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52785112 CH |
1 | /* |
2 | * Copyright (c) 2014 Christoph Hellwig. | |
3 | */ | |
199a31c6 | 4 | #include <linux/iomap.h> |
52785112 CH |
5 | #include "xfs.h" |
6 | #include "xfs_format.h" | |
7 | #include "xfs_log_format.h" | |
8 | #include "xfs_trans_resv.h" | |
9 | #include "xfs_sb.h" | |
10 | #include "xfs_mount.h" | |
11 | #include "xfs_inode.h" | |
12 | #include "xfs_trans.h" | |
13 | #include "xfs_log.h" | |
14 | #include "xfs_bmap.h" | |
15 | #include "xfs_bmap_util.h" | |
16 | #include "xfs_error.h" | |
17 | #include "xfs_iomap.h" | |
18 | #include "xfs_shared.h" | |
19 | #include "xfs_bit.h" | |
20 | #include "xfs_pnfs.h" | |
21 | ||
781355c6 CH |
22 | /* |
23 | * Ensure that we do not have any outstanding pNFS layouts that can be used by | |
24 | * clients to directly read from or write to this inode. This must be called | |
25 | * before every operation that can remove blocks from the extent map. | |
26 | * Additionally we call it during the write operation, where aren't concerned | |
27 | * about exposing unallocated blocks but just want to provide basic | |
28 | * synchronization between a local writer and pNFS clients. mmap writes would | |
29 | * also benefit from this sort of synchronization, but due to the tricky locking | |
30 | * rules in the page fault path we don't bother. | |
31 | */ | |
32 | int | |
33 | xfs_break_layouts( | |
34 | struct inode *inode, | |
65523218 | 35 | uint *iolock) |
781355c6 CH |
36 | { |
37 | struct xfs_inode *ip = XFS_I(inode); | |
38 | int error; | |
39 | ||
40 | ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL)); | |
41 | ||
42 | while ((error = break_layout(inode, false) == -EWOULDBLOCK)) { | |
43 | xfs_iunlock(ip, *iolock); | |
44 | error = break_layout(inode, true); | |
45 | *iolock = XFS_IOLOCK_EXCL; | |
46 | xfs_ilock(ip, *iolock); | |
47 | } | |
48 | ||
49 | return error; | |
50 | } | |
51 | ||
52785112 CH |
52 | /* |
53 | * Get a unique ID including its location so that the client can identify | |
54 | * the exported device. | |
55 | */ | |
56 | int | |
57 | xfs_fs_get_uuid( | |
58 | struct super_block *sb, | |
59 | u8 *buf, | |
60 | u32 *len, | |
61 | u64 *offset) | |
62 | { | |
63 | struct xfs_mount *mp = XFS_M(sb); | |
64 | ||
65 | printk_once(KERN_NOTICE | |
66 | "XFS (%s): using experimental pNFS feature, use at your own risk!\n", | |
67 | mp->m_fsname); | |
68 | ||
69 | if (*len < sizeof(uuid_t)) | |
70 | return -EINVAL; | |
71 | ||
72 | memcpy(buf, &mp->m_sb.sb_uuid, sizeof(uuid_t)); | |
73 | *len = sizeof(uuid_t); | |
74 | *offset = offsetof(struct xfs_dsb, sb_uuid); | |
75 | return 0; | |
76 | } | |
77 | ||
52785112 CH |
78 | /* |
79 | * Get a layout for the pNFS client. | |
80 | */ | |
81 | int | |
82 | xfs_fs_map_blocks( | |
83 | struct inode *inode, | |
84 | loff_t offset, | |
85 | u64 length, | |
86 | struct iomap *iomap, | |
87 | bool write, | |
88 | u32 *device_generation) | |
89 | { | |
90 | struct xfs_inode *ip = XFS_I(inode); | |
91 | struct xfs_mount *mp = ip->i_mount; | |
92 | struct xfs_bmbt_irec imap; | |
93 | xfs_fileoff_t offset_fsb, end_fsb; | |
94 | loff_t limit; | |
95 | int bmapi_flags = XFS_BMAPI_ENTIRE; | |
96 | int nimaps = 1; | |
97 | uint lock_flags; | |
98 | int error = 0; | |
99 | ||
100 | if (XFS_FORCED_SHUTDOWN(mp)) | |
101 | return -EIO; | |
102 | ||
103 | /* | |
104 | * We can't export inodes residing on the realtime device. The realtime | |
