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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39 * @(#)ufs_readwrite.c 8.7 (Berkeley) 1/21/94
40 * $FreeBSD: src/sys/gnu/ext2fs/ext2_readwrite.c,v 1.18.2.2 2000/12/22 18:44:33 dillon Exp $
43 #define BLKSIZE(a, b, c) blksize(a, b, c)
44 #define FS struct ext2_sb_info
48 * Vnode op for reading.
50 * ext2_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
51 * struct ucred *a_cred)
55 ext2_read(struct vop_read_args *ap)
65 long size, xfersize, blkoffset;
66 int error, orig_resid;
67 int seqcount = ap->a_ioflag >> 16;
74 if (uio->uio_rw != UIO_READ)
75 panic("ext2_read: mode");
77 if (vp->v_type == VLNK) {
78 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
79 panic("ext2_read: short symlink");
80 } else if (vp->v_type != VREG && vp->v_type != VDIR)
81 panic("ext2_read: type %d", vp->v_type);
85 if ((u_quad_t)uio->uio_offset > fs->fs_maxfilesize)
89 orig_resid = uio->uio_resid;
90 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
91 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
93 lbn = lblkno(fs, uio->uio_offset);
95 nextloffset = lblktodoff(fs, nextlbn);
96 size = BLKSIZE(fs, ip, lbn);
97 blkoffset = blkoff(fs, uio->uio_offset);
99 xfersize = fs->s_frag_size - blkoffset;
100 if (uio->uio_resid < xfersize)
101 xfersize = uio->uio_resid;
102 if (bytesinfile < xfersize)
103 xfersize = bytesinfile;
105 if (nextloffset >= ip->i_size) {
106 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
107 } else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
108 error = cluster_read(vp, (off_t)ip->i_size,
109 lblktodoff(fs, lbn), size,
111 (ap->a_ioflag >> 16) * BKVASIZE,
113 } else if (seqcount > 1) {
114 int nextsize = BLKSIZE(fs, ip, nextlbn);
115 error = breadn(vp, lblktodoff(fs, lbn),
116 size, &nextloffset, &nextsize, 1, &bp);
118 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
127 * We should only get non-zero b_resid when an I/O error
128 * has occurred, which should cause us to break above.
129 * However, if the short read did not cause an error,
130 * then we want to ensure that we do not uiomove bad
131 * or uninitialized data.
134 if (size < xfersize) {
139 error = uiomove((char *)bp->b_data + blkoffset,
148 if (orig_resid > 0 && (error == 0 || uio->uio_resid != orig_resid) &&
149 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
150 ip->i_flag |= IN_ACCESS;
155 * Vnode op for writing.
157 * ext2_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
158 * struct ucred *a_cred)
161 ext2_write(struct vop_write_args *ap)
172 int blkoffset, error, flags, ioflag, resid, size, xfersize;
174 ioflag = ap->a_ioflag;
175 seqcount = ap->a_ioflag >> 16;
181 if (uio->uio_rw != UIO_WRITE)
182 panic("ext2_write: mode");
185 switch (vp->v_type) {
187 if (ioflag & IO_APPEND)
188 uio->uio_offset = ip->i_size;
189 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
195 if ((ioflag & IO_SYNC) == 0)
196 panic("ext2_write: nonsync dir write");
199 panic("ext2_write: type");
204 if (uio->uio_offset < 0 ||
205 (u_quad_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
209 * Maybe this should be above the vnode op call, but so long as
210 * file servers have no limits, I don't think it matters.
213 if (vp->v_type == VREG && td && td->td_proc &&
214 uio->uio_offset + uio->uio_resid >
215 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
216 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
220 resid = uio->uio_resid;
222 flags = ioflag & IO_SYNC ? B_SYNC : 0;
224 for (error = 0; uio->uio_resid > 0;) {
225 lbn = lblkno(fs, uio->uio_offset);
226 blkoffset = blkoff(fs, uio->uio_offset);
227 xfersize = fs->s_frag_size - blkoffset;
228 if (uio->uio_resid < xfersize)
229 xfersize = uio->uio_resid;
231 if (uio->uio_offset + xfersize > ip->i_size)
232 vnode_pager_setsize(vp, uio->uio_offset + xfersize);
235 * Avoid a data-consistency race between write() and mmap()
236 * by ensuring that newly allocated blocks are zerod. The
237 * race can occur even in the case where the write covers
240 * Just set B_CLRBUF unconditionally, even if the write
241 * covers the whole block. This also handles the UIO_NOCOPY
242 * case. See ffs_write() in ufs for a more sophisticated
246 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
247 ap->a_cred, &bp, flags);
251 if (uio->uio_offset + xfersize > ip->i_size) {
252 ip->i_size = uio->uio_offset + xfersize;
255 size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
259 error = uiomove((char *)bp->b_data + blkoffset,
261 if ((ioflag & IO_VMIO) &&
262 LIST_FIRST(&bp->b_dep) == NULL) /* in ext2fs? */
263 bp->b_flags |= B_RELBUF;
265 if (ioflag & IO_SYNC) {
267 } else if (xfersize + blkoffset == fs->s_frag_size) {
268 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
269 bp->b_flags |= B_CLUSTEROK;
270 cluster_write(bp, (off_t)ip->i_size, vp->v_mount->mnt_stat.f_iosize, seqcount);
275 bp->b_flags |= B_CLUSTEROK;
278 if (error || xfersize == 0)
280 ip->i_flag |= IN_CHANGE | IN_UPDATE;
283 * If we successfully wrote any data, and we are not the superuser
284 * we clear the setuid and setgid bits as a precaution against
287 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
288 ip->i_mode &= ~(ISUID | ISGID);
290 if (ioflag & IO_UNIT) {
291 EXT2_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred);
292 uio->uio_offset -= resid - uio->uio_resid;
293 uio->uio_resid = resid;
295 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC))
296 error = EXT2_UPDATE(vp, 1);