File: [Development] / xfs-linux / xfs_rw.c (download)
Revision 1.29, Fri Apr 15 15:03:53 1994 UTC (23 years, 6 months ago) by tap
Branch: MAIN
Changes since 1.28: +1 -0
lines
add "sys/uuid.h" include file
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#include <sys/types.h>
#ifdef SIM
#define _KERNEL 1
#endif
#include <sys/buf.h>
#include <sys/uio.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/cred.h>
#include <sys/sysmacros.h>
#include <sys/pfdat.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/uuid.h>
#include <sys/grio.h>
#ifdef SIM
#undef _KERNEL
#endif
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
#include <sys/var.h>
#ifdef SIM
#include <bstring.h>
#include <stdio.h>
#else
#include <sys/conf.h>
#include <sys/systm.h>
#endif
#include <sys/kmem.h>
#include <sys/sema.h>
#include <sys/uuid.h>
#include <sys/param.h>
#include <sys/file.h>
#include <sys/region.h>
#include <sys/runq.h>
#include <sys/schedctl.h>
#include "xfs_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc.h"
#include "xfs_ag.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode_item.h"
#include "xfs_inode.h"
#ifdef SIM
#include "sim.h"
#endif
/*
* This lock is used by xfs_strat_write().
* The xfs_strat_lock is initialized in xfs_init().
*/
lock_t xfs_strat_lock;
/*
* Variables for coordination with the xfsd daemons.
* The xfsd_lock and xfsd_wait variables are initialized
* in xfs_init();
*/
static int xfsd_count;
static buf_t *xfsd_list;
static int xfsd_bufcount;
lock_t xfsd_lock;
sema_t xfsd_wait;
STATIC void
xfs_zero_bp(buf_t *bp,
int data_offset,
int data_len);
STATIC int
xfs_retrieved(int available,
off_t offset,
int count,
uint *total_retrieved,
__int64_t isize);
int
xfs_diordwr(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp,
int rw);
extern int
xfs_grio_req(xfs_inode_t *,
struct reservation_id *,
uio_t *,
int,
cred_t *,
int);
/*
* Round the given file offset down to the nearest read/write
* size boundary.
*/
#define XFS_READIO_ALIGN(mp,off) (((off) >> mp->m_readio_log) \
<< mp->m_readio_log)
#define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \
<< mp->m_writeio_log)
/*
* Fill in the bmap structure to indicate how the next bp
* should fit over the given extent.
*
* Everything here is in terms of file system blocks, not BBs.
*/
void
xfs_next_bmap(xfs_mount_t *mp,
xfs_bmbt_irec_t *imapp,
struct bmapval *bmapp,
int iosize,
xfs_fileoff_t ioalign,
xfs_fileoff_t last_offset,
xfs_fileoff_t req_offset)
{
int extra_blocks;
xfs_fileoff_t size_diff;
xfs_fileoff_t ext_offset;
xfs_fsblock_t start_block;
/*
* Make sure that the request offset lies in the extent given.
*/
ASSERT(req_offset >= imapp->br_startoff);
ASSERT(req_offset < (imapp->br_startoff + imapp->br_blockcount));
if (last_offset == -1) {
ASSERT(ioalign != -1);
if (ioalign < imapp->br_startoff) {
/*
* The alignment we guessed at can't
* happen on this extent, so align
* to the beginning of this extent.
* Subtract whatever we drop from the
* iosize so that we stay aligned on
* our iosize boundaries.
*/
size_diff = imapp->br_startoff - ioalign;
iosize -= size_diff;
ASSERT(iosize > 0);
ext_offset = 0;
bmapp->offset = imapp->br_startoff;
ASSERT(bmapp->offset <= req_offset);
} else {
/*
* The alignment requested fits on this
* extent, so use it.
*/
ext_offset = ioalign - imapp->br_startoff;
bmapp->offset = ioalign;
ASSERT(bmapp->offset <= req_offset);
}
} else {
/*
* This is one of a series of sequential access to the
* file. Make sure to line up the buffer we specify
* so that it doesn't overlap the last one. It should
* either be the same as the last one (if we need data
* from it) or follow immediately after the last one.
*/
ASSERT(ioalign == -1);
if (last_offset >= imapp->br_startoff) {
/*
* The last I/O was from the same extent
* that this one will at least start on.
* This assumes that we're going sequentially.
*/
if (req_offset < (last_offset + iosize)) {
/*
* This request overlaps the buffer
* we used for the last request. Just
* get that buffer again.
*/
ext_offset = last_offset -
imapp->br_startoff;
bmapp->offset = last_offset;
} else {
/*
* This request does not overlap the buffer
* used for the last one. Get it its own.
*/
ext_offset = req_offset - imapp->br_startoff;
bmapp->offset = req_offset;
}
} else {
/*
* The last I/O was on a different extent than
* this one. We start at the beginning of this one.
* This assumes that we're going sequentially.
*/
ext_offset = 0;
bmapp->offset = req_offset;
ASSERT(bmapp->offset == imapp->br_startoff);
}
}
start_block = imapp->br_startblock;
if (start_block == HOLESTARTBLOCK) {
bmapp->bn = -1;
bmapp->eof = BMAP_HOLE;
} else if (start_block == DELAYSTARTBLOCK) {
bmapp->bn = -1;
bmapp->eof = BMAP_DELAY;
} else {
bmapp->bn = start_block + ext_offset;
bmapp->eof = 0;
}
bmapp->length = iosize;
/*
* If the iosize from our offset extends beyond the
* end of the extent, then trim down the length
* to match that of the extent.
*/
extra_blocks = (bmapp->offset + bmapp->length) -
(imapp->br_startoff + imapp->br_blockcount);
if (extra_blocks > 0) {
bmapp->length -= extra_blocks;
ASSERT(bmapp->length > 0);
}
bmapp->bsize = xfs_fsb_to_b(mp, bmapp->length);
}
/*
* xfs_retrieved() is a utility function used to calculate the
* value of bmap.pbsize.
*
* Available is the number of bytes mapped by the current bmap.
* Offset is the file offset of the current request by the user.
* Count is the size of the current request by the user.
* Total_retrieved is a running total of the number of bytes
* which have been setup for the user in this call so far.
* Isize is the current size of the file being read.
