Bug Summary

File:ufs/ext2fs/ext2fs_balloc.c
Warning:line 110, column 2
Value stored to 'pref' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple amd64-unknown-openbsd7.0 -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name ext2fs_balloc.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -mrelocation-model static -mframe-pointer=all -relaxed-aliasing -fno-rounding-math -mconstructor-aliases -ffreestanding -mcmodel=kernel -target-cpu x86-64 -target-feature +retpoline-indirect-calls -target-feature +retpoline-indirect-branches -target-feature -sse2 -target-feature -sse -target-feature -3dnow -target-feature -mmx -target-feature +save-args -disable-red-zone -no-implicit-float -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -nostdsysteminc -nobuiltininc -resource-dir /usr/local/lib/clang/13.0.0 -I /usr/src/sys -I /usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -I /usr/src/sys/arch -I /usr/src/sys/dev/pci/drm/include -I /usr/src/sys/dev/pci/drm/include/uapi -I /usr/src/sys/dev/pci/drm/amd/include/asic_reg -I /usr/src/sys/dev/pci/drm/amd/include -I /usr/src/sys/dev/pci/drm/amd/amdgpu -I /usr/src/sys/dev/pci/drm/amd/display -I /usr/src/sys/dev/pci/drm/amd/display/include -I /usr/src/sys/dev/pci/drm/amd/display/dc -I /usr/src/sys/dev/pci/drm/amd/display/amdgpu_dm -I /usr/src/sys/dev/pci/drm/amd/pm/inc -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu11 -I /usr/src/sys/dev/pci/drm/amd/pm/swsmu/smu12 -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/hwmgr -I /usr/src/sys/dev/pci/drm/amd/pm/powerplay/smumgr -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc -I /usr/src/sys/dev/pci/drm/amd/display/dc/inc/hw -I /usr/src/sys/dev/pci/drm/amd/display/dc/clk_mgr -I /usr/src/sys/dev/pci/drm/amd/display/modules/inc -I /usr/src/sys/dev/pci/drm/amd/display/modules/hdcp -I /usr/src/sys/dev/pci/drm/amd/display/dmub/inc -I /usr/src/sys/dev/pci/drm/i915 -D DDB -D DIAGNOSTIC -D KTRACE -D ACCOUNTING -D KMEMSTATS -D PTRACE -D POOL_DEBUG -D CRYPTO -D SYSVMSG -D SYSVSEM -D SYSVSHM -D UVM_SWAP_ENCRYPT -D FFS -D FFS2 -D FFS_SOFTUPDATES -D UFS_DIRHASH -D QUOTA -D EXT2FS -D MFS -D NFSCLIENT -D NFSSERVER -D CD9660 -D UDF -D MSDOSFS -D FIFO -D FUSE -D SOCKET_SPLICE -D TCP_ECN -D TCP_SIGNATURE -D INET6 -D IPSEC -D PPP_BSDCOMP -D PPP_DEFLATE -D PIPEX -D MROUTING -D MPLS -D BOOT_CONFIG -D USER_PCICONF -D APERTURE -D MTRR -D NTFS -D HIBERNATE -D PCIVERBOSE -D USBVERBOSE -D WSDISPLAY_COMPAT_USL -D WSDISPLAY_COMPAT_RAWKBD -D WSDISPLAY_DEFAULTSCREENS=6 -D X86EMU -D ONEWIREVERBOSE -D MULTIPROCESSOR -D MAXUSERS=80 -D _KERNEL -D CONFIG_DRM_AMD_DC_DCN3_0 -O2 -Wno-pointer-sign -Wno-address-of-packed-member -Wno-constant-conversion -Wno-unused-but-set-variable -Wno-gnu-folding-constant -fdebug-compilation-dir=/usr/src/sys/arch/amd64/compile/GENERIC.MP/obj -ferror-limit 19 -fwrapv -D_RET_PROTECTOR -ret-protector -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -fno-builtin-malloc -fno-builtin-calloc -fno-builtin-realloc -fno-builtin-valloc -fno-builtin-free -fno-builtin-strdup -fno-builtin-strndup -analyzer-output=html -faddrsig -o /usr/obj/sys/arch/amd64/compile/GENERIC.MP/scan-build/2022-01-12-131800-47421-1 -x c /usr/src/sys/ufs/ext2fs/ext2fs_balloc.c
1/* $OpenBSD: ext2fs_balloc.c,v 1.27 2019/07/19 00:24:31 cheloha Exp $ */
2/* $NetBSD: ext2fs_balloc.c,v 1.10 2001/07/04 21:16:01 chs Exp $ */
3
4/*
5 * Copyright (c) 1997 Manuel Bouyer.
