3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * @(#)ufs_readwrite.c 8.11 (Berkeley) 5/8/95
30 * $FreeBSD: src/sys/ufs/ufs/ufs_readwrite.c,v 1.65.2.14 2003/04/04 22:21:29 tegge Exp $
33 #define BLKSIZE(a, b, c) blksize(a, b, c)
38 #include <vm/vm_object.h>
39 #include <vm/vm_pager.h>
40 #include <vm/vm_map.h>
41 #include <vm/vnode_pager.h>
42 #include <sys/event.h>
43 #include <sys/vmmeter.h>
44 #include <sys/sysctl.h>
45 #include <vm/vm_page2.h>
47 #include "opt_directio.h"
49 #define VN_KNOTE(vp, b) \
50 KNOTE((struct klist *)&vp->v_pollinfo.vpi_kqinfo.ki_note, (b))
53 extern int ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone);
56 SYSCTL_DECL(_vfs_ffs);
59 * Vnode op for reading.
61 * ffs_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
62 * struct ucred *a_cred)
66 ffs_read(struct vop_read_args *ap)
74 int xfersize, blkoffset;
75 int error, orig_resid;
80 seqcount = ap->a_ioflag >> 16;
83 ioflag = ap->a_ioflag;
85 if ((ioflag & IO_DIRECT) != 0) {
88 error = ffs_rawread(vp, uio, &workdone);
89 if (error || workdone)
95 if (uio->uio_rw != UIO_READ)
96 panic("ffs_read: mode");
98 if (vp->v_type == VLNK) {
99 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
100 panic("ffs_read: short symlink");
101 } else if (vp->v_type != VREG && vp->v_type != VDIR)
102 panic("ffs_read: type %d", vp->v_type);
105 if ((uint64_t)uio->uio_offset > fs->fs_maxfilesize)
108 orig_resid = uio->uio_resid;
112 bytesinfile = ip->i_size - uio->uio_offset;
113 if (bytesinfile <= 0) {
114 if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
115 ip->i_flag |= IN_ACCESS;
120 * Ok so we couldn't do it all in one vm trick...
121 * so cycle around trying smaller bites..
123 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
124 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
127 error = ffs_blkatoff_ra(vp, uio->uio_offset, NULL,
133 * If IO_DIRECT then set B_DIRECT for the buffer. This
134 * will cause us to attempt to release the buffer later on
135 * and will cause the buffer cache to attempt to free the
138 if (ioflag & IO_DIRECT)
139 bp->b_flags |= B_DIRECT;
142 * We should only get non-zero b_resid when an I/O error
143 * has occurred, which should cause us to break above.
144 * However, if the short read did not cause an error,
145 * then we want to ensure that we do not uiomove bad
146 * or uninitialized data.
148 * XXX b_resid is only valid when an actual I/O has occured
149 * and may be incorrect if the buffer is B_CACHE or if the
150 * last op on the buffer was a failed write. This KASSERT
151 * is a precursor to removing it from the UFS code.
153 KASSERT(bp->b_resid == 0, ("bp->b_resid != 0"));
156 * Calculate how much data we can copy
158 blkoffset = blkoff(fs, uio->uio_offset);
159 xfersize = bp->b_bufsize - blkoffset;
160 if (xfersize > uio->uio_resid)
161 xfersize = uio->uio_resid;
162 if (xfersize > bytesinfile)
163 xfersize = bytesinfile;
165 panic("ufs_readwrite: impossible xfersize: %d",
170 * otherwise use the general form
172 error = uiomovebp(bp, bp->b_data + blkoffset, xfersize, uio);
177 if ((ioflag & (IO_VMIO|IO_DIRECT)) &&
178 (LIST_FIRST(&bp->b_dep) == NULL)) {
180 * If there are no dependencies, and it's VMIO,
181 * then we don't need the buf, mark it available
182 * for freeing. The VM has the data.
184 bp->b_flags |= B_RELBUF;
188 * Otherwise let whoever
189 * made the request take care of
190 * freeing it. We just queue
191 * it onto another list.
198 * This can only happen in the case of an error
199 * because the loop above resets bp to NULL on each iteration
200 * and on normal completion has not set a new value into it.
201 * so it must have come from a 'break' statement
204 if ((ioflag & (IO_VMIO|IO_DIRECT)) &&
205 (LIST_FIRST(&bp->b_dep) == NULL)) {
206 bp->b_flags |= B_RELBUF;
213 if ((error == 0 || uio->uio_resid != orig_resid) &&
214 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
215 ip->i_flag |= IN_ACCESS;
220 * Vnode op for writing.