*/
STATIC int
xfs_retrieved(int available,
off_t offset,
int count,
uint *total_retrieved,
__int64_t isize)
{
int retrieved;
__int64_t file_bytes_left;
if ((available + *total_retrieved) > count) {
/*
* This buffer will return more bytes
* than we asked for. Trim retrieved
* so we can set bmapp->pbsize correctly.
*/
retrieved = count - *total_retrieved;
} else {
retrieved = available;
}
file_bytes_left = isize - (offset + *total_retrieved);
if (file_bytes_left < retrieved) {
/*
* The user has requested more bytes
* than there are in the file. Trim
* down the number to those left in
* the file.
*/
retrieved = file_bytes_left;
}
*total_retrieved += retrieved;
return retrieved;
}
/*
* xfs_iomap_extra()
*
* This is called to fill in the bmapval for a page which is beyond
* the end of the file. We map the entire fs block that the page
* resides on here. That is because all XFS buffers should be a
* multiple of the fs block size. If the fs block size is less than
* the size of a page, then map all of the fs blocks in the given
* range. We may get partial pages here if the fs block size is less
* than the page size and this page overlaps the EOF. The first part
* of the page would have been handled in the normal path, and the
* rest of the page is passed off to here.
*/
STATIC void
xfs_iomap_extra(xfs_inode_t *ip,
off_t offset,
size_t count,
struct bmapval *bmapp,
int *nbmaps)
{
xfs_fileoff_t offset_fsb;
xfs_fileoff_t count_fsb;
xfs_mount_t *mp;
ASSERT(((dpoff(offset) == 0) && (count == NBPP)) ||
((offset == ip->i_d.di_size) && (count < NBPP)));
ASSERT(offset >= ip->i_d.di_size);
mp = ip->i_mount;
offset_fsb = xfs_b_to_fsbt(mp, offset);
count_fsb = xfs_b_to_fsb(mp, count);
/*
* We set BMAP_DELAY rather than BMAP_HOLE in the bmap
* to be consistent with what the write code is doing for
* these extra pages.
*/
*nbmaps = 1;
bmapp->eof = BMAP_DELAY | BMAP_EOF;
bmapp->bn = -1;
bmapp->offset = xfs_fsb_to_bb(mp, offset_fsb);
bmapp->length = xfs_fsb_to_bb(mp, count_fsb);
bmapp->bsize = xfs_fsb_to_b(mp, count_fsb);
bmapp->pboff = offset - xfs_fsb_to_b(mp, offset_fsb);
bmapp->pbsize = count;
if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
bmapp->pbdev = mp->m_rtdev;
} else {
bmapp->pbdev = mp->m_dev;
}
}
void
xfs_iomap_read(xfs_inode_t *ip,
off_t offset,
size_t count,
struct bmapval *bmapp,
int *nbmaps)
{
xfs_fileoff_t offset_fsb;
xfs_fileoff_t ioalign;
xfs_fileoff_t last_offset;
xfs_fileoff_t last_required_offset;
xfs_fileoff_t last_fsb;
xfs_fileoff_t next_offset;
__int64_t nisize;
off_t offset_page;
int nimaps;
unsigned int iosize;
unsigned int retrieved_bytes;
unsigned int total_retrieved_bytes;
short filled_bmaps;
short read_aheads;
int x;
xfs_mount_t *mp;
struct bmapval *curr_bmapp;
struct bmapval *next_bmapp;
struct bmapval *last_bmapp;
struct bmapval *first_read_ahead_bmapp;
struct bmapval *next_read_ahead_bmapp;
xfs_bmbt_irec_t *curr_imapp;
xfs_bmbt_irec_t *last_imapp;
#define XFS_READ_IMAPS XFS_BMAP_MAX_NMAP
xfs_bmbt_irec_t imap[XFS_READ_IMAPS];
mp = ip->i_mount;
nisize = ip->i_new_size;
if (nisize < ip->i_d.di_size) {
nisize = ip->i_d.di_size;
}
offset_fsb = xfs_b_to_fsbt(mp, offset);
nimaps = XFS_READ_IMAPS;
last_fsb = xfs_b_to_fsb(mp, nisize);
if (last_fsb <= offset_fsb) {
/*
* One of the pages beyond the EOF created by the
* write code is being pushed out by the VM system.
* Handle it here so it does not interfere with the
* normal path code. If the fs block size is less
* than the page size then this may even be only a
* part of a page.
*/
xfs_iomap_extra(ip, offset, count, bmapp, nbmaps);
return;
}
(void)xfs_bmapi(NULL, ip, offset_fsb,
(xfs_extlen_t)(last_fsb - offset_fsb),
XFS_BMAPI_ENTIRE, NULLFSBLOCK, 0, imap,
&nimaps, NULL);
if ((offset == ip->i_next_offset) &&
(count <= ip->i_last_req_sz)) {
/*
* Sequential I/O of same size as last time.
*/
ASSERT(ip->i_io_size > 0);
iosize = ip->i_io_size;
last_offset = ip->i_io_offset;
ioalign = -1;
} else {
/*
* The I/O size for the file has not yet been
* determined, so figure it out.
*/
if (xfs_b_to_fsb(mp, count) <= mp->m_readio_blocks) {
/*
* The request is smaller than our
* minimum I/O size, so default to
* the minimum. For these size requests
* we always want to align the requests
* to XFS_READ_SIZE boundaries as well.
*/
iosize = mp->m_readio_blocks;
ioalign = XFS_READIO_ALIGN(mp, offset);
ioalign = xfs_b_to_fsbt(mp, ioalign);
} else {
/*
* The request is bigger than our
* minimum I/O size and it's the
* first one in this sequence, so
* set the I/O size for the file
* now.
*
* In calculating the offset rounded down
* to a page, make sure to round down the
* fs block offset rather than the byte
* offset for the case where our block size
* is greater than the page size. This way
* offset_page will always align to a fs block
* as well as a page.
*
* For the end of the I/O we need to round
* offset + count up to a page boundary and
* then round that up to a file system block
* boundary.
*/
offset_page = ctob(btoct(xfs_fsb_to_b(mp, offset_fsb)));
last_fsb = xfs_b_to_fsb(mp,
ctob(btoc(offset + count)));
iosize = last_fsb - xfs_b_to_fsbt(mp, offset_page);
ioalign = xfs_b_to_fsb(mp, offset_page);
}
last_offset = -1;
}
/*
* Now we've got the I/O size and the last offset,
* so start figuring out how to align our
* buffers.