105 | * device doesn't have a UUID to identify it, so the client has no way | |
106 | * to find it. | |
107 | */ | |
108 | if (XFS_IS_REALTIME_INODE(ip)) | |
109 | return -ENXIO; | |
110 | ||
46eeb521 DW |
111 | /* |
112 | * The pNFS block layout spec actually supports reflink like | |
113 | * functionality, but the Linux pNFS server doesn't implement it yet. | |
114 | */ | |
115 | if (xfs_is_reflink_inode(ip)) | |
116 | return -ENXIO; | |
117 | ||
52785112 CH |
118 | /* |
119 | * Lock out any other I/O before we flush and invalidate the pagecache, | |
120 | * and then hand out a layout to the remote system. This is very | |
121 | * similar to direct I/O, except that the synchronization is much more | |
122 | * complicated. See the comment near xfs_break_layouts for a detailed | |
123 | * explanation. | |
124 | */ | |
125 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
126 | ||
127 | error = -EINVAL; | |
128 | limit = mp->m_super->s_maxbytes; | |
129 | if (!write) | |
130 | limit = max(limit, round_up(i_size_read(inode), | |
131 | inode->i_sb->s_blocksize)); | |
132 | if (offset > limit) | |
133 | goto out_unlock; | |
134 | if (offset > limit - length) | |
135 | length = limit - offset; | |
136 | ||
137 | error = filemap_write_and_wait(inode->i_mapping); | |
138 | if (error) | |
139 | goto out_unlock; | |
140 | error = invalidate_inode_pages2(inode->i_mapping); | |
141 | if (WARN_ON_ONCE(error)) | |
142 | return error; | |
143 | ||
144 | end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length); | |
145 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
146 | ||
147 | lock_flags = xfs_ilock_data_map_shared(ip); | |
148 | error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, | |
149 | &imap, &nimaps, bmapi_flags); | |
150 | xfs_iunlock(ip, lock_flags); | |
151 | ||
152 | if (error) | |
153 | goto out_unlock; | |
154 | ||
155 | if (write) { | |
156 | enum xfs_prealloc_flags flags = 0; | |
157 | ||
158 | ASSERT(imap.br_startblock != DELAYSTARTBLOCK); | |
159 | ||
160 | if (!nimaps || imap.br_startblock == HOLESTARTBLOCK) { | |
009c6e87 BF |
161 | /* |
162 | * xfs_iomap_write_direct() expects to take ownership of | |
163 | * the shared ilock. | |
164 | */ | |
165 | xfs_ilock(ip, XFS_ILOCK_SHARED); | |
52785112 CH |
166 | error = xfs_iomap_write_direct(ip, offset, length, |
167 | &imap, nimaps); | |
168 | if (error) | |
169 | goto out_unlock; | |
170 | ||
171 | /* | |
172 | * Ensure the next transaction is committed | |
173 | * synchronously so that the blocks allocated and | |
174 | * handed out to the client are guaranteed to be | |
175 | * present even after a server crash. | |
176 | */ | |
177 | flags |= XFS_PREALLOC_SET | XFS_PREALLOC_SYNC; | |
178 | } | |
179 | ||
180 | error = xfs_update_prealloc_flags(ip, flags); | |
181 | if (error) | |
182 | goto out_unlock; | |
183 | } | |
184 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
185 | ||
186 | xfs_bmbt_to_iomap(ip, iomap, &imap); | |
187 | *device_generation = mp->m_generation; | |
188 | return error; | |
189 | out_unlock: | |
190 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
191 | return error; | |
192 | } | |
193 | ||
194 | /* | |
195 | * Ensure the size update falls into a valid allocated block. | |
196 | */ | |
197 | static int | |
198 | xfs_pnfs_validate_isize( | |
199 | struct xfs_inode *ip, | |
200 | xfs_off_t isize) | |
201 | { | |
202 | struct xfs_bmbt_irec imap; | |
203 | int nimaps = 1; | |
204 | int error = 0; | |
