2 * modified for Lites 1.1
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
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35 * @(#)ufs_readwrite.c 8.7 (Berkeley) 1/21/94
36 * $FreeBSD: src/sys/gnu/ext2fs/ext2_readwrite.c,v 1.18.2.2 2000/12/22 18:44:33 dillon Exp $
39 #define BLKSIZE(a, b, c) blksize(a, b, c)
42 * Vnode op for reading.
44 * ext2_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
45 * struct ucred *a_cred)
49 ext2_read(struct vop_read_args *ap)
54 struct ext2_sb_info *fs;
59 long size, xfersize, blkoffset;
60 int error, orig_resid;
61 int seqcount = ap->a_ioflag >> IO_SEQSHIFT;
68 if (uio->uio_rw != UIO_READ)
69 panic("ext2_read: mode");
71 if (vp->v_type == VLNK) {
72 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
73 panic("ext2_read: short symlink");
74 } else if (vp->v_type != VREG && vp->v_type != VDIR)
75 panic("ext2_read: type %d", vp->v_type);
79 if ((u_quad_t)uio->uio_offset > fs->fs_maxfilesize)
83 orig_resid = uio->uio_resid;
84 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
85 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
87 lbn = lblkno(fs, uio->uio_offset);
89 nextloffset = lblktodoff(fs, nextlbn);
90 size = BLKSIZE(fs, ip, lbn);
91 blkoffset = blkoff(fs, uio->uio_offset);
93 xfersize = fs->s_frag_size - blkoffset;
94 if (uio->uio_resid < xfersize)
95 xfersize = uio->uio_resid;
96 if (bytesinfile < xfersize)
97 xfersize = bytesinfile;
99 if (nextloffset >= ip->i_size) {
100 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
101 } else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
102 error = cluster_read(vp, (off_t)ip->i_size,
103 lblktodoff(fs, lbn), size,
105 (ap->a_ioflag >> IO_SEQSHIFT) * MAXBSIZE,
107 } else if (seqcount > 1) {
108 int nextsize = BLKSIZE(fs, ip, nextlbn);
109 error = breadn(vp, lblktodoff(fs, lbn),
110 size, &nextloffset, &nextsize, 1, &bp);
112 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
121 * We should only get non-zero b_resid when an I/O error
122 * has occurred, which should cause us to break above.
123 * However, if the short read did not cause an error,
124 * then we want to ensure that we do not uiomove bad
125 * or uninitialized data.
128 if (size < xfersize) {
133 error = uiomove((char *)bp->b_data + blkoffset,
142 if (orig_resid > 0 && (error == 0 || uio->uio_resid != orig_resid) &&
143 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
144 ip->i_flag |= IN_ACCESS;
149 * Vnode op for writing.
151 * ext2_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
152 * struct ucred *a_cred)
155 ext2_write(struct vop_write_args *ap)
160 struct ext2_sb_info *fs;
166 int blkoffset, error, flags, ioflag, resid, size, xfersize;
168 ioflag = ap->a_ioflag;
169 seqcount = ap->a_ioflag >> IO_SEQSHIFT;
175 if (uio->uio_rw != UIO_WRITE)
176 panic("ext2_write: mode");
179 switch (vp->v_type) {
181 if (ioflag & IO_APPEND)
182 uio->uio_offset = ip->i_size;
183 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
189 if ((ioflag & IO_SYNC) == 0)
190 panic("ext2_write: nonsync dir write");
193 panic("ext2_write: type");
198 if (uio->uio_offset < 0 ||
199 (u_quad_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
203 * Maybe this should be above the vnode op call, but so long as
204 * file servers have no limits, I don't think it matters.
207 if (vp->v_type == VREG && td && td->td_proc &&
208 uio->uio_offset + uio->uio_resid >
209 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
210 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
214 resid = uio->uio_resid;
216 flags = ioflag & IO_SYNC ? B_SYNC : 0;
218 for (error = 0; uio->uio_resid > 0;) {
219 lbn = lblkno(fs, uio->uio_offset);
220 blkoffset = blkoff(fs, uio->uio_offset);
221 xfersize = fs->s_frag_size - blkoffset;
222 if (uio->uio_resid < xfersize)
223 xfersize = uio->uio_resid;
225 if (uio->uio_offset + xfersize > ip->i_size)
226 vnode_pager_setsize(vp, uio->uio_offset + xfersize);
229 * Avoid a data-consistency race between write() and mmap()
230 * by ensuring that newly allocated blocks are zerod. The
231 * race can occur even in the case where the write covers
234 * Just set B_CLRBUF unconditionally, even if the write
235 * covers the whole block. This also handles the UIO_NOCOPY
236 * case. See ffs_write() in ufs for a more sophisticated
240 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
241 ap->a_cred, &bp, flags);
245 if (uio->uio_offset + xfersize > ip->i_size) {
246 ip->i_size = uio->uio_offset + xfersize;
249 size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
253 error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);
254 if ((ioflag & IO_VMIO) &&
255 LIST_FIRST(&bp->b_dep) == NULL) /* in ext2fs? */
256 bp->b_flags |= B_RELBUF;
258 if (ioflag & IO_SYNC) {
260 } else if (xfersize + blkoffset == fs->s_frag_size) {
261 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
262 bp->b_flags |= B_CLUSTEROK;
263 cluster_write(bp, (off_t)ip->i_size, vp->v_mount->mnt_stat.f_iosize, seqcount);
268 bp->b_flags |= B_CLUSTEROK;
271 if (error || xfersize == 0)
273 ip->i_flag |= IN_CHANGE | IN_UPDATE;
276 * If we successfully wrote any data, and we are not the superuser
277 * we clear the setuid and setgid bits as a precaution against
280 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
281 ip->i_mode &= ~(ISUID | ISGID);
283 if (ioflag & IO_UNIT) {
284 EXT2_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred);
285 uio->uio_offset -= resid - uio->uio_resid;
286 uio->uio_resid = resid;
288 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC))
289 error = EXT2_UPDATE(vp, 1);