*/
xfs_next_bmap(mp, imap, bmapp, iosize, ioalign,
last_offset, offset_fsb);
ASSERT((bmapp->length > 0) &&
(offset >= xfs_fsb_to_b(mp, bmapp->offset)));
if ((nimaps == 1) &&
(xfs_fsb_to_b(mp, bmapp->offset + bmapp->length) >= nisize)) {
bmapp->eof |= BMAP_EOF;
}
bmapp->pboff = offset - xfs_fsb_to_b(mp, bmapp->offset);
retrieved_bytes = bmapp->bsize - bmapp->pboff;
total_retrieved_bytes = 0;
bmapp->pbsize = xfs_retrieved(retrieved_bytes, offset, count,
&total_retrieved_bytes, nisize);
/*
* Only map additional buffers if they've been asked for
* and the I/O being done is sequential and has reached the
* point where we need to initiate more read ahead or we didn't get
* the whole request in the first bmap.
*/
filled_bmaps = 1;
last_required_offset = bmapp[0].offset;
first_read_ahead_bmapp = NULL;
if ((*nbmaps > 1) &&
(((offset == ip->i_next_offset) &&
(offset_fsb >= ip->i_reada_blkno)) ||
(retrieved_bytes < count))) {
curr_bmapp = &bmapp[0];
next_bmapp = &bmapp[1];
last_bmapp = &bmapp[*nbmaps - 1];
curr_imapp = &imap[0];
last_imapp = &imap[nimaps - 1];
/*
* curr_bmap is always the last one we filled
* in, and next_bmapp is always the next one
* to be filled in.
*/
while (next_bmapp <= last_bmapp) {
next_offset = curr_bmapp->offset +
curr_bmapp->length;
if (next_offset <
(curr_imapp->br_startoff +
curr_imapp->br_blockcount)) {
xfs_next_bmap(mp, curr_imapp,
next_bmapp, iosize, -1,
curr_bmapp->offset,
next_offset);
} else {
curr_imapp++;
if (curr_imapp <= last_imapp) {
xfs_next_bmap(mp,
curr_imapp, next_bmapp,
iosize, -1,
curr_bmapp->offset,
next_offset);
} else {
/*
* We're out of imaps. We
* either hit the end of
* file or just didn't give
* enough of them to bmapi.
* The caller will just come
* back if we haven't done
* enough yet.
*/
break;
}
}
filled_bmaps++;
curr_bmapp = next_bmapp;
next_bmapp++;
/*
* Make sure to fill in the pboff and pbsize
* fields as long as the bmaps are required for
* the request (as opposed to strictly read-ahead).
*/
if (total_retrieved_bytes < count) {
curr_bmapp->pboff = 0;
curr_bmapp->pbsize =
xfs_retrieved(curr_bmapp->bsize,
offset, count,
&total_retrieved_bytes,
nisize);
}
if ((curr_imapp == last_imapp) &&
(xfs_fsb_to_b(mp, curr_bmapp->offset +
curr_bmapp->length) >= nisize)) {
curr_bmapp->eof |= BMAP_EOF;
}
/*
* Keep track of the offset of the last buffer
* needed to satisfy the I/O request. This will
* be used for i_io_offset later. Also record
* the first bmapp used to track a read ahead.
*/
if (xfs_fsb_to_b(mp, curr_bmapp->offset) <
(offset + count)) {
last_required_offset = curr_bmapp->offset;
} else if (first_read_ahead_bmapp == NULL) {
first_read_ahead_bmapp = curr_bmapp;
}
}
/*
* If we're describing any read-ahead here, then move
* the read-ahead blkno up to the point where we've
* gone through half the read-ahead described here.
* This way we don't issue more read-ahead until we
* are half-way through the last read-ahead.
*
* If we're not describing any read-ahead because the
* request is just fragmented, then move up the
* read-ahead blkno to just past what we're returning
* so that we can maybe start it on the next request.
*/
if (first_read_ahead_bmapp != NULL) {
read_aheads = curr_bmapp - first_read_ahead_bmapp +1;
next_read_ahead_bmapp = first_read_ahead_bmapp +
(read_aheads / 2);
ip->i_reada_blkno = next_read_ahead_bmapp->offset;
} else {
ip->i_reada_blkno = curr_bmapp->offset +
curr_bmapp->length;
}
} else if ((*nbmaps > 1) && (offset != ip->i_io_offset)) {
/*
* In this case the caller is not yet accessing the
* file sequentially, but set the read-ahead blkno
* so that we can tell if they start doing so.
*/
ip->i_reada_blkno = bmapp[0].offset + bmapp[0].length;
}
ip->i_io_size = iosize;
ip->i_io_offset = last_required_offset;
if (count > ip->i_last_req_sz) {
/*
* Record the "last request size" for the file.
* We don't let it shrink so that big requests
* that are not satisfied in one call here still
* record the full request size (not the smaller
* one that comes in to finish mapping the request).
*/
ip->i_last_req_sz = count;
}
if (total_retrieved_bytes >= count) {
/*
* We've mapped all of the caller's request, so
* the next request in a sequential read will
* come in the block this one ended on or the
* next if we consumed up to the very end of
* a block.
*/
ip->i_next_offset = offset + count;
} else {
/*
* We didn't satisfy the entire request, so we
* can expect xfs_read_file() to come back with
* what is left of the request.
*/
ip->i_next_offset = offset + total_retrieved_bytes;
}
*nbmaps = filled_bmaps;
for (x = 0; x < filled_bmaps; x++) {
curr_bmapp = &bmapp[x];
if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
curr_bmapp->pbdev = mp->m_rtdev;
} else {
curr_bmapp->pbdev = mp->m_dev;
}
curr_bmapp->offset = xfs_fsb_to_bb(mp, curr_bmapp->offset);
curr_bmapp->length = xfs_fsb_to_bb(mp, curr_bmapp->length);
if (curr_bmapp->bn != -1) {
curr_bmapp->bn =
xfs_fsb_to_daddr(mp, curr_bmapp->bn);
}
}
return;
}
int
xfs_read_file(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp)
{
#define XFS_READ_BMAPS 4
struct bmapval bmaps[XFS_READ_BMAPS];
struct bmapval *bmapp;
int nbmaps;
buf_t *bp;
int read_bmaps;
int buffer_bytes_ok;
xfs_inode_t *ip;
int error;
ip = XFS_VTOI(vp);
error = 0;
buffer_bytes_ok = 0;
/*
* Loop until uio->uio_resid, which is the number of bytes the
* caller has requested, goes to 0 or we get an error. Each
* call to xfs_iomap_read tries to map as much of the request
* plus read-ahead as it can.
