xref: /openbmc/linux/fs/nfsd/blocklayout.c (revision b96fc2f3)
1 /*
2  * Copyright (c) 2014 Christoph Hellwig.
3  */
4 #include <linux/exportfs.h>
5 #include <linux/genhd.h>
6 #include <linux/slab.h>
7 
8 #include <linux/nfsd/debug.h>
9 
10 #include "blocklayoutxdr.h"
11 #include "pnfs.h"
12 
13 #define NFSDDBG_FACILITY	NFSDDBG_PNFS
14 
15 
16 static int
17 nfsd4_block_get_device_info_simple(struct super_block *sb,
18 		struct nfsd4_getdeviceinfo *gdp)
19 {
20 	struct pnfs_block_deviceaddr *dev;
21 	struct pnfs_block_volume *b;
22 
23 	dev = kzalloc(sizeof(struct pnfs_block_deviceaddr) +
24 		      sizeof(struct pnfs_block_volume), GFP_KERNEL);
25 	if (!dev)
26 		return -ENOMEM;
27 	gdp->gd_device = dev;
28 
29 	dev->nr_volumes = 1;
30 	b = &dev->volumes[0];
31 
32 	b->type = PNFS_BLOCK_VOLUME_SIMPLE;
33 	b->simple.sig_len = PNFS_BLOCK_UUID_LEN;
34 	return sb->s_export_op->get_uuid(sb, b->simple.sig, &b->simple.sig_len,
35 			&b->simple.offset);
36 }
37 
38 static __be32
39 nfsd4_block_proc_getdeviceinfo(struct super_block *sb,
40 		struct nfsd4_getdeviceinfo *gdp)
41 {
42 	if (sb->s_bdev != sb->s_bdev->bd_contains)
43 		return nfserr_inval;
44 	return nfserrno(nfsd4_block_get_device_info_simple(sb, gdp));
45 }
46 
47 static __be32
48 nfsd4_block_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
49 		struct nfsd4_layoutget *args)
50 {
51 	struct nfsd4_layout_seg *seg = &args->lg_seg;
52 	struct super_block *sb = inode->i_sb;
53 	u32 block_size = (1 << inode->i_blkbits);
54 	struct pnfs_block_extent *bex;
55 	struct iomap iomap;
56 	u32 device_generation = 0;
57 	int error;
58 
59 	/*
60 	 * We do not attempt to support I/O smaller than the fs block size,
61 	 * or not aligned to it.
62 	 */
63 	if (args->lg_minlength < block_size) {
64 		dprintk("pnfsd: I/O too small\n");
65 		goto out_layoutunavailable;
66 	}
67 	if (seg->offset & (block_size - 1)) {
68 		dprintk("pnfsd: I/O misaligned\n");
69 		goto out_layoutunavailable;
70 	}
71 
72 	/*
73 	 * Some clients barf on non-zero block numbers for NONE or INVALID
74 	 * layouts, so make sure to zero the whole structure.
75 	 */
76 	error = -ENOMEM;
77 	bex = kzalloc(sizeof(*bex), GFP_KERNEL);
78 	if (!bex)
79 		goto out_error;
80 	args->lg_content = bex;
81 
82 	error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
83 					    &iomap, seg->iomode != IOMODE_READ,
84 					    &device_generation);
85 	if (error) {
86 		if (error == -ENXIO)
87 			goto out_layoutunavailable;
88 		goto out_error;
89 	}
90 
91 	if (iomap.length < args->lg_minlength) {
92 		dprintk("pnfsd: extent smaller than minlength\n");
93 		goto out_layoutunavailable;
94 	}
95 
96 	switch (iomap.type) {
97 	case IOMAP_MAPPED:
98 		if (seg->iomode == IOMODE_READ)
99 			bex->es = PNFS_BLOCK_READ_DATA;
100 		else
101 			bex->es = PNFS_BLOCK_READWRITE_DATA;
102 		bex->soff = (iomap.blkno << 9);
103 		break;
104 	case IOMAP_UNWRITTEN:
105 		if (seg->iomode & IOMODE_RW) {
106 			/*
107 			 * Crack monkey special case from section 2.3.1.
108 			 */
109 			if (args->lg_minlength == 0) {
110 				dprintk("pnfsd: no soup for you!\n");
111 				goto out_layoutunavailable;
112 			}
113 
114 			bex->es = PNFS_BLOCK_INVALID_DATA;
115 			bex->soff = (iomap.blkno << 9);
116 			break;
117 		}
118 		/*FALLTHRU*/
119 	case IOMAP_HOLE:
120 		if (seg->iomode == IOMODE_READ) {
121 			bex->es = PNFS_BLOCK_NONE_DATA;
122 			break;
123 		}
124 		/*FALLTHRU*/
125 	case IOMAP_DELALLOC:
126 	default:
127 		WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
128 		goto out_layoutunavailable;
129 	}
130 
131 	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
132 	if (error)
133 		goto out_error;
134 	bex->foff = iomap.offset;
135 	bex->len = iomap.length;
136 
137 	seg->offset = iomap.offset;
138 	seg->length = iomap.length;
139 
140 	dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
141 	return 0;
142 
143 out_error:
144 	seg->length = 0;
145 	return nfserrno(error);
146 out_layoutunavailable:
147 	seg->length = 0;
148 	return nfserr_layoutunavailable;
149 }
150 
151 static __be32
152 nfsd4_block_proc_layoutcommit(struct inode *inode,
153 		struct nfsd4_layoutcommit *lcp)
154 {
155 	loff_t new_size = lcp->lc_last_wr + 1;
156 	struct iattr iattr = { .ia_valid = 0 };
157 	struct iomap *iomaps;
158 	int nr_iomaps;
159 	int error;
160 
161 	nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
162 			lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
163 	if (nr_iomaps < 0)
164 		return nfserrno(nr_iomaps);
165 
166 	if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
167 	    timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
168 		lcp->lc_mtime = current_fs_time(inode->i_sb);
169 	iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
170 	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
171 
172 	if (new_size > i_size_read(inode)) {
173 		iattr.ia_valid |= ATTR_SIZE;
174 		iattr.ia_size = new_size;
175 	}
176 
177 	error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
178 			nr_iomaps, &iattr);
179 	kfree(iomaps);
180 	return nfserrno(error);
181 }
182 
183 const struct nfsd4_layout_ops bl_layout_ops = {
184 	/*
185 	 * Pretend that we send notification to the client.  This is a blatant
186 	 * lie to force recent Linux clients to cache our device IDs.
187 	 * We rarely ever change the device ID, so the harm of leaking deviceids
188 	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
189 	 * in this regard, but I filed errata 4119 for this a while ago, and
190 	 * hopefully the Linux client will eventually start caching deviceids
191 	 * without this again.
192 	 */
193 	.notify_types		=
194 			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
195 	.proc_getdeviceinfo	= nfsd4_block_proc_getdeviceinfo,
196 	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
197 	.proc_layoutget		= nfsd4_block_proc_layoutget,
198 	.encode_layoutget	= nfsd4_block_encode_layoutget,
199 	.proc_layoutcommit	= nfsd4_block_proc_layoutcommit,
200 };
201