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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
52785112 CH |
2 | /* |
3 | * Copyright (c) 2014 Christoph Hellwig. | |
4 | */ | |
5 | #include "xfs.h" | |
5467b34b | 6 | #include "xfs_shared.h" |
52785112 CH |
7 | #include "xfs_format.h" |
8 | #include "xfs_log_format.h" | |
9 | #include "xfs_trans_resv.h" | |
52785112 CH |
10 | #include "xfs_mount.h" |
11 | #include "xfs_inode.h" | |
12 | #include "xfs_trans.h" | |
52785112 | 13 | #include "xfs_bmap.h" |
52785112 | 14 | #include "xfs_iomap.h" |
1aa63006 | 15 | #include "xfs_pnfs.h" |
52785112 | 16 | |
781355c6 CH |
17 | /* |
18 | * Ensure that we do not have any outstanding pNFS layouts that can be used by | |
19 | * clients to directly read from or write to this inode. This must be called | |
20 | * before every operation that can remove blocks from the extent map. | |
21 | * Additionally we call it during the write operation, where aren't concerned | |
22 | * about exposing unallocated blocks but just want to provide basic | |
23 | * synchronization between a local writer and pNFS clients. mmap writes would | |
24 | * also benefit from this sort of synchronization, but due to the tricky locking | |
25 | * rules in the page fault path we don't bother. | |
26 | */ | |
27 | int | |
69eb5fa1 | 28 | xfs_break_leased_layouts( |
781355c6 | 29 | struct inode *inode, |
69eb5fa1 DW |
30 | uint *iolock, |
31 | bool *did_unlock) | |
781355c6 CH |
32 | { |
33 | struct xfs_inode *ip = XFS_I(inode); | |
34 | int error; | |
35 | ||
b6827160 | 36 | while ((error = break_layout(inode, false)) == -EWOULDBLOCK) { |
781355c6 | 37 | xfs_iunlock(ip, *iolock); |
69eb5fa1 | 38 | *did_unlock = true; |
781355c6 | 39 | error = break_layout(inode, true); |
c63a8eae DW |
40 | *iolock &= ~XFS_IOLOCK_SHARED; |
41 | *iolock |= XFS_IOLOCK_EXCL; | |
781355c6 CH |
42 | xfs_ilock(ip, *iolock); |
43 | } | |
44 | ||
45 | return error; | |
46 | } | |
47 | ||
52785112 CH |
48 | /* |
49 | * Get a unique ID including its location so that the client can identify | |
50 | * the exported device. | |
51 | */ | |
52 | int | |
53 | xfs_fs_get_uuid( | |
54 | struct super_block *sb, | |
55 | u8 *buf, | |
56 | u32 *len, | |
57 | u64 *offset) | |
58 | { | |
59 | struct xfs_mount *mp = XFS_M(sb); | |
60 | ||
61 | printk_once(KERN_NOTICE | |
62 | "XFS (%s): using experimental pNFS feature, use at your own risk!\n", | |
63 | mp->m_fsname); | |
64 | ||
65 | if (*len < sizeof(uuid_t)) | |
66 | return -EINVAL; | |
67 | ||
68 | memcpy(buf, &mp->m_sb.sb_uuid, sizeof(uuid_t)); | |
69 | *len = sizeof(uuid_t); | |
70 | *offset = offsetof(struct xfs_dsb, sb_uuid); | |
71 | return 0; | |
72 | } | |
73 | ||
52785112 CH |
74 | /* |
75 | * Get a layout for the pNFS client. | |
76 | */ | |
77 | int | |
78 | xfs_fs_map_blocks( | |
79 | struct inode *inode, | |
80 | loff_t offset, | |
81 | u64 length, | |
82 | struct iomap *iomap, | |
83 | bool write, | |
84 | u32 *device_generation) | |
85 | { | |
86 | struct xfs_inode *ip = XFS_I(inode); | |
87 | struct xfs_mount *mp = ip->i_mount; | |
88 | struct xfs_bmbt_irec imap; | |
89 | xfs_fileoff_t offset_fsb, end_fsb; | |
90 | loff_t limit; | |
91 | int bmapi_flags = XFS_BMAPI_ENTIRE; | |
92 | int nimaps = 1; | |
93 | uint lock_flags; | |
94 | int error = 0; | |
95 | ||
96 | if (XFS_FORCED_SHUTDOWN(mp)) | |
97 | return -EIO; | |
98 | ||
99 | /* | |
100 | * We can't export inodes residing on the realtime device. The realtime | |
101 | * device doesn't have a UUID to identify it, so the client has no way | |