*/
do {
xfs_ilock(ip, XFS_ILOCK_SHARED);
/*
* We've fallen off the end of the file, so
* just return with what we've done so far.
*/
if (uiop->uio_offset >= ip->i_d.di_size) {
xfs_iunlock(ip, XFS_ILOCK_SHARED);
break;
}
nbmaps = XFS_READ_BMAPS;
xfs_iomap_read(ip, uiop->uio_offset, uiop->uio_resid,
bmaps, &nbmaps);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (error || (bmaps[0].pbsize == 0)) {
break;
}
bmapp = &bmaps[0];
read_bmaps = nbmaps;
/*
* The first time through this loop we kick off I/O on
* all the bmaps described by the iomap_read call.
* Subsequent passes just wait for each buffer needed
* to satisfy this request to complete. Buffers which
* are started in the first pass but are actually just
* read ahead buffers are never waited for, since uio_resid
* will go to 0 before we get to them.
*
* This works OK because iomap_read always tries to
* describe all the buffers we need to satisfy this
* read call plus the necessary read-ahead in the
* first call to it.
*/
while ((uiop->uio_resid != 0) && (nbmaps > 0)) {
bp = chunkread(vp, bmapp, read_bmaps, credp);
if (bp->b_flags & B_ERROR) {
error = geterror(bp);
break;
} else if (bp->b_resid != 0) {
buffer_bytes_ok = 0;
break;
} else {
buffer_bytes_ok = 1;
error = biomove(bp, bmapp->pboff,
bmapp->pbsize, UIO_READ,
uiop);
if (error) {
break;
}
}
brelse(bp);
read_bmaps = 1;
nbmaps--;
bmapp++;
}
} while (!error && (uiop->uio_resid != 0) && buffer_bytes_ok);
return error;
}
/*
* xfs_read
*
* This is a stub.
*/
int
xfs_read(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp)
{
struct reservation_id id;
xfs_inode_t *ip;
int type;
off_t offset;
size_t count;
int error;
ip = XFS_VTOI(vp);
ASSERT(ismrlocked(&ip->i_iolock, MR_ACCESS | MR_UPDATE) != 0);
type = ip->i_d.di_mode & IFMT;
ASSERT(type == IFREG || type == IFDIR ||
type == IFLNK || type == IFSOCK);
offset = uiop->uio_offset;
count = uiop->uio_resid;
#ifndef SIM
if (MANDLOCK(vp, ip->i_d.di_mode) &&
(error = chklock(vp, FREAD, offset, count, uiop->uio_fmode))) {
return error;
}
#endif
if (offset < 0)
return EINVAL;
if (count <= 0)
return 0;
switch (type) {
case IFREG:
/*
* Not ready for in-line files yet.
*/
ASSERT((ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS) ||
(ip->i_d.di_format == XFS_DINODE_FMT_BTREE));
#ifdef SIM
/*
* Need pid of client not of simulator process.
* This may not always be correct.
*/
id.pid = MAKE_REQ_PID(u.u_procp->p_pid - 1, 0);
#else
id.pid = MAKE_REQ_PID(u.u_procp->p_pid, 0);
#endif
id.ino = ip->i_ino;
error = xfs_grio_req(ip, &id, uiop, ioflag, credp, UIO_READ);
break;
case IFDIR:
case IFLNK:
error = EINVAL;
break;
case IFSOCK:
error = ENODEV;
break;
default:
ASSERT(0);
error = EINVAL;
}
return error;
}
/*
* Map the given I/O size and I/O alignment over the given extent.
* If we're at the end of the file and the underlying extent is
* delayed alloc, make sure we extend out to the
* next m_writeio_blocks boundary. Otherwise make sure that we
* are confined to the given extent.
*/
STATIC void
xfs_write_bmap(xfs_mount_t *mp,
xfs_bmbt_irec_t *imapp,
struct bmapval *bmapp,
int iosize,
xfs_fileoff_t ioalign,
__int64_t isize)
{
int extra_blocks;
xfs_fileoff_t size_diff;
xfs_fileoff_t ext_offset;
xfs_fsblock_t start_block;
off_t last_imap_byte;
if (ioalign < imapp->br_startoff) {
/*
* The desired alignment doesn't end up on this
* extent. Move up to the beginning of the extent.
* Subtract whatever we drop from the iosize so that
* we stay aligned on iosize boundaries.
*/
size_diff = imapp->br_startoff - ioalign;
iosize -= (int)size_diff;
ASSERT(iosize > 0);
ext_offset = 0;
bmapp->offset = imapp->br_startoff;
} else {
/*
* The alignment requested fits on this extent,
* so use it.
*/
ext_offset = ioalign - imapp->br_startoff;
bmapp->offset = ioalign;
}
start_block = imapp->br_startblock;
ASSERT(start_block != HOLESTARTBLOCK);
if (start_block != DELAYSTARTBLOCK) {
bmapp->bn = start_block + ext_offset;
bmapp->eof = 0;
} else {
bmapp->bn = -1;
bmapp->eof = BMAP_DELAY;
}
bmapp->length = iosize;
/*
* If the iosize from our offset extends beyond the end of
* the extent and we're not at the end of the file or the
* underlying extent is real rather than delayed, then trim
* down length to match that of the extent.
*/
extra_blocks = (int)((bmapp->offset + bmapp->length) -
(imapp->br_startoff + imapp->br_blockcount));
last_imap_byte = xfs_fsb_to_b(mp, imapp->br_startoff +
imapp->br_blockcount);
if ((extra_blocks > 0) &&
((last_imap_byte < isize) ||
(imapp->br_startblock != DELAYSTARTBLOCK))) {
bmapp->length -= extra_blocks;
ASSERT(bmapp->length > 0);
}
bmapp->bsize = xfs_fsb_to_b(mp, bmapp->length);
}
/*
* This routine is called to handle zeroing the pages which overlap
* the end of the file if the user seeks and writes beyond the EOF.
* This is necessary because those pages in the buffer which used
* to be beyond EOF and therefore invalid become valid when isize
* is extended beyond them.
*
* We also zero any space left in the last block of the file so that
* we don't re-read garbage from it later.
