freebsd-dev/sys/fs/fuse/fuse_io.c
Attilio Rao 89f6b8632c Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
  - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
  - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
  - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
  - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
    (in order to avoid visibility of implementation details)
  - The read-mode operations are added:
    VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
    VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
  sys/mutex.h in consumers directly to cater its inlining functions
  using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
  consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
  the compat layer because the name clash between FreeBSD and solaris
  versions must be avoided.
  At this purpose zfs redefines the vm_object locking functions
  directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit.  Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by:	EMC / Isilon storage division
Reviewed by:	jeff
Reviewed by:	pjd (ZFS specific review)
Discussed with:	alc
Tested by:	pho
2013-03-09 02:32:23 +00:00

811 lines
24 KiB
C

/*
* Copyright (c) 2007-2009 Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright (C) 2005 Csaba Henk.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/queue.h>
#include <sys/lock.h>
#include <sys/sx.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/unistd.h>
#include <sys/filedesc.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_object.h>
#include "fuse.h"
#include "fuse_file.h"
#include "fuse_node.h"
#include "fuse_internal.h"
#include "fuse_ipc.h"
#include "fuse_io.h"
#define FUSE_DEBUG_MODULE IO
#include "fuse_debug.h"
static int
fuse_read_directbackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh);
static int
fuse_read_biobackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh);
static int
fuse_write_directbackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh);
static int
fuse_write_biobackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh, int ioflag);
int
fuse_io_dispatch(struct vnode *vp, struct uio *uio, int ioflag,
struct ucred *cred)
{
struct fuse_filehandle *fufh;
int err, directio;
MPASS(vp->v_type == VREG || vp->v_type == VDIR);
err = fuse_filehandle_getrw(vp,
(uio->uio_rw == UIO_READ) ? FUFH_RDONLY : FUFH_WRONLY, &fufh);
if (err) {
printf("FUSE: io dispatch: filehandles are closed\n");
return err;
}
/*
* Ideally, when the daemon asks for direct io at open time, the
* standard file flag should be set according to this, so that would
* just change the default mode, which later on could be changed via
* fcntl(2).
* But this doesn't work, the O_DIRECT flag gets cleared at some point
* (don't know where). So to make any use of the Fuse direct_io option,
* we hardwire it into the file's private data (similarly to Linux,
* btw.).
*/
directio = (ioflag & IO_DIRECT) || !fsess_opt_datacache(vnode_mount(vp));
switch (uio->uio_rw) {
case UIO_READ:
if (directio) {
FS_DEBUG("direct read of vnode %ju via file handle %ju\n",
(uintmax_t)VTOILLU(vp), (uintmax_t)fufh->fh_id);
err = fuse_read_directbackend(vp, uio, cred, fufh);
} else {
FS_DEBUG("buffered read of vnode %ju\n",
(uintmax_t)VTOILLU(vp));
err = fuse_read_biobackend(vp, uio, cred, fufh);
}
break;
case UIO_WRITE:
if (directio) {
FS_DEBUG("direct write of vnode %ju via file handle %ju\n",
(uintmax_t)VTOILLU(vp), (uintmax_t)fufh->fh_id);
err = fuse_write_directbackend(vp, uio, cred, fufh);
} else {
FS_DEBUG("buffered write of vnode %ju\n",
(uintmax_t)VTOILLU(vp));
err = fuse_write_biobackend(vp, uio, cred, fufh, ioflag);
}
break;
default:
panic("uninterpreted mode passed to fuse_io_dispatch");
}
return (err);
}
static int
fuse_read_biobackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh)
{
struct buf *bp;
daddr_t lbn;
int bcount;
int err = 0, n = 0, on = 0;
off_t filesize;
const int biosize = fuse_iosize(vp);
FS_DEBUG("resid=%zx offset=%jx fsize=%jx\n",
uio->uio_resid, uio->uio_offset, VTOFUD(vp)->filesize);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
bcount = MIN(MAXBSIZE, biosize);
filesize = VTOFUD(vp)->filesize;
do {
if (fuse_isdeadfs(vp)) {
err = ENXIO;
break;
}
lbn = uio->uio_offset / biosize;
on = uio->uio_offset & (biosize - 1);
FS_DEBUG2G("biosize %d, lbn %d, on %d\n", biosize, (int)lbn, on);
/*
* Obtain the buffer cache block. Figure out the buffer size
* when we are at EOF. If we are modifying the size of the
* buffer based on an EOF condition we need to hold
* nfs_rslock() through obtaining the buffer to prevent
* a potential writer-appender from messing with n_size.
* Otherwise we may accidently truncate the buffer and
* lose dirty data.
