2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2000-2003 Tor Egge
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/fcntl.h>
38 #include <sys/limits.h>
39 #include <sys/mount.h>
40 #include <sys/namei.h>
41 #include <sys/vnode.h>
43 #include <sys/filio.h>
44 #include <sys/ttycom.h>
47 #include <sys/rwlock.h>
48 #include <ufs/ufs/extattr.h>
49 #include <ufs/ufs/quota.h>
50 #include <ufs/ufs/inode.h>
51 #include <ufs/ufs/ufsmount.h>
52 #include <ufs/ufs/ufs_extern.h>
53 #include <ufs/ffs/fs.h>
54 #include <ufs/ffs/ffs_extern.h>
57 #include <vm/vm_extern.h>
58 #include <vm/vm_object.h>
59 #include <sys/kernel.h>
60 #include <sys/sysctl.h>
62 static int ffs_rawread_readahead(struct vnode *vp,
68 static int ffs_rawread_main(struct vnode *vp,
71 static int ffs_rawread_sync(struct vnode *vp);
73 int ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone);
75 SYSCTL_DECL(_vfs_ffs);
77 static int ffsrawbufcnt = 4;
78 SYSCTL_INT(_vfs_ffs, OID_AUTO, ffsrawbufcnt, CTLFLAG_RD, &ffsrawbufcnt, 0,
79 "Buffers available for raw reads");
81 static int allowrawread = 1;
82 SYSCTL_INT(_vfs_ffs, OID_AUTO, allowrawread, CTLFLAG_RW, &allowrawread, 0,
83 "Flag to enable raw reads");
85 static int rawreadahead = 1;
86 SYSCTL_INT(_vfs_ffs, OID_AUTO, rawreadahead, CTLFLAG_RW, &rawreadahead, 0,
87 "Flag to enable readahead for long raw reads");
90 ffs_rawread_setup(void *arg __unused)
93 ffsrawbufcnt = (nswbuf > 100 ) ? (nswbuf - (nswbuf >> 4)) : nswbuf - 8;
95 SYSINIT(ffs_raw, SI_SUB_VM_CONF, SI_ORDER_ANY, ffs_rawread_setup, NULL);
98 ffs_rawread_sync(struct vnode *vp)
106 /* Check for dirty mmap, pending writes and dirty buffers */
110 if (bo->bo_numoutput > 0 ||
111 bo->bo_dirty.bv_cnt > 0 ||
112 ((obj = vp->v_object) != NULL &&
113 (obj->flags & OBJ_MIGHTBEDIRTY) != 0)) {
117 if (vn_start_write(vp, &mp, V_NOWAIT) != 0) {
118 if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE)
123 (void) vn_start_write(vp, &mp, V_WAIT);
124 VOP_LOCK(vp, LK_EXCLUSIVE);
125 } else if (VOP_ISLOCKED(vp) != LK_EXCLUSIVE) {
127 /* Upgrade to exclusive lock, this might block */
128 VOP_LOCK(vp, LK_UPGRADE);
134 /* Check if vnode was reclaimed while unlocked. */
135 if ((vp->v_iflag & VI_DOOMED) != 0) {
138 VOP_LOCK(vp, LK_DOWNGRADE);
139 vn_finished_write(mp);
142 /* Attempt to msync mmap() regions to clean dirty mmap */
143 if ((obj = vp->v_object) != NULL &&
144 (obj->flags & OBJ_MIGHTBEDIRTY) != 0) {
146 VM_OBJECT_WLOCK(obj);
147 vm_object_page_clean(obj, 0, 0, OBJPC_SYNC);
148 VM_OBJECT_WUNLOCK(obj);
152 /* Wait for pending writes to complete */
154 error = bufobj_wwait(&vp->v_bufobj, 0, 0);
156 /* XXX: can't happen with a zero timeout ??? */
159 VOP_LOCK(vp, LK_DOWNGRADE);
160 vn_finished_write(mp);
163 /* Flush dirty buffers */
164 if (bo->bo_dirty.bv_cnt > 0) {
166 if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0) {
168 VOP_LOCK(vp, LK_DOWNGRADE);
169 vn_finished_write(mp);
173 if (bo->bo_numoutput > 0 || bo->bo_dirty.bv_cnt > 0)
174 panic("ffs_rawread_sync: dirty bufs");
178 VOP_LOCK(vp, LK_DOWNGRADE);
179 vn_finished_write(mp);
189 ffs_rawread_readahead(struct vnode *vp,
206 bsize = vp->v_mount->mnt_stat.f_iosize;
211 iolen = ((vm_offset_t) udata) & PAGE_MASK;
213 if (bp->b_bcount + iolen > bp->b_kvasize) {
214 bp->b_bcount = bp->b_kvasize;
216 bp->b_bcount -= PAGE_SIZE;
218 bp->b_flags = 0; /* XXX necessary ? */
219 bp->b_iocmd = BIO_READ;
220 bp->b_iodone = bdone;
222 blockno = offset / bsize;
223 blockoff = (offset % bsize) / DEV_BSIZE;
224 if ((daddr_t) blockno != blockno) {
225 return EINVAL; /* blockno overflow */
228 bp->b_lblkno = bp->b_blkno = blockno;
230 error = ufs_bmaparray(vp, bp->b_lblkno, &blkno, NULL, &bforwards, NULL);
235 /* Fill holes with NULs to preserve semantics */