*/
void
xfs_zero_eof(xfs_inode_t *ip,
off_t offset,
__int64_t isize,
cred_t *credp)
{
xfs_fileoff_t last_fsb;
__int64_t last_byte;
off_t page_start;
off_t ioalign;
xfs_mount_t *mp;
buf_t *bp;
int iosize;
int page_off;
pfd_t *pfdp;
vnode_t *vp;
int nimaps;
int zero_offset;
int zero_len;
xfs_bmbt_irec_t imap;
struct bmapval bmap;
ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
ASSERT(offset > isize);
mp = ip->i_mount;
vp = XFS_ITOV(ip);
ioalign = XFS_WRITEIO_ALIGN(mp, isize);
if (ioalign == isize) {
/*
* The buffer containing the last byte of the file
* would end at that last byte, so there is nothing
* to zero.
*/
return;
}
/*
* Zero any pages beyond the current EOF. These pages
* may exist up to writeio size beyond the EOF.
*/
iosize = (1 << mp->m_writeio_log);
last_byte = isize + iosize;
if (last_byte > offset) {
last_byte = offset;
}
page_off = poff(isize);
page_start = btoct(isize);
while (page_start < last_byte) {
pfdp = pfind(vp, page_start, VM_ATTACH);
if (pfdp != NULL) {
page_zero(pfdp, 0, page_off, NBPP - page_off);
pageflags(pfdp, P_HOLE, 1);
pagefree(pfdp);
}
page_off = 0;
page_start += NBPP;
}
last_fsb = xfs_b_to_fsbt(mp, isize);
/*
* If isize is fs block aligned, then there is no block
* to zero.
*/
if (last_fsb == xfs_b_to_fsb(mp, isize)) {
return;
}
nimaps = 1;
(void) xfs_bmapi(NULL, ip, last_fsb, 1, 0, NULLFSBLOCK, 0, &imap,
&nimaps, NULL);
ASSERT(nimaps > 0);
/*
* If the block underlying isize is just a hole, then there
* is nothing to zero.
*/
if (imap.br_startblock == HOLESTARTBLOCK) {
return;
}
/*
* Get a buffer for the last block, zero the part beyond the
* EOF, and write it out async. We need to drop the ilock
* while we do this so we don't deadlock when the buffer cache
* calls back to us.
*/
xfs_iunlock(ip, XFS_ILOCK_EXCL);
bmap.offset = xfs_fsb_to_bb(mp, last_fsb);
bmap.length = xfs_fsb_to_bb(mp, 1);
bmap.bsize = BBTOB(bmap.length);
bmap.pboff = 0;
bmap.pbsize = bmap.bsize;
if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
bmap.pbdev = mp->m_rtdev;
} else {
bmap.pbdev = mp->m_dev;
}
bmap.eof = BMAP_EOF;
if (imap.br_startblock != DELAYSTARTBLOCK) {
bmap.bn = xfs_fsb_to_daddr(mp, imap.br_startblock);
} else {
bmap.bn = -1;
bmap.eof |= BMAP_DELAY;
}
bp = chunkread(XFS_ITOV(ip), &bmap, 1, credp);
/*
* We did the zeroing in the page loop above.
* Just write it out.
*/
bawrite(bp);
xfs_ilock(ip, XFS_ILOCK_EXCL);
return;
}
STATIC void
xfs_iomap_write(xfs_inode_t *ip,
off_t offset,
size_t count,
struct bmapval *bmapp,
int *nbmaps)
{
xfs_fileoff_t offset_fsb;
xfs_fileoff_t ioalign;
xfs_fileoff_t next_offset_fsb;
xfs_fileoff_t last_fsb;
xfs_fileoff_t bmap_end_fsb;
off_t next_offset;
__int64_t isize;
int nimaps;
unsigned int iosize;
unsigned int writing_bytes;
short filled_bmaps;
short x;
size_t count_remaining;
xfs_mount_t *mp;
struct bmapval *curr_bmapp;
struct bmapval *next_bmapp;
struct bmapval *last_bmapp;
xfs_bmbt_irec_t *curr_imapp;
xfs_bmbt_irec_t *last_imapp;
#define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP
xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS];
ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
mp = ip->i_mount;
isize = ip->i_d.di_size;
offset_fsb = xfs_b_to_fsbt(mp, offset);
nimaps = XFS_WRITE_IMAPS;
last_fsb = xfs_b_to_fsb(mp, offset + count);
(void) xfs_bmapi(NULL, ip, offset_fsb,
(xfs_extlen_t)(last_fsb - offset_fsb),
XFS_BMAPI_DELAY | XFS_BMAPI_WRITE |
XFS_BMAPI_ENTIRE, NULLFSBLOCK, 1, imap,
&nimaps, NULL);
iosize = mp->m_writeio_blocks;
ioalign = XFS_WRITEIO_ALIGN(mp, offset);
ioalign = xfs_b_to_fsbt(mp, ioalign);
/*
* Now map our desired I/O size and alignment over the
* extents returned by xfs_bmapi().
*/
xfs_write_bmap(mp, imap, bmapp, iosize, ioalign, isize);
ASSERT((bmapp->length > 0) &&
(offset >= xfs_fsb_to_b(mp, bmapp->offset)));
/*
* A bmap is the EOF bmap when it reaches to or beyond the current
* inode size AND it encompasses the last block allocated to the
* file. Beyond the inode size is not good enough, because we
* could be writing more in this very request beyond what we
* are willing to describe in a single bmap.
*/
bmap_end_fsb = bmapp->offset + bmapp->length;
if ((nimaps == 1) &&
(bmap_end_fsb >= imap[0].br_startoff + imap[0].br_blockcount) &&
(xfs_fsb_to_b(mp, bmap_end_fsb) >= isize)) {
bmapp->eof |= BMAP_EOF;
}
bmapp->pboff = offset - xfs_fsb_to_b(mp, bmapp->offset);
writing_bytes = bmapp->bsize - bmapp->pboff;
if (writing_bytes > count) {
/*
* The mapping is for more bytes than we're actually
* going to write, so trim writing_bytes so we can
* get bmapp->pbsize right.
*/
writing_bytes = count;
}
bmapp->pbsize = writing_bytes;
/*
* Map more buffers if the first does not map the entire
* request. We do this until we run out of bmaps, imaps,
* or bytes to write.