*
* Note that bcount is *not* DEV_BSIZE aligned.
*/
if ((off_t)lbn * biosize >= filesize) {
bcount = 0;
} else if ((off_t)(lbn + 1) * biosize > filesize) {
bcount = filesize - (off_t)lbn *biosize;
}
bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
if (!bp)
return (EINTR);
/*
* If B_CACHE is not set, we must issue the read. If this
* fails, we return an error.
*/
if ((bp->b_flags & B_CACHE) == 0) {
bp->b_iocmd = BIO_READ;
vfs_busy_pages(bp, 0);
err = fuse_io_strategy(vp, bp);
if (err) {
brelse(bp);
return (err);
}
}
/*
* on is the offset into the current bp. Figure out how many
* bytes we can copy out of the bp. Note that bcount is
* NOT DEV_BSIZE aligned.
*
* Then figure out how many bytes we can copy into the uio.
*/
n = 0;
if (on < bcount)
n = MIN((unsigned)(bcount - on), uio->uio_resid);
if (n > 0) {
FS_DEBUG2G("feeding buffeater with %d bytes of buffer %p,"
" saying %d was asked for\n",
n, bp->b_data + on, n + (int)bp->b_resid);
err = uiomove(bp->b_data + on, n, uio);
}
brelse(bp);
FS_DEBUG2G("end of turn, err %d, uio->uio_resid %zd, n %d\n",
err, uio->uio_resid, n);
} while (err == 0 && uio->uio_resid > 0 && n > 0);
return (err);
}
static int
fuse_read_directbackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh)
{
struct fuse_dispatcher fdi;
struct fuse_read_in *fri;
int err = 0;
if (uio->uio_resid == 0)
return (0);
fdisp_init(&fdi, 0);
/*
* XXX In "normal" case we use an intermediate kernel buffer for
* transmitting data from daemon's context to ours. Eventually, we should
* get rid of this. Anyway, if the target uio lives in sysspace (we are
* called from pageops), and the input data doesn't need kernel-side
* processing (we are not called from readdir) we can already invoke
* an optimized, "peer-to-peer" I/O routine.
*/
while (uio->uio_resid > 0) {
fdi.iosize = sizeof(*fri);
fdisp_make_vp(&fdi, FUSE_READ, vp, uio->uio_td, cred);
fri = fdi.indata;
fri->fh = fufh->fh_id;
fri->offset = uio->uio_offset;
fri->size = MIN(uio->uio_resid,
fuse_get_mpdata(vp->v_mount)->max_read);
FS_DEBUG2G("fri->fh %ju, fri->offset %ju, fri->size %ju\n",
(uintmax_t)fri->fh, (uintmax_t)fri->offset,
(uintmax_t)fri->size);
if ((err = fdisp_wait_answ(&fdi)))
goto out;
FS_DEBUG2G("complete: got iosize=%d, requested fri.size=%zd; "
"resid=%zd offset=%ju\n",
fri->size, fdi.iosize, uio->uio_resid,
(uintmax_t)uio->uio_offset);
if ((err = uiomove(fdi.answ, MIN(fri->size, fdi.iosize), uio)))
break;
if (fdi.iosize < fri->size)
break;
}
out:
fdisp_destroy(&fdi);
return (err);
}
static int
fuse_write_directbackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh)
{
struct fuse_vnode_data *fvdat = VTOFUD(vp);
struct fuse_write_in *fwi;
struct fuse_dispatcher fdi;
size_t chunksize;
int diff;
int err = 0;
if (!uio->uio_resid)
return (0);
fdisp_init(&fdi, 0);
while (uio->uio_resid > 0) {
chunksize = MIN(uio->uio_resid,
fuse_get_mpdata(vp->v_mount)->max_write);
fdi.iosize = sizeof(*fwi) + chunksize;
fdisp_make_vp(&fdi, FUSE_WRITE, vp, uio->uio_td, cred);
fwi = fdi.indata;
fwi->fh = fufh->fh_id;
fwi->offset = uio->uio_offset;
fwi->size = chunksize;
if ((err = uiomove((char *)fdi.indata + sizeof(*fwi),
chunksize, uio)))
break;
if ((err = fdisp_wait_answ(&fdi)))
break;
diff = chunksize - ((struct fuse_write_out *)fdi.answ)->size;
if (diff < 0) {
err = EINVAL;
break;
}
uio->uio_resid += diff;
uio->uio_offset -= diff;
if (uio->uio_offset > fvdat->filesize)
fuse_vnode_setsize(vp, cred, uio->uio_offset);
}
fdisp_destroy(&fdi);
return (err);
}
static int
fuse_write_biobackend(struct vnode *vp, struct uio *uio,
struct ucred *cred, struct fuse_filehandle *fufh, int ioflag)
{
struct fuse_vnode_data *fvdat = VTOFUD(vp);
struct buf *bp;
daddr_t lbn;
int bcount;
int n, on, err = 0;
const int biosize = fuse_iosize(vp);
KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
FS_DEBUG("resid=%zx offset=%jx fsize=%jx\n",
uio->uio_resid, uio->uio_offset, fvdat->filesize);
if (vp->v_type != VREG)
return (EIO);
if (uio->uio_offset < 0)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
if (ioflag & IO_APPEND)
uio_setoffset(uio, fvdat->filesize);
/*
* Find all of this file's B_NEEDCOMMIT buffers. If our writes
* would exceed the local maximum per-file write commit size when
* combined with those, we must decide whether to flush,
* go synchronous, or return err. We don't bother checking
* IO_UNIT -- we just make all writes atomic anyway, as there's
* no point optimizing for something that really won't ever happen.