6 * Copyright (c) 1982, 1986, 1989, 1993
7 * The Regents of the University of California. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)ffs_balloc.c 8.4 (Berkeley) 9/23/93
34 * Modified for ext2fs by Manuel Bouyer.
35 */
36
37#include <sys/param.h>
38#include <sys/systm.h>
39#include <sys/buf.h>
40#include <sys/vnode.h>
41
42#include <ufs/ufs/quota.h>
43#include <ufs/ufs/inode.h>
44#include <ufs/ufs/ufs_extern.h>
45
46#include <ufs/ext2fs/ext2fs.h>
47#include <ufs/ext2fs/ext2fs_extern.h>
48
49/*
50 * Balloc defines the structure of file system storage
51 * by allocating the physical blocks on a device given
52 * the inode and the logical block number in a file.
53 */
54int
55ext2fs_buf_alloc(struct inode *ip, u_int32_t bn, int size, struct ucred *cred,
56 struct buf **bpp, int flags)
57{
58 struct m_ext2fs *fs;
59 struct buf *bp, *nbp;
60 struct vnode *vp = ITOV(ip)((ip)->i_vnode);
61 struct indir indirs[NIADDR3 + 2];
62 u_int32_t nb, newb, *bap;
63 int num, i, error;
64 u_int deallocated;
65 u_int32_t *allocib, *blkp, *allocblk, allociblk[NIADDR3 + 1];
66 int unwindidx = -1;
67 daddr_t lbn, pref;
68
69 *bpp = NULL((void *)0);
70 fs = ip->i_e2fsinode_u.e2fs;
71 lbn = bn;
72
73 /*
74 * The first NDADDR blocks are direct blocks
75 */
76 if (bn < NDADDR12) {
77 nb = letoh32(ip->i_e2fs_blocks[bn])((__uint32_t)(ip->dinode_u.e2fs_din->e2di_blocks[bn]));
78 if (nb != 0) {
79 error = bread(vp, bn, fs->e2fs_bsize, &bp);
80 if (error) {
81 brelse(bp);
82 return (error);
83 }
84 *bpp = bp;
85 return (0);
86 }
87
88 /*
89 * allocate a new direct block.
90 */
91 error = ext2fs_alloc(ip, bn,
92 ext2fs_blkpref(ip, bn, (int)bn, &ip->i_e2fs_blocksdinode_u.e2fs_din->e2di_blocks[0]),
93 cred, &newb);
94 if (error)
95 return (error);
96 ip->i_e2fs_last_lblkinode_ext.e2fs.ext2fs_last_lblk = lbn;
97 ip->i_e2fs_last_blkinode_ext.e2fs.ext2fs_last_blk = newb;
98 ip->i_e2fs_blocksdinode_u.e2fs_din->e2di_blocks[bn] = htole32(newb)((__uint32_t)(newb));
99 ip->i_flag |= IN_CHANGE0x0002 | IN_UPDATE0x0004;
100 bp = getblk(vp, bn, fs->e2fs_bsize, 0, INFSLP0xffffffffffffffffULL);
101 bp->b_blkno = fsbtodb(fs, newb)((newb) << (fs)->e2fs_fsbtodb);
102 if (flags & B_CLRBUF0x01)
103 clrbuf(bp){ __builtin_bzero(((bp)->b_data), ((bp)->b_bcount)); (bp
)->b_resid = 0; }
;
104 *bpp = bp;
105 return (0);
106 }
107 /*
108 * Determine the number of levels of indirection.