*/
filled_bmaps = 1;
if ((*nbmaps > 1) &&
((nimaps > 1) || (bmapp->offset + bmapp->length <
imap[0].br_startoff + imap[0].br_blockcount)) &&
(writing_bytes < count)) {
curr_bmapp = &bmapp[0];
next_bmapp = &bmapp[1];
last_bmapp = &bmapp[*nbmaps - 1];
curr_imapp = &imap[0];
last_imapp = &imap[nimaps - 1];
count_remaining = count - writing_bytes;
/*
* curr_bmapp is always the last one we filled
* in, and next_bmapp is always the next one to
* be filled in.
*/
while (next_bmapp <= last_bmapp) {
next_offset_fsb = curr_bmapp->offset +
curr_bmapp->length;
if (next_offset_fsb <
(curr_imapp->br_startoff +
curr_imapp->br_blockcount)) {
/*
* I'm still on the same extent, so
* the last bmap must have ended on
* a writeio_blocks boundary. Thus,
* we just start where the last one
* left off.
*/
ASSERT((xfs_fsb_to_b(mp, next_offset_fsb) &
((1 << mp->m_writeio_log) - 1))==0);
xfs_write_bmap(mp, curr_imapp, next_bmapp,
iosize, next_offset_fsb,
isize);
} else {
curr_imapp++;
if (curr_imapp <= last_imapp) {
/*
* We're moving on to the next
* extent. Since we try to end
* all buffers on writeio_blocks
* boundaries, round next_offset
* down to a writeio_blocks boundary
* before calling xfs_write_bmap().
*
* XXXajs
* Adding a macro to writeio align
* fsblocks would be good to reduce
* the bit shifting here.
*/
ioalign = xfs_fsb_to_b(mp,
next_offset_fsb);
ioalign = XFS_WRITEIO_ALIGN(mp,
ioalign);
ioalign = xfs_b_to_fsbt(mp, ioalign);
xfs_write_bmap(mp, curr_imapp,
next_bmapp, iosize,
ioalign, isize);
} else {
/*
* We're out of imaps. The caller
* will have to call again to map
* the rest of the write request.
*/
break;
}
}
/*
* The write must start at offset 0 in this bmap
* since we're just continuing from the last
* buffer. Thus the request offset in the buffer
* indicated by pboff must be 0.
*/
next_bmapp->pboff = 0;
/*
* The request size within this buffer is the
* entire buffer unless the count of bytes to
* write runs out.
*/
next_offset = xfs_fsb_to_b(mp, next_offset_fsb);
writing_bytes = next_bmapp->bsize;
if (writing_bytes > count_remaining) {
writing_bytes = count_remaining;
}
next_bmapp->pbsize = writing_bytes;
count_remaining -= writing_bytes;
ASSERT(count_remaining >= 0);
filled_bmaps++;
curr_bmapp++;
next_bmapp++;
/*
* A bmap is the EOF bmap when it reaches to
* or beyond the current inode size AND it
* encompasses the last block allocated to the
* file. Beyond the inode size is not good
* enough, because we could be writing more
* in this very request beyond what we
* are willing to describe in a single bmap.
*/
bmap_end_fsb = curr_bmapp->offset +
curr_bmapp->length;
if ((curr_imapp == last_imapp) &&
(bmap_end_fsb >= curr_imapp->br_startoff +
curr_imapp->br_blockcount) &&
(xfs_fsb_to_b(mp, bmap_end_fsb) >= isize)) {
curr_bmapp->eof |= BMAP_EOF;
}
}
}
*nbmaps = filled_bmaps;
for (x = 0; x < filled_bmaps; x++) {
curr_bmapp = &bmapp[x];
if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
curr_bmapp->pbdev = mp->m_rtdev;
} else {
curr_bmapp->pbdev = mp->m_dev;
}
curr_bmapp->offset = xfs_fsb_to_bb(mp, curr_bmapp->offset);
curr_bmapp->length = xfs_fsb_to_bb(mp, curr_bmapp->length);
if (curr_bmapp->bn != -1) {
curr_bmapp->bn =
xfs_fsb_to_daddr(mp, curr_bmapp->bn);
}
}
}
int
xfs_write_file(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp)
{
#define XFS_WRITE_BMAPS 4
struct bmapval bmaps[XFS_WRITE_BMAPS];
struct bmapval *bmapp;
int nbmaps;
buf_t *bp;
int buffer_bytes_ok;
xfs_inode_t *ip;
int error;
int eof_zeroed;
__int64_t isize;
ip = XFS_VTOI(vp);
error = 0;
buffer_bytes_ok = 0;
eof_zeroed = 0;
/*
* i_new_size is used by xfs_iomap_read() when the chunk
* cache code calls back into the file system through
* xfs_bmap(). This way we can tell where the end of
* file is going to be even though we haven't yet updated
* ip->i_d.di_size. This is guarded by the iolock which
* is held exclusively through here.
*/
ip->i_new_size = uiop->uio_offset + uiop->uio_resid;
/*
* Loop until uiop->uio_resid, which is the number of bytes the
* caller has requested to write, goes to 0 or we get an error.
* Each call to xfs_iomap_write() tries to map as much of the
* request as it can in mp->m_writeio_blks sized chunks.
*/
do {
xfs_ilock(ip, XFS_ILOCK_EXCL);
isize = ip->i_d.di_size;
if (ip->i_new_size < isize) {
ip->i_new_size = isize;
}
/*
* If we've seeked passed the EOF to do this write,
* then we need to make sure that any buffer overlapping
* the EOF is zeroed beyond the EOF.
*/
if (!eof_zeroed &&
(uiop->uio_offset > isize) &&
(isize != 0)) {
xfs_zero_eof(ip, uiop->uio_offset, isize, credp);
eof_zeroed = 1;
}
nbmaps = XFS_WRITE_BMAPS;
xfs_iomap_write(ip, uiop->uio_offset, uiop->uio_resid,
bmaps, &nbmaps);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
if (error || (bmaps[0].pbsize == 0)) {
break;
}
bmapp = &bmaps[0];
/*
* Each pass through the loop writes another buffer
* to the file. For big requests, iomap_write will
* have given up multiple bmaps to use so we make fewer
* calls to it on big requests than if it only gave
* us one at a time.
*/
while ((uiop->uio_resid != 0) && (nbmaps > 0)) {
/*
* If the write doesn't completely overwrite
* the buffer and we're not writing from
* the beginning of the buffer to the end
* of the file then we need to read the
* buffer.