*/
do {
if (fuse_isdeadfs(vp)) {
err = ENXIO;
break;
}
lbn = uio->uio_offset / biosize;
on = uio->uio_offset & (biosize - 1);
n = MIN((unsigned)(biosize - on), uio->uio_resid);
FS_DEBUG2G("lbn %ju, on %d, n %d, uio offset %ju, uio resid %zd\n",
(uintmax_t)lbn, on, n,
(uintmax_t)uio->uio_offset, uio->uio_resid);
again:
/*
* Handle direct append and file extension cases, calculate
* unaligned buffer size.
*/
if (uio->uio_offset == fvdat->filesize && n) {
/*
* Get the buffer (in its pre-append state to maintain
* B_CACHE if it was previously set). Resize the
* nfsnode after we have locked the buffer to prevent
* readers from reading garbage.
*/
bcount = on;
FS_DEBUG("getting block from OS, bcount %d\n", bcount);
bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
if (bp != NULL) {
long save;
err = fuse_vnode_setsize(vp, cred,
uio->uio_offset + n);
if (err) {
brelse(bp);
break;
}
save = bp->b_flags & B_CACHE;
bcount += n;
allocbuf(bp, bcount);
bp->b_flags |= save;
}
} else {
/*
* Obtain the locked cache block first, and then
* adjust the file's size as appropriate.
*/
bcount = on + n;
if ((off_t)lbn * biosize + bcount < fvdat->filesize) {
if ((off_t)(lbn + 1) * biosize < fvdat->filesize)
bcount = biosize;
else
bcount = fvdat->filesize -
(off_t)lbn *biosize;
}
FS_DEBUG("getting block from OS, bcount %d\n", bcount);
bp = getblk(vp, lbn, bcount, PCATCH, 0, 0);
if (bp && uio->uio_offset + n > fvdat->filesize) {
err = fuse_vnode_setsize(vp, cred,
uio->uio_offset + n);
if (err) {
brelse(bp);
break;
}
}
}
if (!bp) {
err = EINTR;
break;
}
/*
* Issue a READ if B_CACHE is not set. In special-append
* mode, B_CACHE is based on the buffer prior to the write
* op and is typically set, avoiding the read. If a read
* is required in special append mode, the server will
* probably send us a short-read since we extended the file
* on our end, resulting in b_resid == 0 and, thusly,
* B_CACHE getting set.
*
* We can also avoid issuing the read if the write covers
* the entire buffer. We have to make sure the buffer state
* is reasonable in this case since we will not be initiating
* I/O. See the comments in kern/vfs_bio.c's getblk() for
* more information.
*
* B_CACHE may also be set due to the buffer being cached
* normally.
*/
if (on == 0 && n == bcount) {
bp->b_flags |= B_CACHE;
bp->b_flags &= ~B_INVAL;
bp->b_ioflags &= ~BIO_ERROR;
}
if ((bp->b_flags & B_CACHE) == 0) {
bp->b_iocmd = BIO_READ;
vfs_busy_pages(bp, 0);
fuse_io_strategy(vp, bp);
if ((err = bp->b_error)) {
brelse(bp);
break;
}
}
if (bp->b_wcred == NOCRED)
bp->b_wcred = crhold(cred);
/*
* If dirtyend exceeds file size, chop it down. This should
* not normally occur but there is an append race where it
* might occur XXX, so we log it.
*
* If the chopping creates a reverse-indexed or degenerate
* situation with dirtyoff/end, we 0 both of them.