205 | ||
206 | xfs_ilock(ip, XFS_ILOCK_SHARED); | |
207 | error = xfs_bmapi_read(ip, XFS_B_TO_FSBT(ip->i_mount, isize - 1), 1, | |
208 | &imap, &nimaps, 0); | |
209 | xfs_iunlock(ip, XFS_ILOCK_SHARED); | |
210 | if (error) | |
211 | return error; | |
212 | ||
213 | if (imap.br_startblock == HOLESTARTBLOCK || | |
214 | imap.br_startblock == DELAYSTARTBLOCK || | |
215 | imap.br_state == XFS_EXT_UNWRITTEN) | |
216 | return -EIO; | |
217 | return 0; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Make sure the blocks described by maps are stable on disk. This includes | |
222 | * converting any unwritten extents, flushing the disk cache and updating the | |
223 | * time stamps. | |
224 | * | |
225 | * Note that we rely on the caller to always send us a timestamp update so that | |
226 | * we always commit a transaction here. If that stops being true we will have | |
227 | * to manually flush the cache here similar to what the fsync code path does | |
228 | * for datasyncs on files that have no dirty metadata. | |
229 | */ | |
230 | int | |
231 | xfs_fs_commit_blocks( | |
232 | struct inode *inode, | |
233 | struct iomap *maps, | |
234 | int nr_maps, | |
235 | struct iattr *iattr) | |
236 | { | |
237 | struct xfs_inode *ip = XFS_I(inode); | |
238 | struct xfs_mount *mp = ip->i_mount; | |
239 | struct xfs_trans *tp; | |
240 | bool update_isize = false; | |
241 | int error, i; | |
242 | loff_t size; | |
243 | ||
244 | ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)); | |
245 | ||
246 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
247 | ||
248 | size = i_size_read(inode); | |
249 | if ((iattr->ia_valid & ATTR_SIZE) && iattr->ia_size > size) { | |
250 | update_isize = true; | |
251 | size = iattr->ia_size; | |
252 | } | |
253 | ||
254 | for (i = 0; i < nr_maps; i++) { | |
255 | u64 start, length, end; | |
256 | ||
257 | start = maps[i].offset; | |
258 | if (start > size) | |
259 | continue; | |
260 | ||
261 | end = start + maps[i].length; | |
262 | if (end > size) | |
263 | end = size; | |
264 | ||
265 | length = end - start; | |
266 | if (!length) | |
267 | continue; | |
268 | ||
269 | /* | |
270 | * Make sure reads through the pagecache see the new data. | |
271 | */ | |
272 | error = invalidate_inode_pages2_range(inode->i_mapping, | |
09cbfeaf KS |
273 | start >> PAGE_SHIFT, |
274 | (end - 1) >> PAGE_SHIFT); | |
52785112 CH |
275 | WARN_ON_ONCE(error); |
276 | ||
277 | error = xfs_iomap_write_unwritten(ip, start, length); | |
278 | if (error) | |
279 | goto out_drop_iolock; | |
280 | } | |
281 | ||
282 | if (update_isize) { | |
283 | error = xfs_pnfs_validate_isize(ip, size); | |
284 | if (error) | |
285 | goto out_drop_iolock; | |
286 | } | |
287 | ||
253f4911 CH |
288 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); |
289 | if (error) | |
52785112 CH |
290 | goto out_drop_iolock; |
291 | ||
292 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
293 | xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); | |
294 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
295 | ||
296 | xfs_setattr_time(ip, iattr); | |
297 | if (update_isize) { | |
298 | i_size_write(inode, iattr->ia_size); | |
299 | ip->i_d.di_size = iattr->ia_size; | |
300 | } | |
301 | ||
302 | xfs_trans_set_sync(tp); | |
70393313 | 303 | error = xfs_trans_commit(tp); |
52785112 CH |
304 | |
305 | out_drop_iolock: | |
306 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
307 | return error; | |
308 | } |