
107 | xfs_fs_map_blocks( | |
108 | struct inode *inode, | |
109 | loff_t offset, | |
110 | u64 length, | |
111 | struct iomap *iomap, | |
112 | bool write, | |
113 | u32 *device_generation) | |
114 | { | |
115 | struct xfs_inode *ip = XFS_I(inode); | |
116 | struct xfs_mount *mp = ip->i_mount; | |
117 | struct xfs_bmbt_irec imap; | |
118 | xfs_fileoff_t offset_fsb, end_fsb; | |
119 | loff_t limit; | |
120 | int bmapi_flags = XFS_BMAPI_ENTIRE; | |
121 | int nimaps = 1; | |
122 | uint lock_flags; | |
123 | int error = 0; | |
124 | ||
125 | if (XFS_FORCED_SHUTDOWN(mp)) | |
126 | return -EIO; | |
127 | ||
128 | /* | |
129 | * We can't export inodes residing on the realtime device. The realtime | |
130 | * device doesn't have a UUID to identify it, so the client has no way | |
131 | * to find it. | |
132 | */ | |
133 | if (XFS_IS_REALTIME_INODE(ip)) | |
134 | return -ENXIO; | |
135 | ||
136 | /* | |
137 | * Lock out any other I/O before we flush and invalidate the pagecache, | |
138 | * and then hand out a layout to the remote system. This is very | |
139 | * similar to direct I/O, except that the synchronization is much more | |
140 | * complicated. See the comment near xfs_break_layouts for a detailed | |
141 | * explanation. | |
142 | */ | |
143 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
144 | ||
145 | error = -EINVAL; | |
146 | limit = mp->m_super->s_maxbytes; | |
147 | if (!write) | |
148 | limit = max(limit, round_up(i_size_read(inode), | |
149 | inode->i_sb->s_blocksize)); | |
150 | if (offset > limit) | |
151 | goto out_unlock; | |
152 | if (offset > limit - length) | |
153 | length = limit - offset; | |
154 | ||
155 | error = filemap_write_and_wait(inode->i_mapping); | |
156 | if (error) | |
157 | goto out_unlock; | |
158 | error = invalidate_inode_pages2(inode->i_mapping); | |
159 | if (WARN_ON_ONCE(error)) | |
160 | return error; | |
161 | ||
162 | end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length); | |
163 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
164 | ||
165 | lock_flags = xfs_ilock_data_map_shared(ip); | |
166 | error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, | |
167 | &imap, &nimaps, bmapi_flags); | |
168 | xfs_iunlock(ip, lock_flags); | |
169 | ||
170 | if (error) | |
171 | goto out_unlock; | |
172 | ||
173 | if (write) { | |
174 | enum xfs_prealloc_flags flags = 0; | |
175 | ||
176 | ASSERT(imap.br_startblock != DELAYSTARTBLOCK); | |
177 | ||
178 | if (!nimaps || imap.br_startblock == HOLESTARTBLOCK) { | |
179 | error = xfs_iomap_write_direct(ip, offset, length, | |
180 | &imap, nimaps); | |
181 | if (error) | |
182 | goto out_unlock; | |
183 | ||
184 | /* | |
185 | * Ensure the next transaction is committed | |
186 | * synchronously so that the blocks allocated and | |
187 | * handed out to the client are guaranteed to be | |
188 | * present even after a server crash. | |
189 | */ | |
190 | flags |= XFS_PREALLOC_SET | XFS_PREALLOC_SYNC; | |
191 | } | |
192 | ||
193 | error = xfs_update_prealloc_flags(ip, flags); | |
194 | if (error) | |
195 | goto out_unlock; | |
196 | } | |
197 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
198 | ||
199 | xfs_bmbt_to_iomap(ip, iomap, &imap); | |
200 | *device_generation = mp->m_generation; | |
201 | return error; | |
202 | out_unlock: | |
203 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
204 | return error; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Ensure the size update falls into a valid allocated block. | |
209 | */ | |
210 | static int | |
211 | xfs_pnfs_validate_isize( | |
212 | struct xfs_inode *ip, | |
213 | xfs_off_t isize) | |
214 | { | |