222 * ffs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
223 * struct ucred *a_cred)
226 ffs_write(struct vop_write_args *ap)
237 int blkoffset, error, extended, flags, ioflag, resid, size, xfersize;
241 seqcount = ap->a_ioflag >> 16;
242 ioflag = ap->a_ioflag;
248 if (uio->uio_rw != UIO_WRITE)
249 panic("ffs_write: mode");
252 switch (vp->v_type) {
254 if (ioflag & IO_APPEND)
255 uio->uio_offset = ip->i_size;
256 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
262 panic("ffs_write: dir write");
265 panic("ffs_write: type %p %d (%d,%d)", vp, (int)vp->v_type,
266 (int)uio->uio_offset,
272 if (uio->uio_offset < 0 ||
273 (uint64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize) {
277 * Maybe this should be above the vnode op call, but so long as
278 * file servers have no limits, I don't think it matters.
281 if (vp->v_type == VREG && td && td->td_proc &&
282 uio->uio_offset + uio->uio_resid >
283 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
284 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
288 resid = uio->uio_resid;
292 * NOTE! These B_ flags are actually balloc-only flags, not buffer
293 * flags. They are similar to the BA_ flags in fbsd.
295 if (seqcount > B_SEQMAX)
296 flags = B_SEQMAX << B_SEQSHIFT;
298 flags = seqcount << B_SEQSHIFT;
299 if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
302 for (error = 0; uio->uio_resid > 0;) {
303 lbn = lblkno(fs, uio->uio_offset);
304 blkoffset = blkoff(fs, uio->uio_offset);
305 xfersize = fs->fs_bsize - blkoffset;
306 if (uio->uio_resid < xfersize)
307 xfersize = uio->uio_resid;
309 if (uio->uio_offset + xfersize > ip->i_size) {
310 nsize = uio->uio_offset + xfersize;
311 nvnode_pager_setsize(vp, nsize,
312 blkoffresize(fs, nsize), blkoff(fs, nsize));
317 * If doing a dummy write to flush the buffer for a
318 * putpages we must perform a read-before-write to
319 * fill in any missing spots and clear any invalid
320 * areas. Otherwise a multi-page buffer may not properly
323 * We must clear any invalid areas
325 if (uio->uio_segflg == UIO_NOCOPY) {
326 error = ffs_blkatoff(vp, uio->uio_offset, NULL, &bp);
334 * We must clear invalid areas.
336 if (xfersize < fs->fs_bsize || uio->uio_segflg == UIO_NOCOPY)
340 /* XXX is uio->uio_offset the right thing here? */
341 error = VOP_BALLOC(vp, uio->uio_offset, xfersize,
342 ap->a_cred, flags, &bp);
346 * If the buffer is not valid and we did not clear garbage
347 * out above, we have to do so here even though the write
348 * covers the entire buffer in order to avoid a mmap()/write
349 * race where another process may see the garbage prior to
350 * the uiomove() for a write replacing it.
352 if ((bp->b_flags & B_CACHE) == 0 && (flags & B_CLRBUF) == 0)
354 if (ioflag & IO_DIRECT)
355 bp->b_flags |= B_DIRECT;
356 if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
357 bp->b_flags |= B_NOCACHE;
359 if (uio->uio_offset + xfersize > ip->i_size) {
360 ip->i_size = uio->uio_offset + xfersize;
364 size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
368 error = uiomovebp(bp, bp->b_data + blkoffset, xfersize, uio);
369 if ((ioflag & (IO_VMIO|IO_DIRECT)) &&
370 (LIST_FIRST(&bp->b_dep) == NULL)) {
371 bp->b_flags |= B_RELBUF;
375 * If IO_SYNC each buffer is written synchronously. Otherwise
376 * if we have a severe page deficiency write the buffer
377 * asynchronously. Otherwise try to cluster, and if that
378 * doesn't do it then either do an async write (if O_DIRECT),
379 * or a delayed write (if not).
382 if (ioflag & IO_SYNC) {
384 } else if (vm_page_count_severe() ||
385 buf_dirty_count_severe() ||
386 (ioflag & IO_ASYNC)) {
387 bp->b_flags |= B_CLUSTEROK;
389 } else if (xfersize + blkoffset == fs->fs_bsize) {
390 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
391 bp->b_flags |= B_CLUSTEROK;
392 cluster_write(bp, (off_t)ip->i_size, fs->fs_bsize, seqcount);
396 } else if (ioflag & IO_DIRECT) {
397 bp->b_flags |= B_CLUSTEROK;
400 bp->b_flags |= B_CLUSTEROK;
403 if (error || xfersize == 0)
405 ip->i_flag |= IN_CHANGE | IN_UPDATE;
408 * If we successfully wrote any data, and we are not the superuser
409 * we clear the setuid and setgid bits as a precaution against
412 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
413 ip->i_mode &= ~(ISUID | ISGID);
414 if (resid > uio->uio_resid)
415 VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
417 if (ioflag & IO_UNIT) {
418 (void)ffs_truncate(vp, osize, ioflag & IO_SYNC,
420 uio->uio_offset -= resid - uio->uio_resid;
421 uio->uio_resid = resid;
423 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
424 error = ffs_update(vp, 1);