*/
if (bp->b_dirtyend > bcount) {
FS_DEBUG("FUSE append race @%lx:%d\n",
(long)bp->b_blkno * biosize,
bp->b_dirtyend - bcount);
bp->b_dirtyend = bcount;
}
if (bp->b_dirtyoff >= bp->b_dirtyend)
bp->b_dirtyoff = bp->b_dirtyend = 0;
/*
* If the new write will leave a contiguous dirty
* area, just update the b_dirtyoff and b_dirtyend,
* otherwise force a write rpc of the old dirty area.
*
* While it is possible to merge discontiguous writes due to
* our having a B_CACHE buffer ( and thus valid read data
* for the hole), we don't because it could lead to
* significant cache coherency problems with multiple clients,
* especially if locking is implemented later on.
*
* as an optimization we could theoretically maintain
* a linked list of discontinuous areas, but we would still
* have to commit them separately so there isn't much
* advantage to it except perhaps a bit of asynchronization.
*/
if (bp->b_dirtyend > 0 &&
(on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
/*
* Yes, we mean it. Write out everything to "storage"
* immediatly, without hesitation. (Apart from other
* reasons: the only way to know if a write is valid
* if its actually written out.)
*/
bwrite(bp);
if (bp->b_error == EINTR) {
err = EINTR;
break;
}
goto again;
}
err = uiomove((char *)bp->b_data + on, n, uio);
/*
* Since this block is being modified, it must be written
* again and not just committed. Since write clustering does
* not work for the stage 1 data write, only the stage 2
* commit rpc, we have to clear B_CLUSTEROK as well.
*/
bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
if (err) {
bp->b_ioflags |= BIO_ERROR;
bp->b_error = err;
brelse(bp);
break;
}
/*
* Only update dirtyoff/dirtyend if not a degenerate
* condition.
*/
if (n) {
if (bp->b_dirtyend > 0) {
bp->b_dirtyoff = MIN(on, bp->b_dirtyoff);
bp->b_dirtyend = MAX((on + n), bp->b_dirtyend);
} else {
bp->b_dirtyoff = on;
bp->b_dirtyend = on + n;
}
vfs_bio_set_valid(bp, on, n);
}
err = bwrite(bp);
if (err)
break;
} while (uio->uio_resid > 0 && n > 0);
if (fuse_sync_resize && (fvdat->flag & FN_SIZECHANGE) != 0)
fuse_vnode_savesize(vp, cred);
return (err);
}
int
fuse_io_strategy(struct vnode *vp, struct buf *bp)
{
struct fuse_filehandle *fufh;
struct fuse_vnode_data *fvdat = VTOFUD(vp);
struct ucred *cred;
struct uio *uiop;
struct uio uio;
struct iovec io;
int error = 0;
const int biosize = fuse_iosize(vp);
MPASS(vp->v_type == VREG || vp->v_type == VDIR);
MPASS(bp->b_iocmd == BIO_READ || bp->b_iocmd == BIO_WRITE);
FS_DEBUG("inode=%ju offset=%jd resid=%ld\n",
(uintmax_t)VTOI(vp), (intmax_t)(((off_t)bp->b_blkno) * biosize),
bp->b_bcount);
error = fuse_filehandle_getrw(vp,
(bp->b_iocmd == BIO_READ) ? FUFH_RDONLY : FUFH_WRONLY, &fufh);
if (error) {
printf("FUSE: strategy: filehandles are closed\n");
bp->b_ioflags |= BIO_ERROR;
bp->b_error = error;
return (error);
}
cred = bp->b_iocmd == BIO_READ ? bp->b_rcred : bp->b_wcred;
uiop = &uio;
uiop->uio_iov = &io;
uiop->uio_iovcnt = 1;
uiop->uio_segflg = UIO_SYSSPACE;
uiop->uio_td = curthread;
/*
* clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
* do this here so we do not have to do it in all the code that
* calls us.
*/
bp->b_flags &= ~B_INVAL;
bp->b_ioflags &= ~BIO_ERROR;
KASSERT(!(bp->b_flags & B_DONE),
("fuse_io_strategy: bp %p already marked done", bp));
if (bp->b_iocmd == BIO_READ) {
io.iov_len = uiop->uio_resid = bp->b_bcount;
io.iov_base = bp->b_data;
uiop->uio_rw = UIO_READ;
uiop->uio_offset = ((off_t)bp->b_blkno) * biosize;
error = fuse_read_directbackend(vp, uiop, cred, fufh);
if ((!error && uiop->uio_resid) ||
(fsess_opt_brokenio(vnode_mount(vp)) && error == EIO &&
uiop->uio_offset < fvdat->filesize && fvdat->filesize > 0 &&
uiop->uio_offset >= fvdat->cached_attrs.va_size)) {
/*
* If we had a short read with no error, we must have
* hit a file hole. We should zero-fill the remainder.
