cfg80211: Fix array-bounds warning in fragment copy
[linux/fpc-iii.git] / fs / xfs / xfs_pnfs.c
blob2f2dc3c09ad008a75fa0ffba6fd5d7aed392c162
1 /*
2 * Copyright (c) 2014 Christoph Hellwig.
3 */
4 #include <linux/iomap.h>
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"
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.
32 int
33 xfs_break_layouts(
34 struct inode *inode,
35 uint *iolock)
37 struct xfs_inode *ip = XFS_I(inode);
38 int error;
40 ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
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);
49 return error;
53 * Get a unique ID including its location so that the client can identify
54 * the exported device.
56 int
57 xfs_fs_get_uuid(
58 struct super_block *sb,
59 u8 *buf,
60 u32 *len,
61 u64 *offset)
63 struct xfs_mount *mp = XFS_M(sb);
65 printk_once(KERN_NOTICE
66 "XFS (%s): using experimental pNFS feature, use at your own risk!\n",
67 mp->m_fsname);
69 if (*len < sizeof(uuid_t))
70 return -EINVAL;
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;
79 * Get a layout for the pNFS client.
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)
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;
100 if (XFS_FORCED_SHUTDOWN(mp))
101 return -EIO;
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.
108 if (XFS_IS_REALTIME_INODE(ip))
109 return -ENXIO;
112 * The pNFS block layout spec actually supports reflink like
113 * functionality, but the Linux pNFS server doesn't implement it yet.
115 if (xfs_is_reflink_inode(ip))
116 return -ENXIO;
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.
125 xfs_ilock(ip, XFS_IOLOCK_EXCL);
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;
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;
144 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length);
145 offset_fsb = XFS_B_TO_FSBT(mp, offset);
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);
152 if (error)
153 goto out_unlock;
155 if (write) {
156 enum xfs_prealloc_flags flags = 0;
158 ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
160 if (!nimaps || imap.br_startblock == HOLESTARTBLOCK) {
162 * xfs_iomap_write_direct() expects to take ownership of
163 * the shared ilock.
165 xfs_ilock(ip, XFS_ILOCK_SHARED);
166 error = xfs_iomap_write_direct(ip, offset, length,
167 &imap, nimaps);
168 if (error)
169 goto out_unlock;
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.
177 flags |= XFS_PREALLOC_SET | XFS_PREALLOC_SYNC;
180 error = xfs_update_prealloc_flags(ip, flags);
181 if (error)
182 goto out_unlock;
184 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
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;
195 * Ensure the size update falls into a valid allocated block.
197 static int
198 xfs_pnfs_validate_isize(
199 struct xfs_inode *ip,
200 xfs_off_t isize)
202 struct xfs_bmbt_irec imap;
203 int nimaps = 1;
204 int error = 0;
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;
213 if (imap.br_startblock == HOLESTARTBLOCK ||
214 imap.br_startblock == DELAYSTARTBLOCK ||
215 imap.br_state == XFS_EXT_UNWRITTEN)
216 return -EIO;
217 return 0;
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.
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.
231 xfs_fs_commit_blocks(
232 struct inode *inode,
233 struct iomap *maps,
234 int nr_maps,
235 struct iattr *iattr)
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;
244 ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME));
246 xfs_ilock(ip, XFS_IOLOCK_EXCL);
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;
254 for (i = 0; i < nr_maps; i++) {
255 u64 start, length, end;
257 start = maps[i].offset;
258 if (start > size)
259 continue;
261 end = start + maps[i].length;
262 if (end > size)
263 end = size;
265 length = end - start;
266 if (!length)
267 continue;
270 * Make sure reads through the pagecache see the new data.
272 error = invalidate_inode_pages2_range(inode->i_mapping,
273 start >> PAGE_SHIFT,
274 (end - 1) >> PAGE_SHIFT);
275 WARN_ON_ONCE(error);
277 error = xfs_iomap_write_unwritten(ip, start, length);
278 if (error)
279 goto out_drop_iolock;
282 if (update_isize) {
283 error = xfs_pnfs_validate_isize(ip, size);
284 if (error)
285 goto out_drop_iolock;
288 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp);
289 if (error)
290 goto out_drop_iolock;
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);
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;
302 xfs_trans_set_sync(tp);
303 error = xfs_trans_commit(tp);
305 out_drop_iolock:
306 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
307 return error;