*
* Reading the buffer will send it to xfs_strategy
* which will take care of zeroing the holey
* parts of the buffer and coordinating with
* other, simultaneous writers.
*/
if ((bmapp->pbsize != bmapp->bsize) &&
!((bmapp->pboff == 0) &&
(uiop->uio_offset >= isize))) {
bp = chunkread(vp, bmapp, 1, credp);
} else {
bp = getchunk(vp, bmapp, credp);
}
/*
* XXXajs
* The error handling below needs more work.
*/
if (bp->b_flags & B_ERROR) {
error = geterror(bp);
brelse(bp);
break;
}
if (error = biomove(bp, bmapp->pboff, bmapp->pbsize,
UIO_WRITE, uiop)) {
if (!(bp->b_flags & B_DONE)) {
bp->b_flags |= B_STALE | B_DONE |
B_ERROR;
}
brelse(bp);
break;
}
/*
* If we've grown the file, get back the
* inode lock and move di_size up to the
* new size. It may be that someone else
* made it even bigger, so be careful not
* to shrink it.
*
* Noone could have shrunken the file, because
* we are holding the iolock shared.
*/
if (uiop->uio_offset > isize) {
xfs_ilock(ip, XFS_ILOCK_EXCL);
if (uiop->uio_offset > ip->i_d.di_size) {
ip->i_d.di_size = uiop->uio_offset;
ip->i_update_core = 1;
isize = uiop->uio_offset;
}
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}
if (uiop->uio_fmode & FSYNC) {
bwrite(bp);
} else {
bdwrite(bp);
}
bmapp++;
nbmaps--;
}
} while ((uiop->uio_resid > 0) && !error);
ip->i_new_size = 0;
return error;
}
/*
* xfs_write
*
* This is a stub.
*/
int
xfs_write(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp)
{
struct reservation_id id;
xfs_inode_t *ip;
int type;
off_t offset;
size_t count;
int error;
int n;
int resid;
timestruc_t tv;
ip = XFS_VTOI(vp);
ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
type = ip->i_d.di_mode & IFMT;
ASSERT(type == IFREG || type == IFDIR ||
type == IFLNK || type == IFSOCK);
if (ioflag & IO_APPEND) {
/*
* In append mode, start at the end of the file.
* Since I've got the iolock exclusive I can look
* at di_size.
*/
uiop->uio_offset = ip->i_d.di_size;
}
offset = uiop->uio_offset;
count = uiop->uio_resid;
#ifndef SIM
if (MANDLOCK(vp, ip->i_d.di_mode) &&
(error = chklock(vp, FWRITE, offset, count, uiop->uio_fmode))) {
return error;
}
#endif
if ((offset < 0) || ((offset + count) > XFS_MAX_FILE_OFFSET)) {
return EINVAL;
}
if (count <= 0) {
return 0;
}
switch (type) {
case IFREG:
n = uiop->uio_limit - uiop->uio_offset;
if (n <= 0) {
return EFBIG;
}
if (n < uiop->uio_resid) {
resid = uiop->uio_resid - n;
uiop->uio_resid = n;
} else {
resid = 0;
}
#ifdef SIM
/*
* Need pid of client not of simulator process.
* This may not always be correct.
*/
id.pid = MAKE_REQ_PID(u.u_procp->p_pid - 1, 0);
#else
id.pid = MAKE_REQ_PID(u.u_procp->p_pid, 0);
#endif
id.ino = ip->i_ino;
error = xfs_grio_req( ip, &id, uiop, ioflag, credp, UIO_WRITE);
/*
* Add back whatever we refused to do because of
* uio_limit.
*/
uiop->uio_resid += resid;
/*
* We've done at least a partial write, so don't
* return an error on this call. Also update the
* timestamps since we changed the file.
*
* XXXajs
* Are these the right timestamps?
*/
if (count != uiop->uio_resid) {
error = 0;
nanotime(&tv);
ip->i_d.di_mtime.t_sec = tv.tv_sec;
ip->i_d.di_ctime.t_sec = tv.tv_sec;
ip->i_update_core = 1;
}
break;
case IFDIR:
case IFLNK:
return EINVAL;
case IFSOCK:
return ENODEV;
default:
ASSERT(0);
return EINVAL;
}
return error;
}
/*
* This is the xFS entry point for VOP_BMAP().
* It simply switches based on the given flags
* to either xfs_iomap_read() or xfs_iomap_write().
* This cannot be used to grow a file or to read
* beyond the end of the file.
*
* The caller is required to be holding the inode's
* iolock in at least shared mode.
*/
int
xfs_bmap(vnode_t *vp,
off_t offset,
ssize_t count,
int flags,
cred_t *credp,
struct bmapval *bmapp,
int *nbmaps)
{
xfs_inode_t *ip;
ip = XFS_VTOI(vp);
ASSERT((ip->i_d.di_mode & IFMT) == IFREG);
ASSERT(ismrlocked(&ip->i_iolock, MR_ACCESS | MR_UPDATE) != 0);
ASSERT((flags == B_READ) || (flags == B_WRITE));
if (flags == B_READ) {
xfs_ilock(ip, XFS_ILOCK_SHARED);
xfs_iomap_read(ip, offset, count, bmapp, nbmaps);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
} else {
xfs_ilock(ip, XFS_ILOCK_EXCL);
ASSERT(ip->i_d.di_size >= (offset + count));
xfs_iomap_write(ip, offset, count, bmapp, nbmaps);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}
return 0;
}
/*
* Set up rbp so that it points to the memory attached to bp
* from rbp_offset from the start of bp for rbp_len bytes.
*/
STATIC void
xfs_overlap_bp(buf_t *bp,
buf_t *rbp,
uint rbp_offset,
uint rbp_len)
{
int pgbboff;
int bytes_off;
pfd_t *pfdp;
if (BP_ISMAPPED(bp)) {
/*
* The real buffer is already mapped, so just use
* its virtual memory for ourselves.
*/
rbp->b_un.b_addr = bp->b_un.b_addr + rbp_offset;
rbp->b_bcount = rbp_len;
rbp->b_bufsize = rbp_len;
} else {
/*
* The real buffer is not yet mapped to virtual memory.
* Just get the subordinate buffer's page pointers
* set up and make it a PAGEIO buffer like the real one.
*
* First find the first page of rbp. We do this by
* walking the list of pages in bp until we find the
* one containing the start of rbp. Note that neither
* bp nor rbp are required to start on page boundaries.