* This can also occur if the server hits the file EOF.
*
* Holes used to be able to occur due to pending
* writes, but that is not possible any longer.
*/
int nread = bp->b_bcount - uiop->uio_resid;
int left = uiop->uio_resid;
if (error != 0) {
printf("FUSE: Fix broken io: offset %ju, "
" resid %zd, file size %ju/%ju\n",
(uintmax_t)uiop->uio_offset,
uiop->uio_resid, fvdat->filesize,
fvdat->cached_attrs.va_size);
error = 0;
}
if (left > 0)
bzero((char *)bp->b_data + nread, left);
uiop->uio_resid = 0;
}
if (error) {
bp->b_ioflags |= BIO_ERROR;
bp->b_error = error;
}
} else {
/*
* If we only need to commit, try to commit
*/
if (bp->b_flags & B_NEEDCOMMIT) {
FS_DEBUG("write: B_NEEDCOMMIT flags set\n");
}
/*
* Setup for actual write
*/
if ((off_t)bp->b_blkno * biosize + bp->b_dirtyend >
fvdat->filesize)
bp->b_dirtyend = fvdat->filesize -
(off_t)bp->b_blkno * biosize;
if (bp->b_dirtyend > bp->b_dirtyoff) {
io.iov_len = uiop->uio_resid = bp->b_dirtyend
- bp->b_dirtyoff;
uiop->uio_offset = (off_t)bp->b_blkno * biosize
+ bp->b_dirtyoff;
io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
uiop->uio_rw = UIO_WRITE;
error = fuse_write_directbackend(vp, uiop, cred, fufh);
if (error == EINTR || error == ETIMEDOUT
|| (!error && (bp->b_flags & B_NEEDCOMMIT))) {
bp->b_flags &= ~(B_INVAL | B_NOCACHE);
if ((bp->b_flags & B_PAGING) == 0) {
bdirty(bp);
bp->b_flags &= ~B_DONE;
}
if ((error == EINTR || error == ETIMEDOUT) &&
(bp->b_flags & B_ASYNC) == 0)
bp->b_flags |= B_EINTR;
} else {
if (error) {
bp->b_ioflags |= BIO_ERROR;
bp->b_flags |= B_INVAL;
bp->b_error = error;
}
bp->b_dirtyoff = bp->b_dirtyend = 0;
}
} else {
bp->b_resid = 0;
bufdone(bp);
return (0);
}
}
bp->b_resid = uiop->uio_resid;
bufdone(bp);
return (error);
}
int
fuse_io_flushbuf(struct vnode *vp, int waitfor, struct thread *td)
{
struct vop_fsync_args a = {
.a_vp = vp,
.a_waitfor = waitfor,
.a_td = td,
};
return (vop_stdfsync(&a));
}
/*
* Flush and invalidate all dirty buffers. If another process is already
* doing the flush, just wait for completion.
*/
int
fuse_io_invalbuf(struct vnode *vp, struct thread *td)
{
struct fuse_vnode_data *fvdat = VTOFUD(vp);
int error = 0;
if (vp->v_iflag & VI_DOOMED)
return 0;
ASSERT_VOP_ELOCKED(vp, "fuse_io_invalbuf");
while (fvdat->flag & FN_FLUSHINPROG) {
struct proc *p = td->td_proc;
if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF)
return EIO;
fvdat->flag |= FN_FLUSHWANT;
tsleep(&fvdat->flag, PRIBIO + 2, "fusevinv", 2 * hz);
error = 0;
if (p != NULL) {
PROC_LOCK(p);
if (SIGNOTEMPTY(p->p_siglist) ||
SIGNOTEMPTY(td->td_siglist))
error = EINTR;
PROC_UNLOCK(p);
}
if (error == EINTR)
return EINTR;
}
fvdat->flag |= FN_FLUSHINPROG;
if (vp->v_bufobj.bo_object != NULL) {
VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
}
error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
while (error) {
if (error == ERESTART || error == EINTR) {
fvdat->flag &= ~FN_FLUSHINPROG;
if (fvdat->flag & FN_FLUSHWANT) {
fvdat->flag &= ~FN_FLUSHWANT;
wakeup(&fvdat->flag);
}
return EINTR;
}
error = vinvalbuf(vp, V_SAVE, PCATCH, 0);
}
fvdat->flag &= ~FN_FLUSHINPROG;
if (fvdat->flag & FN_FLUSHWANT) {
fvdat->flag &= ~FN_FLUSHWANT;
wakeup(&fvdat->flag);
}
return (error);
}