102 | * to find it. | |
103 | */ | |
104 | if (XFS_IS_REALTIME_INODE(ip)) | |
105 | return -ENXIO; | |
106 | ||
46eeb521 DW |
107 | /* |
108 | * The pNFS block layout spec actually supports reflink like | |
109 | * functionality, but the Linux pNFS server doesn't implement it yet. | |
110 | */ | |
111 | if (xfs_is_reflink_inode(ip)) | |
112 | return -ENXIO; | |
113 | ||
52785112 CH |
114 | /* |
115 | * Lock out any other I/O before we flush and invalidate the pagecache, | |
116 | * and then hand out a layout to the remote system. This is very | |
117 | * similar to direct I/O, except that the synchronization is much more | |
69eb5fa1 DW |
118 | * complicated. See the comment near xfs_break_leased_layouts |
119 | * for a detailed explanation. | |
52785112 CH |
120 | */ |
121 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
122 | ||
123 | error = -EINVAL; | |
124 | limit = mp->m_super->s_maxbytes; | |
125 | if (!write) | |
126 | limit = max(limit, round_up(i_size_read(inode), | |
127 | inode->i_sb->s_blocksize)); | |
128 | if (offset > limit) | |
129 | goto out_unlock; | |
130 | if (offset > limit - length) | |
131 | length = limit - offset; | |
132 | ||
133 | error = filemap_write_and_wait(inode->i_mapping); | |
134 | if (error) | |
135 | goto out_unlock; | |
136 | error = invalidate_inode_pages2(inode->i_mapping); | |
137 | if (WARN_ON_ONCE(error)) | |
138 | return error; | |
139 | ||
140 | end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length); | |
141 | offset_fsb = XFS_B_TO_FSBT(mp, offset); | |
142 | ||
143 | lock_flags = xfs_ilock_data_map_shared(ip); | |
144 | error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, | |
145 | &imap, &nimaps, bmapi_flags); | |
52785112 | 146 | |
88cdb714 CH |
147 | ASSERT(!nimaps || imap.br_startblock != DELAYSTARTBLOCK); |
148 | ||
e696663a CH |
149 | if (!error && write && |
150 | (!nimaps || imap.br_startblock == HOLESTARTBLOCK)) { | |
151 | if (offset + length > XFS_ISIZE(ip)) | |
152 | end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb); | |
153 | else if (nimaps && imap.br_startblock == HOLESTARTBLOCK) | |
154 | end_fsb = min(end_fsb, imap.br_startoff + | |
155 | imap.br_blockcount); | |
156 | xfs_iunlock(ip, lock_flags); | |
157 | ||
158 | error = xfs_iomap_write_direct(ip, offset_fsb, | |
159 | end_fsb - offset_fsb, &imap); | |
307cdb54 CH |
160 | if (error) |
161 | goto out_unlock; | |
162 | ||
163 | /* | |
164 | * Ensure the next transaction is committed synchronously so | |
165 | * that the blocks allocated and handed out to the client are | |
166 | * guaranteed to be present even after a server crash. | |
167 | */ | |
168 | error = xfs_update_prealloc_flags(ip, | |
169 | XFS_PREALLOC_SET | XFS_PREALLOC_SYNC); | |
52785112 CH |
170 | if (error) |
171 | goto out_unlock; | |
e696663a CH |
172 | } else { |
173 | xfs_iunlock(ip, lock_flags); | |
52785112 CH |
174 | } |
175 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
176 | ||
2492a606 | 177 | error = xfs_bmbt_to_iomap(ip, iomap, &imap, 0); |
52785112 CH |
178 | *device_generation = mp->m_generation; |
179 | return error; | |
180 | out_unlock: | |
181 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
182 | return error; | |
183 | } | |
184 | ||
185 | /* | |
186 | * Ensure the size update falls into a valid allocated block. | |
187 | */ | |
188 | static int | |
189 | xfs_pnfs_validate_isize( | |
190 | struct xfs_inode *ip, | |
191 | xfs_off_t isize) | |
192 | { | |
193 | struct xfs_bmbt_irec imap; | |