109 */
110 pref = 0;
Value stored to 'pref' is never read
111 if ((error = ufs_getlbns(vp, bn, indirs, &num)) != 0)
112 return(error);
113#ifdef DIAGNOSTIC1
114 if (num < 1)
115 panic ("ext2fs_balloc: ufs_getlbns returned indirect block");
116#endif
117 /*
118 * Fetch the first indirect block allocating if necessary.
119 */
120 --num;
121 nb = letoh32(ip->i_e2fs_blocks[NDADDR + indirs[0].in_off])((__uint32_t)(ip->dinode_u.e2fs_din->e2di_blocks[12 + indirs
[0].in_off]))
;
122 allocib = NULL((void *)0);
123 allocblk = allociblk;
124 if (nb == 0) {
125 pref = ext2fs_blkpref(ip, lbn, 0, NULL((void *)0));
126 error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
127 if (error)
128 return (error);
129 nb = newb;
130 *allocblk++ = nb;
131 ip->i_e2fs_last_blkinode_ext.e2fs.ext2fs_last_blk = newb;
132 bp = getblk(vp, indirs[1].in_lbn, fs->e2fs_bsize, 0, INFSLP0xffffffffffffffffULL);
133 bp->b_blkno = fsbtodb(fs, newb)((newb) << (fs)->e2fs_fsbtodb);
134 clrbuf(bp){ __builtin_bzero(((bp)->b_data), ((bp)->b_bcount)); (bp
)->b_resid = 0; }
;
135 /*
136 * Write synchronously so that indirect blocks
137 * never point at garbage.
138 */
139 if ((error = bwrite(bp)) != 0)
140 goto fail;
141 unwindidx = 0;
142 allocib = &ip->i_e2fs_blocksdinode_u.e2fs_din->e2di_blocks[NDADDR12 + indirs[0].in_off];
143 *allocib = htole32(newb)((__uint32_t)(newb));
144 ip->i_flag |= IN_CHANGE0x0002 | IN_UPDATE0x0004;
145 }
146 /*
147 * Fetch through the indirect blocks, allocating as necessary.
148 */
149 for (i = 1;;) {
150 error = bread(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize, &bp);
151 if (error) {
152 brelse(bp);
153 goto fail;
154 }
155 bap = (u_int32_t *)bp->b_data;
156 nb = letoh32(bap[indirs[i].in_off])((__uint32_t)(bap[indirs[i].in_off]));
157 if (i == num)
158 break;
159 i++;
160 if (nb != 0) {
161 brelse(bp);
162 continue;
163 }
164 pref = ext2fs_blkpref(ip, lbn, 0, NULL((void *)0));
165 error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
166 if (error) {
167 brelse(bp);
168 goto fail;
169 }
170 nb = newb;
171 *allocblk++ = nb;
172 ip->i_e2fs_last_blkinode_ext.e2fs.ext2fs_last_blk = newb;
173 nbp = getblk(vp, indirs[i].in_lbn, fs->e2fs_bsize, 0, INFSLP0xffffffffffffffffULL);
174 nbp->b_blkno = fsbtodb(fs, nb)((nb) << (fs)->e2fs_fsbtodb);
175 clrbuf(nbp){ __builtin_bzero(((nbp)->b_data), ((nbp)->b_bcount)); (
nbp)->b_resid = 0; }
;
176 /*
177 * Write synchronously so that indirect blocks
178 * never point at garbage.
179 */
180 if ((error = bwrite(nbp)) != 0) {
181 brelse(bp);
182 goto fail;
183 }
184 if (unwindidx < 0)
185 unwindidx = i - 1;
186 bap[indirs[i - 1].in_off] = htole32(nb)((__uint32_t)(nb));
187 /*
188 * If required, write synchronously, otherwise use
189 * delayed write.