237 if (bp->b_bcount + blockoff * DEV_BSIZE > bsize)
238 bp->b_bcount = bsize - blockoff * DEV_BSIZE;
239 bp->b_bufsize = bp->b_bcount;
241 if (vmapbuf(bp, 1) < 0)
245 bzero(bp->b_data, bp->b_bufsize);
247 /* Mark operation completed (similar to bufdone()) */
250 bp->b_flags |= B_DONE;
253 bp->b_blkno = blkno + blockoff;
254 bp->b_offset = bp->b_iooffset = (blkno + blockoff) * DEV_BSIZE;
256 if (bp->b_bcount + blockoff * DEV_BSIZE > bsize * (1 + bforwards))
257 bp->b_bcount = bsize * (1 + bforwards) - blockoff * DEV_BSIZE;
258 bp->b_bufsize = bp->b_bcount;
260 if (vmapbuf(bp, 1) < 0)
263 BO_STRATEGY(&dp->v_bufobj, bp);
269 ffs_rawread_main(struct vnode *vp,
273 struct buf *bp, *nbp, *tbp;
280 td = uio->uio_td ? uio->uio_td : curthread;
281 udata = uio->uio_iov->iov_base;
282 resid = uio->uio_resid;
283 offset = uio->uio_offset;
286 * keep the process from being swapped
298 if (bp == NULL) { /* Setup first read */
299 /* XXX: Leave some bufs for swap */
300 bp = getpbuf(&ffsrawbufcnt);
302 error = ffs_rawread_readahead(vp, udata, offset,
307 if (resid > bp->b_bufsize) { /* Setup fist readahead */
308 /* XXX: Leave bufs for swap */
309 if (rawreadahead != 0)
310 nbp = trypbuf(&ffsrawbufcnt);
316 nerror = ffs_rawread_readahead(vp,
327 relpbuf(nbp, &ffsrawbufcnt);
334 bwait(bp, PRIBIO, "rawrd");
337 iolen = bp->b_bcount - bp->b_resid;
338 if (iolen == 0 && (bp->b_ioflags & BIO_ERROR) == 0) {
339 nerror = 0; /* Ignore possible beyond EOF error */
343 if ((bp->b_ioflags & BIO_ERROR) != 0) {
350 if (iolen < bp->b_bufsize) {
351 /* Incomplete read. Try to read remaining part */
352 error = ffs_rawread_readahead(vp,
355 bp->b_bufsize - iolen,
360 } else if (nbp != NULL) { /* Complete read with readahead */
366 if (resid <= bp->b_bufsize) { /* No more readaheads */
368 relpbuf(nbp, &ffsrawbufcnt);
370 } else { /* Setup next readahead */
371 nerror = ffs_rawread_readahead(vp,
382 relpbuf(nbp, &ffsrawbufcnt);
386 } else if (nerror != 0) {/* Deferred Readahead error */
388 } else if (resid > 0) { /* More to read, no readahead */
389 error = ffs_rawread_readahead(vp, udata, offset,
398 relpbuf(bp, &ffsrawbufcnt);
400 if (nbp != NULL) { /* Run down readahead buffer */
401 bwait(nbp, PRIBIO, "rawrd");
404 relpbuf(nbp, &ffsrawbufcnt);
410 uio->uio_iov->iov_base = udata;
411 uio->uio_resid = resid;
412 uio->uio_offset = offset;
418 ffs_rawread(struct vnode *vp,
422 if (allowrawread != 0 &&
423 uio->uio_iovcnt == 1 &&
424 uio->uio_segflg == UIO_USERSPACE &&
425 uio->uio_resid == uio->uio_iov->iov_len &&
426 (((uio->uio_td != NULL) ? uio->uio_td : curthread)->td_pflags &
427 TDP_DEADLKTREAT) == 0) {
428 int secsize; /* Media sector size */
429 off_t filebytes; /* Bytes left of file */
430 int blockbytes; /* Bytes left of file in full blocks */
431 int partialbytes; /* Bytes in last partial block */
432 int skipbytes; /* Bytes not to read in ffs_rawread */
437 /* Only handle sector aligned reads */
439 secsize = ITODEVVP(ip)->v_bufobj.bo_bsize;
440 if ((uio->uio_offset & (secsize - 1)) == 0 &&
441 (uio->uio_resid & (secsize - 1)) == 0) {
443 /* Sync dirty pages and buffers if needed */
444 error = ffs_rawread_sync(vp);
448 /* Check for end of file */
449 if (ip->i_size > uio->uio_offset) {
450 filebytes = ip->i_size - uio->uio_offset;
452 /* No special eof handling needed ? */
453 if (uio->uio_resid <= filebytes) {
455 return ffs_rawread_main(vp, uio);
458 partialbytes = ((unsigned int) ip->i_size) %
460 blockbytes = (int) filebytes - partialbytes;
461 if (blockbytes > 0) {
462 skipbytes = uio->uio_resid -
464 uio->uio_resid = blockbytes;
465 error = ffs_rawread_main(vp, uio);
466 uio->uio_resid += skipbytes;
469 /* Read remaining part using buffer */