xref: /linux/fs/nfsd/blocklayout.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 	if (seg->offset & (block_size - 1)) {
60 		dprintk("pnfsd: I/O misaligned\n");
61 		goto out_layoutunavailable;
62 	}
63 
64 	/*
65 	 * Some clients barf on non-zero block numbers for NONE or INVALID
66 	 * layouts, so make sure to zero the whole structure.
67 	 */
68 	error = -ENOMEM;
69 	bex = kzalloc(sizeof(*bex), GFP_KERNEL);
70 	if (!bex)
71 		goto out_error;
72 	args->lg_content = bex;
73 
74 	error = sb->s_export_op->map_blocks(inode, seg->offset, seg->length,
75 					    &iomap, seg->iomode != IOMODE_READ,
76 					    &device_generation);
77 	if (error) {
78 		if (error == -ENXIO)
79 			goto out_layoutunavailable;
80 		goto out_error;
81 	}
82 
83 	if (iomap.length < args->lg_minlength) {
84 		dprintk("pnfsd: extent smaller than minlength\n");
85 		goto out_layoutunavailable;
86 	}
87 
88 	switch (iomap.type) {
89 	case IOMAP_MAPPED:
90 		if (seg->iomode == IOMODE_READ)
91 			bex->es = PNFS_BLOCK_READ_DATA;
92 		else
93 			bex->es = PNFS_BLOCK_READWRITE_DATA;
94 		bex->soff = (iomap.blkno << 9);
95 		break;
96 	case IOMAP_UNWRITTEN:
97 		if (seg->iomode & IOMODE_RW) {
98 			/*
99 			 * Crack monkey special case from section 2.3.1.
100 			 */
101 			if (args->lg_minlength == 0) {
102 				dprintk("pnfsd: no soup for you!\n");
103 				goto out_layoutunavailable;
104 			}
105 
106 			bex->es = PNFS_BLOCK_INVALID_DATA;
107 			bex->soff = (iomap.blkno << 9);
108 			break;
109 		}
110 		/*FALLTHRU*/
111 	case IOMAP_HOLE:
112 		if (seg->iomode == IOMODE_READ) {
113 			bex->es = PNFS_BLOCK_NONE_DATA;
114 			break;
115 		}
116 		/*FALLTHRU*/
117 	case IOMAP_DELALLOC:
118 	default:
119 		WARN(1, "pnfsd: filesystem returned %d extent\n", iomap.type);
120 		goto out_layoutunavailable;
121 	}
122 
123 	error = nfsd4_set_deviceid(&bex->vol_id, fhp, device_generation);
124 	if (error)
125 		goto out_error;
126 	bex->foff = iomap.offset;
127 	bex->len = iomap.length;
128 
129 	seg->offset = iomap.offset;
130 	seg->length = iomap.length;
131 
132 	dprintk("GET: 0x%llx:0x%llx %d\n", bex->foff, bex->len, bex->es);
133 	return 0;
134 
135 out_error:
136 	seg->length = 0;
137 	return nfserrno(error);
138 out_layoutunavailable:
139 	seg->length = 0;
140 	return nfserr_layoutunavailable;
141 }
142 
143 static __be32
144 nfsd4_block_proc_layoutcommit(struct inode *inode,
145 		struct nfsd4_layoutcommit *lcp)
146 {
147 	loff_t new_size = lcp->lc_last_wr + 1;
148 	struct iattr iattr = { .ia_valid = 0 };
149 	struct iomap *iomaps;
150 	int nr_iomaps;
151 	int error;
152 
153 	nr_iomaps = nfsd4_block_decode_layoutupdate(lcp->lc_up_layout,
154 			lcp->lc_up_len, &iomaps, 1 << inode->i_blkbits);
155 	if (nr_iomaps < 0)
156 		return nfserrno(nr_iomaps);
157 
158 	if (lcp->lc_mtime.tv_nsec == UTIME_NOW ||
159 	    timespec_compare(&lcp->lc_mtime, &inode->i_mtime) < 0)
160 		lcp->lc_mtime = current_fs_time(inode->i_sb);
161 	iattr.ia_valid |= ATTR_ATIME | ATTR_CTIME | ATTR_MTIME;
162 	iattr.ia_atime = iattr.ia_ctime = iattr.ia_mtime = lcp->lc_mtime;
163 
164 	if (new_size > i_size_read(inode)) {
165 		iattr.ia_valid |= ATTR_SIZE;
166 		iattr.ia_size = new_size;
167 	}
168 
169 	error = inode->i_sb->s_export_op->commit_blocks(inode, iomaps,
170 			nr_iomaps, &iattr);
171 	kfree(iomaps);
172 	return nfserrno(error);
173 }
174 
175 const struct nfsd4_layout_ops bl_layout_ops = {
176 	/*
177 	 * Pretend that we send notification to the client.  This is a blatant
178 	 * lie to force recent Linux clients to cache our device IDs.
179 	 * We rarely ever change the device ID, so the harm of leaking deviceids
180 	 * for a while isn't too bad.  Unfortunately RFC5661 is a complete mess
181 	 * in this regard, but I filed errata 4119 for this a while ago, and
182 	 * hopefully the Linux client will eventually start caching deviceids
183 	 * without this again.
184 	 */
185 	.notify_types		=
186 			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
187 	.proc_getdeviceinfo	= nfsd4_block_proc_getdeviceinfo,
188 	.encode_getdeviceinfo	= nfsd4_block_encode_getdeviceinfo,
189 	.proc_layoutget		= nfsd4_block_proc_layoutget,
190 	.encode_layoutget	= nfsd4_block_encode_layoutget,
191 	.proc_layoutcommit	= nfsd4_block_proc_layoutcommit,
192 };
193