190 */
191 if (flags & B_SYNC0x02) {
192 bwrite(bp);
193 } else {
194 bdwrite(bp);
195 }
196 }
197 /*
198 * Get the data block, allocating if necessary.
199 */
200 if (nb == 0) {
201 pref = ext2fs_blkpref(ip, lbn, indirs[num].in_off, bap);
202 error = ext2fs_alloc(ip, lbn, pref, cred, &newb);
203 if (error) {
204 brelse(bp);
205 goto fail;
206 }
207 nb = newb;
208 *allocblk++ = nb;
209 ip->i_e2fs_last_lblkinode_ext.e2fs.ext2fs_last_lblk = lbn;
210 ip->i_e2fs_last_blkinode_ext.e2fs.ext2fs_last_blk = newb;
211 bap[indirs[num].in_off] = htole32(nb)((__uint32_t)(nb));
212 /*
213 * If required, write synchronously, otherwise use
214 * delayed write.
215 */
216 if (flags & B_SYNC0x02) {
217 bwrite(bp);
218 } else {
219 bdwrite(bp);
220 }
221 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, INFSLP0xffffffffffffffffULL);
222 nbp->b_blkno = fsbtodb(fs, nb)((nb) << (fs)->e2fs_fsbtodb);
223 if (flags & B_CLRBUF0x01)
224 clrbuf(nbp){ __builtin_bzero(((nbp)->b_data), ((nbp)->b_bcount)); (
nbp)->b_resid = 0; }
;
225 *bpp = nbp;
226 return (0);
227 }
228 brelse(bp);
229 if (flags & B_CLRBUF0x01) {
230 error = bread(vp, lbn, (int)fs->e2fs_bsize, &nbp);
231 if (error) {
232 brelse(nbp);
233 goto fail;
234 }
235 } else {
236 nbp = getblk(vp, lbn, fs->e2fs_bsize, 0, INFSLP0xffffffffffffffffULL);
237 nbp->b_blkno = fsbtodb(fs, nb)((nb) << (fs)->e2fs_fsbtodb);
238 }
239
240 *bpp = nbp;
241 return (0);
242fail:
243 /*
244 * If we have failed part way through block allocation, we
245 * have to deallocate any indirect blocks that we have allocated.
246 */
247 for (deallocated = 0, blkp = allociblk; blkp < allocblk; blkp++) {
248 ext2fs_blkfree(ip, *blkp);
249 deallocated += fs->e2fs_bsize;
250 }
251 if (unwindidx >= 0) {
252 if (unwindidx == 0) {
253 *allocib = 0;
254 } else {
255 int r;
256
257 r = bread(vp, indirs[unwindidx].in_lbn,
258 (int)fs->e2fs_bsize, &bp);
259 if (r) {
260 panic("Could not unwind indirect block, error %d", r);
261 } else {
262 bap = (u_int32_t *)bp->b_data;
263 bap[indirs[unwindidx].in_off] = 0;
264 if (flags & B_SYNC0x02)
265 bwrite(bp);
266 else
267 bdwrite(bp);
268 }
269 }
270 for (i = unwindidx + 1; i <= num; i++) {
271 bp = getblk(vp, indirs[i].in_lbn, (int)fs->e2fs_bsize,
272 0, INFSLP0xffffffffffffffffULL);
273 bp->b_flags |= B_INVAL0x00000800;
274 brelse(bp);
275 }
276 }
277 if (deallocated) {
278 ip->i_e2fs_nblockdinode_u.e2fs_din->e2di_nblock -= btodb(deallocated)((deallocated) >> 9);
279 ip->i_e2fs_flagsdinode_u.e2fs_din->e2di_flags |= IN_CHANGE0x0002 | IN_UPDATE0x0004;
280 }
281 return error;
282}