2 * Copyright (c) 2014 Christoph Hellwig.
5 #include "xfs_format.h"
6 #include "xfs_log_format.h"
7 #include "xfs_trans_resv.h"
10 #include "xfs_inode.h"
11 #include "xfs_trans.h"
14 #include "xfs_bmap_util.h"
15 #include "xfs_error.h"
16 #include "xfs_iomap.h"
17 #include "xfs_shared.h"
22 * Get a unique ID including its location so that the client can identify
23 * the exported device.
27 struct super_block *sb,
32 struct xfs_mount *mp = XFS_M(sb);
34 printk_once(KERN_NOTICE
35 "XFS (%s): using experimental pNFS feature, use at your own risk!\n",
38 if (*len < sizeof(uuid_t))
41 memcpy(buf, &mp->m_sb.sb_uuid, sizeof(uuid_t));
42 *len = sizeof(uuid_t);
43 *offset = offsetof(struct xfs_dsb, sb_uuid);
51 struct xfs_bmbt_irec *imap)
53 struct xfs_mount *mp = ip->i_mount;
55 if (imap->br_startblock == HOLESTARTBLOCK) {
56 iomap->blkno = IOMAP_NULL_BLOCK;
57 iomap->type = IOMAP_HOLE;
58 } else if (imap->br_startblock == DELAYSTARTBLOCK) {
59 iomap->blkno = IOMAP_NULL_BLOCK;
60 iomap->type = IOMAP_DELALLOC;
63 XFS_FSB_TO_DADDR(ip->i_mount, imap->br_startblock);
64 if (imap->br_state == XFS_EXT_UNWRITTEN)
65 iomap->type = IOMAP_UNWRITTEN;
67 iomap->type = IOMAP_MAPPED;
69 iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff);
70 iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
74 * Get a layout for the pNFS client.
83 u32 *device_generation)
85 struct xfs_inode *ip = XFS_I(inode);
86 struct xfs_mount *mp = ip->i_mount;
87 struct xfs_bmbt_irec imap;
88 xfs_fileoff_t offset_fsb, end_fsb;
90 int bmapi_flags = XFS_BMAPI_ENTIRE;
95 if (XFS_FORCED_SHUTDOWN(mp))
99 * We can't export inodes residing on the realtime device. The realtime
100 * device doesn't have a UUID to identify it, so the client has no way
103 if (XFS_IS_REALTIME_INODE(ip))
107 * Lock out any other I/O before we flush and invalidate the pagecache,
108 * and then hand out a layout to the remote system. This is very
109 * similar to direct I/O, except that the synchronization is much more
110 * complicated. See the comment near xfs_break_layouts for a detailed
113 xfs_ilock(ip, XFS_IOLOCK_EXCL);
116 limit = mp->m_super->s_maxbytes;
118 limit = max(limit, round_up(i_size_read(inode),
119 inode->i_sb->s_blocksize));
122 if (offset > limit - length)
123 length = limit - offset;
125 error = filemap_write_and_wait(inode->i_mapping);
128 error = invalidate_inode_pages2(inode->i_mapping);
129 if (WARN_ON_ONCE(error))
132 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + length);
133 offset_fsb = XFS_B_TO_FSBT(mp, offset);
135 lock_flags = xfs_ilock_data_map_shared(ip);
136 error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb,
137 &imap, &nimaps, bmapi_flags);
138 xfs_iunlock(ip, lock_flags);
144 enum xfs_prealloc_flags flags = 0;
146 ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
148 if (!nimaps || imap.br_startblock == HOLESTARTBLOCK) {
149 error = xfs_iomap_write_direct(ip, offset, length,
155 * Ensure the next transaction is committed
156 * synchronously so that the blocks allocated and
157 * handed out to the client are guaranteed to be
158 * present even after a server crash.
160 flags |= XFS_PREALLOC_SET | XFS_PREALLOC_SYNC;
163 error = xfs_update_prealloc_flags(ip, flags);
167 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
169 xfs_bmbt_to_iomap(ip, iomap, &imap);
170 *device_generation = mp->m_generation;
173 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
178 * Ensure the size update falls into a valid allocated block.
181 xfs_pnfs_validate_isize(
182 struct xfs_inode *ip,
185 struct xfs_bmbt_irec imap;
189 xfs_ilock(ip, XFS_ILOCK_SHARED);
190 error = xfs_bmapi_read(ip, XFS_B_TO_FSBT(ip->i_mount, isize - 1), 1,
192 xfs_iunlock(ip, XFS_ILOCK_SHARED);
196 if (imap.br_startblock == HOLESTARTBLOCK ||
197 imap.br_startblock == DELAYSTARTBLOCK ||
198 imap.br_state == XFS_EXT_UNWRITTEN)
204 * Make sure the blocks described by maps are stable on disk. This includes
205 * converting any unwritten extents, flushing the disk cache and updating the
208 * Note that we rely on the caller to always send us a timestamp update so that
209 * we always commit a transaction here. If that stops being true we will have
210 * to manually flush the cache here similar to what the fsync code path does
211 * for datasyncs on files that have no dirty metadata.
214 xfs_fs_commit_blocks(
220 struct xfs_inode *ip = XFS_I(inode);
221 struct xfs_mount *mp = ip->i_mount;
222 struct xfs_trans *tp;
223 bool update_isize = false;
227 ASSERT(iattr->ia_valid & (ATTR_ATIME|ATTR_CTIME|ATTR_MTIME));
229 xfs_ilock(ip, XFS_IOLOCK_EXCL);
231 size = i_size_read(inode);
232 if ((iattr->ia_valid & ATTR_SIZE) && iattr->ia_size > size) {
234 size = iattr->ia_size;
237 for (i = 0; i < nr_maps; i++) {
238 u64 start, length, end;
240 start = maps[i].offset;
244 end = start + maps[i].length;
248 length = end - start;
253 * Make sure reads through the pagecache see the new data.
255 error = invalidate_inode_pages2_range(inode->i_mapping,
256 start >> PAGE_CACHE_SHIFT,
257 (end - 1) >> PAGE_CACHE_SHIFT);
260 error = xfs_iomap_write_unwritten(ip, start, length);
262 goto out_drop_iolock;
266 error = xfs_pnfs_validate_isize(ip, size);
268 goto out_drop_iolock;
271 tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
272 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_ichange, 0, 0);
274 goto out_drop_iolock;
276 xfs_ilock(ip, XFS_ILOCK_EXCL);
277 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
278 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
280 xfs_setattr_time(ip, iattr);
282 i_size_write(inode, iattr->ia_size);
283 ip->i_d.di_size = iattr->ia_size;
286 xfs_trans_set_sync(tp);
287 error = xfs_trans_commit(tp, 0);
290 xfs_iunlock(ip, XFS_IOLOCK_EXCL);