1 /*
2 * Copyright (c) 1989, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 *
7 * @(#)lfs_balloc.c 8.4 (Berkeley) 05/08/95
8 */
9 #include <sys/param.h>
10 #include <sys/buf.h>
11 #include <sys/proc.h>
12 #include <sys/vnode.h>
13 #include <sys/mount.h>
14 #include <sys/resourcevar.h>
15 #include <sys/trace.h>
16
17 #include <miscfs/specfs/specdev.h>
18
19 #include <ufs/ufs/quota.h>
20 #include <ufs/ufs/inode.h>
21 #include <ufs/ufs/ufsmount.h>
22
23 #include <ufs/lfs/lfs.h>
24 #include <ufs/lfs/lfs_extern.h>
25
26 int
lfs_balloc(vp,offset,iosize,lbn,bpp)27 lfs_balloc(vp, offset, iosize, lbn, bpp)
28 struct vnode *vp;
29 int offset;
30 u_long iosize;
31 ufs_daddr_t lbn;
32 struct buf **bpp;
33 {
34 struct buf *ibp, *bp;
35 struct inode *ip;
36 struct lfs *fs;
37 struct indir indirs[NIADDR+2];
38 ufs_daddr_t daddr, lastblock;
39 int bb; /* number of disk blocks in a block disk blocks */
40 int error, frags, i, nsize, osize, num;
41
42 ip = VTOI(vp);
43 fs = ip->i_lfs;
44
45 /*
46 * Three cases: it's a block beyond the end of file, it's a block in
47 * the file that may or may not have been assigned a disk address or
48 * we're writing an entire block. Note, if the daddr is unassigned,
49 * the block might still have existed in the cache (if it was read
50 * or written earlier). If it did, make sure we don't count it as a
51 * new block or zero out its contents. If it did not, make sure
52 * we allocate any necessary indirect blocks.
53 * If we are writing a block beyond the end of the file, we need to
54 * check if the old last block was a fragment. If it was, we need
55 * to rewrite it.
56 */
57
58 *bpp = NULL;
59 if (error = ufs_bmaparray(vp, lbn, &daddr, &indirs[0], &num, NULL ))
60 return (error);
61
62 /* Check for block beyond end of file and fragment extension needed. */
63 lastblock = lblkno(fs, ip->i_size);
64 if (lastblock < NDADDR && lastblock < lbn) {
65 osize = blksize(fs, ip, lastblock);
66 if (osize < fs->lfs_bsize && osize > 0) {
67 if (error = lfs_fragextend(vp, osize, fs->lfs_bsize,
68 lastblock, &bp))
69 return(error);
70 ip->i_size = (lastblock + 1) * fs->lfs_bsize;
71 vnode_pager_setsize(vp, (u_long)ip->i_size);
72 ip->i_flag |= IN_CHANGE | IN_UPDATE;
73 VOP_BWRITE(bp);
74 }
75 }
76
77 bb = VFSTOUFS(vp->v_mount)->um_seqinc;
78 if (daddr == UNASSIGNED)
79 /* May need to allocate indirect blocks */
80 for (i = 1; i < num; ++i)
81 if (!indirs[i].in_exists) {
82 ibp = getblk(vp, indirs[i].in_lbn, fs->lfs_bsize,
83 0, 0);
84 if ((ibp->b_flags & (B_DONE | B_DELWRI)))
85 panic ("Indirect block should not exist");
86
87 if (!ISSPACE(fs, bb, curproc->p_ucred)){
88 ibp->b_flags |= B_INVAL;
89 brelse(ibp);
90 return(ENOSPC);
91 } else {
92 ip->i_blocks += bb;
93 ip->i_lfs->lfs_bfree -= bb;
94 clrbuf(ibp);
95 if(error = VOP_BWRITE(ibp))
96 return(error);
97 }
98 }
99
100 /*
101 * If the block we are writing is a direct block, it's the last
102 * block in the file, and offset + iosize is less than a full
103 * block, we can write one or more fragments. There are two cases:
104 * the block is brand new and we should allocate it the correct
105 * size or it already exists and contains some fragments and
106 * may need to extend it.
107 */
108 if (lbn < NDADDR && lblkno(fs, ip->i_size) == lbn) {
109 nsize = fragroundup(fs, offset + iosize);
110 frags = numfrags(fs, nsize);
111 bb = fragstodb(fs, frags);
112 if (lblktosize(fs, lbn) == ip->i_size)
113 /* Brand new block or fragment */
114 *bpp = bp = getblk(vp, lbn, nsize, 0, 0);
115 else {
116 /* Extend existing block */
117 if (error = lfs_fragextend(vp, (int)blksize(fs, ip, lbn),
118 nsize, lbn, &bp))
119 return(error);
120 *bpp = bp;
121 }
122 } else {
123 /*
124 * Get the existing block from the cache either because the
125 * block is 1) not a direct block or because it's not the last
126 * block in the file.
127 */
128 frags = dbtofrags(fs, bb);
129 *bpp = bp = getblk(vp, lbn, blksize(fs, ip, lbn), 0, 0);
130 }
131
132 /*
133 * The block we are writing may be a brand new block
134 * in which case we need to do accounting (i.e. check
135 * for free space and update the inode number of blocks.
136 */
137 if (!(bp->b_flags & (B_CACHE | B_DONE | B_DELWRI))) {
138 if (daddr == UNASSIGNED)
139 if (!ISSPACE(fs, bb, curproc->p_ucred)) {
140 bp->b_flags |= B_INVAL;
141 brelse(bp);
142 return(ENOSPC);
143 } else {
144 ip->i_blocks += bb;
145 ip->i_lfs->lfs_bfree -= bb;
146 if (iosize != fs->lfs_bsize)
147 clrbuf(bp);
148 }
149 else if (iosize == fs->lfs_bsize)
150 /* Optimization: I/O is unnecessary. */
151 bp->b_blkno = daddr;
152 else {
153 /*
154 * We need to read the block to preserve the
155 * existing bytes.
156 */
157 bp->b_blkno = daddr;
158 bp->b_flags |= B_READ;
159 VOP_STRATEGY(bp);
160 return(biowait(bp));
161 }
162 }
163 return (0);
164 }
165
166 lfs_fragextend(vp, osize, nsize, lbn, bpp)
167 struct vnode *vp;
168 int osize;
169 int nsize;
170 daddr_t lbn;
171 struct buf **bpp;
172 {
173 struct inode *ip;
174 struct lfs *fs;
175 long bb;
176 int error;
177
178 ip = VTOI(vp);
179 fs = ip->i_lfs;
180 bb = (long)fragstodb(fs, numfrags(fs, nsize - osize));
181 if (!ISSPACE(fs, bb, curproc->p_ucred)) {
182 return(ENOSPC);
183 }
184
185 if (error = bread(vp, lbn, osize, NOCRED, bpp)) {
186 brelse(*bpp);
187 return(error);
188 }
189 #ifdef QUOTA
190 if (error = chkdq(ip, bb, curproc->p_ucred, 0)) {
191 brelse(*bpp);
192 return (error);
193 }
194 #endif
195 ip->i_blocks += bb;
196 ip->i_flag |= IN_CHANGE | IN_UPDATE;
197 fs->lfs_bfree -= fragstodb(fs, numfrags(fs, (nsize - osize)));
198 allocbuf(*bpp, nsize);
199 bzero((char *)((*bpp)->b_data) + osize, (u_int)(nsize - osize));
200 return(0);
201 }
202