194 | int nimaps = 1; | |
195 | int error = 0; | |
196 | ||
197 | xfs_ilock(ip, XFS_ILOCK_SHARED); | |
198 | error = xfs_bmapi_read(ip, XFS_B_TO_FSBT(ip->i_mount, isize - 1), 1, | |
199 | &imap, &nimaps, 0); | |
200 | xfs_iunlock(ip, XFS_ILOCK_SHARED); | |
201 | if (error) | |
202 | return error; | |
203 | ||
204 | if (imap.br_startblock == HOLESTARTBLOCK || | |
205 | imap.br_startblock == DELAYSTARTBLOCK || | |
206 | imap.br_state == XFS_EXT_UNWRITTEN) | |
207 | return -EIO; | |
208 | return 0; | |
209 | } | |
210 | ||
211 | /* | |
212 | * Make sure the blocks described by maps are stable on disk. This includes | |
213 | * converting any unwritten extents, flushing the disk cache and updating the | |
214 | * time stamps. | |
215 | * | |
216 | * Note that we rely on the caller to always send us a timestamp update so that | |
217 | * we always commit a transaction here. If that stops being true we will have | |
218 | * to manually flush the cache here similar to what the fsync code path does | |
219 | * for datasyncs on files that have no dirty metadata. | |
220 | */ | |
221 | int | |
222 | xfs_fs_commit_blocks( | |
223 | struct inode *inode, | |
224 | struct iomap *maps, | |
225 | int nr_maps, | |
226 | struct iattr *iattr) | |
227 | { | |
228 | struct xfs_inode *ip = XFS_I(inode); | |
229 | struct xfs_mount *mp = ip->i_mount; | |
230 | struct xfs_trans *tp; | |
231 | bool update_isize = false; | |
232 | int error, i; | |
233 | loff_t size; | |
234 | ||
235 | ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME)); | |
236 | ||
237 | xfs_ilock(ip, XFS_IOLOCK_EXCL); | |
238 | ||
239 | size = i_size_read(inode); | |
240 | if ((iattr->ia_valid & ATTR_SIZE) && iattr->ia_size > size) { | |
241 | update_isize = true; | |
242 | size = iattr->ia_size; | |
243 | } | |
244 | ||
245 | for (i = 0; i < nr_maps; i++) { | |
246 | u64 start, length, end; | |
247 | ||
248 | start = maps[i].offset; | |
249 | if (start > size) | |
250 | continue; | |
251 | ||
252 | end = start + maps[i].length; | |
253 | if (end > size) | |
254 | end = size; | |
255 | ||
256 | length = end - start; | |
257 | if (!length) | |
258 | continue; | |
259 | ||
260 | /* | |
261 | * Make sure reads through the pagecache see the new data. | |
262 | */ | |
263 | error = invalidate_inode_pages2_range(inode->i_mapping, | |
09cbfeaf KS |
264 | start >> PAGE_SHIFT, |
265 | (end - 1) >> PAGE_SHIFT); | |
52785112 CH |
266 | WARN_ON_ONCE(error); |
267 | ||
ee70daab | 268 | error = xfs_iomap_write_unwritten(ip, start, length, false); |
52785112 CH |
269 | if (error) |
270 | goto out_drop_iolock; | |
271 | } | |
272 | ||
273 | if (update_isize) { | |
274 | error = xfs_pnfs_validate_isize(ip, size); | |
275 | if (error) | |
276 | goto out_drop_iolock; | |
277 | } | |
278 | ||
253f4911 CH |
279 | error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); |
280 | if (error) | |
52785112 CH |
281 | goto out_drop_iolock; |
282 | ||
283 | xfs_ilock(ip, XFS_ILOCK_EXCL); | |
284 | xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); | |
285 | xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); | |
286 | ||
287 | xfs_setattr_time(ip, iattr); | |
288 | if (update_isize) { | |
289 | i_size_write(inode, iattr->ia_size); | |
290 | ip->i_d.di_size = iattr->ia_size; | |
291 | } | |
292 | ||
293 | xfs_trans_set_sync(tp); | |
70393313 | 294 | error = xfs_trans_commit(tp); |
52785112 CH |
295 | |
296 | out_drop_iolock: | |
297 | xfs_iunlock(ip, XFS_IOLOCK_EXCL); | |
298 | return error; | |
299 | } |