215 | struct xfs_bmbt_irec imap; | |
216 | int nimaps = 1; | |
217 | int error = 0; | |
218 | ||
219 | xfs_ilock(ip, XFS_ILOCK_SHARED); | |
220 | error = xfs_bmapi_read(ip, XFS_B_TO_FSBT(ip->i_mount, isize - 1), 1, | |
221 | &imap, &nimaps, 0); | |
222 | xfs_iunlock(ip, XFS_ILOCK_SHARED); | |
223 | if (error) | |
224 | return error; | |
225 | ||
226 | if (imap.br_startblock == HOLESTARTBLOCK || | |
227 | imap.br_startblock == DELAYSTARTBLOCK || | |
228 | imap.br_state == XFS_EXT_UNWRITTEN) | |
229 | return -EIO; | |
230 | return 0; | |
231 | } | |
232 | ||
233 | /* | |
234 | * Make sure the blocks described by maps are stable on disk. This includes | |
235 | * converting any unwritten extents, flushing the disk cache and updating the | |
236 | * time stamps. | |
237 | * | |
238 | * Note that we rely on the caller to always send us a timestamp update so that | |
239 | * we always commit a transaction here. If that stops being true we will have | |
240 | * to manually flush the cache here similar to what the fsync code path does | |
241 | * for datasyncs on files that have no dirty metadata. | |
242 | */ | |
243 | int | |
244 | xfs_fs_commit_blocks( | |
245 | struct inode *inode, | |
246 | struct iomap *maps, | |
247 | int nr_maps, | |
248 | struct iattr *iattr) | |
249 | { | |
250 | struct xfs_inode *ip = XFS_I(inode); | |
251 | struct xfs_mount *mp = ip->i_mount; | |
252 | struct xfs_trans *tp; | |
253 | bool update_isize = false; | |
254 | int error, i; | |
255 | loff_t size; | |
256 | ||
257 | ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)); | |
258 | ||
259 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
260 | ||
261 | size = i_size_read(inode); | |
262 | if ((iattr->ia_valid & ATTR_SIZE) && iattr->ia_size > size) { | |
263 | update_isize = true; | |
264 | size = iattr->ia_size; | |
265 | } | |
266 | ||
267 | for (i = 0; i < nr_maps; i++) { | |
268 | u64 start, length, end; | |
269 | ||
270 | start = maps[i].offset; | |
271 | if (start > size) | |
272 | continue; | |
273 | ||
274 | end = start + maps[i].length; | |
275 | if (end > size) | |
276 | end = size; | |
277 | ||
278 | length = end - start; | |
279 | if (!length) | |
280 | continue; | |
281 | ||
282 | /* | |
283 | * Make sure reads through the pagecache see the new data. | |
284 | */ | |
285 | error = invalidate_inode_pages2_range(inode->i_mapping, | |
286 | start >> PAGE_CACHE_SHIFT, | |
287 | (end - 1) >> PAGE_CACHE_SHIFT); | |
288 | WARN_ON_ONCE(error); | |
289 | ||
290 | error = xfs_iomap_write_unwritten(ip, start, length); | |
291 | if (error) | |
292 | goto out_drop_iolock; | |
293 | } | |
294 | ||
295 | if (update_isize) { | |
296 | error = xfs_pnfs_validate_isize(ip, size); | |
297 | if (error) | |
298 | goto out_drop_iolock; | |
299 | } | |
300 | ||
301 | tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE); | |
302 | error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0); | |
83d5f018 ES |
303 | if (error) { |
304 | xfs_trans_cancel(tp, 0); | |
52785112 | 305 | goto out_drop_iolock; |
83d5f018 | 306 | } |
52785112 CH |
307 | |
308 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
309 | xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); | |
310 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
311 | ||
312 | xfs_setattr_time(ip, iattr); | |
313 | if (update_isize) { | |
314 | i_size_write(inode, iattr->ia_size); | |
315 | ip->i_d.di_size = iattr->ia_size; | |
316 | } | |
317 | ||
318 | xfs_trans_set_sync(tp); | |
319 | error = xfs_trans_commit(tp, 0); | |
320 | ||
321 | out_drop_iolock: | |
322 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
323 | return error; | |
324 | } |