*/
bytes_off = rbp_offset + BBTOB(dpoff(bp->b_offset));
pfdp = NULL;
pfdp = getnextpg(bp, pfdp);
ASSERT(pfdp != NULL);
while (bytes_off >= NBPP) {
pfdp = getnextpg(bp, pfdp);
ASSERT(pfdp != NULL);
bytes_off -= NBPP;
}
rbp->b_pages = pfdp;
rbp->b_bcount = rbp_len;
rbp->b_offset = bp->b_offset + BTOBB(rbp_offset);
pgbboff = dpoff(rbp->b_offset);
rbp->b_bufsize = ctob(dtop(pgbboff + BTOBB(rbp_len)));
rbp->b_flags |= B_PAGEIO;
#ifndef SIM
if (pgbboff != 0) {
bp_mapin(rbp);
}
#endif
}
rbp->b_blkno = bp->b_blkno + BTOBB(rbp_offset);
rbp->b_remain = 0;
rbp->b_vp = bp->b_vp;
rbp->b_edev = bp->b_edev;
rbp->b_flags |= (bp->b_flags & (B_UNCACHED | B_ASYNC));
}
/*
* Zero the given bp from data_offset from the start of it for data_len
* bytes.
*/
STATIC void
xfs_zero_bp(buf_t *bp,
int data_offset,
int data_len)
{
pfd_t *pfdp;
caddr_t page_addr;
int len;
data_offset += BBTOB(dpoff(bp->b_offset));
pfdp = NULL;
pfdp = getnextpg(bp, pfdp);
ASSERT(pfdp != NULL);
while (data_offset >= NBPP) {
pfdp = getnextpg(bp, pfdp);
ASSERT(pfdp != NULL);
data_offset -= NBPP;
}
ASSERT(data_offset >= 0);
while (data_len > 0) {
page_addr = page_mapin(pfdp, (bp->b_flags & B_UNCACHED ?
VM_UNCACHED : 0), 0);
len = MIN(data_len, NBPP - data_offset);
bzero(page_addr + data_offset, len);
data_len -= len;
data_offset = 0;
page_mapout(page_addr);
pfdp = getnextpg(bp, pfdp);
}
}
/*
* "Read" in a buffer whose b_blkno is -1. This means that
* at the time the buffer was created there was no underlying
* backing store for the range of the file covered by the bp.
* To figure out the current state of things, we lock the inode
* and call xfs_bmapi() to look at the current extents format.
* If we're over a hole or delayed allocation space we simply
* zero the corresponding portions of the buffer. For parts
* over real disk space we need to read in the stuff from disk.
*/
STATIC void
xfs_strat_read(vnode_t *vp,
buf_t *bp)
{
xfs_fileoff_t offset_fsb;
xfs_fileoff_t map_start_fsb;
xfs_fileoff_t imap_offset;
xfs_extlen_t count_fsb;
xfs_extlen_t imap_blocks;
__int64_t isize;
off_t offset;
off_t end_offset;
int x;
caddr_t datap;
buf_t *rbp;
xfs_mount_t *mp;
xfs_inode_t *ip;
int data_bytes;
int data_offset;
int data_len;
int nimaps;
#define XFS_STRAT_READ_IMAPS 4
xfs_bmbt_irec_t imap[XFS_STRAT_READ_IMAPS];
ASSERT(bp->b_blkno == -1);
ip = XFS_VTOI(vp);
mp = XFS_VFSTOM(vp->v_vfsp);
offset_fsb = xfs_bb_to_fsbt(mp, bp->b_offset);
/*
* Only read up to the EOF.
*/
isize = ip->i_d.di_size;
offset = BBTOB(bp->b_offset);
end_offset = offset + bp->b_bcount;
if ((offset < isize) && (end_offset > isize)) {
count_fsb = xfs_b_to_fsb(mp, isize - offset);
} else {
count_fsb = xfs_b_to_fsb(mp, bp->b_bcount);
}
map_start_fsb = offset_fsb;
xfs_ilock(ip, XFS_ILOCK_SHARED);
while (count_fsb != 0) {
nimaps = XFS_STRAT_READ_IMAPS;
(void) xfs_bmapi(NULL, ip, map_start_fsb, count_fsb, 0,
NULLFSBLOCK, 0, imap, &nimaps, NULL);
ASSERT(nimaps >= 1);
for (x = 0; x < nimaps; x++) {
imap_offset = imap[x].br_startoff;
ASSERT(imap_offset == map_start_fsb);
imap_blocks = imap[x].br_blockcount;
ASSERT(imap_blocks <= count_fsb);
if ((imap[x].br_startblock == DELAYSTARTBLOCK) ||
(imap[x].br_startblock == HOLESTARTBLOCK)) {
/*
* This is either a hole or a delayed
* alloc extent. Either way, just fill
* it with zeroes.
*/
#ifndef SIM
datap = bp_mapin(bp);
datap += xfs_fsb_to_b(mp, imap_offset -
offset_fsb);
data_bytes = xfs_fsb_to_b(mp, imap_blocks);
bzero(datap, data_bytes);
#else /* SIM */
ASSERT(bp->b_flags & B_PAGEIO);
data_offset = xfs_fsb_to_b(mp, imap_offset -
offset_fsb);
data_len = xfs_fsb_to_b(mp, imap_blocks);
xfs_zero_bp(bp, data_offset, data_len);
#endif /* SIM */
} else {
/*
* The extent really exists on disk, so
* read it in.
*/
rbp = getrbuf(KM_SLEEP);
data_offset = xfs_fsb_to_b(mp, imap_offset -
offset_fsb);
data_len = xfs_fsb_to_b(mp, imap_blocks);
xfs_overlap_bp(bp, rbp, data_offset,
data_len);
rbp->b_flags |= B_READ;
rbp->b_flags &= ~B_ASYNC;
bdstrat(bmajor(rbp->b_edev), rbp);
iowait(rbp);
if (rbp->b_flags & B_ERROR) {
bp->b_flags |= B_ERROR;
bp->b_error = rbp->b_error;
}
#ifndef SIM
if (BP_ISMAPPED(rbp)) {
bp_mapout(rbp);
}
#endif
freerbuf(rbp);
}
count_fsb -= imap_blocks;
map_start_fsb += imap_blocks;
}
}
xfs_iunlock(ip, XFS_ILOCK_SHARED);
iodone(bp);
}
/*
* xfs_strat_write_count
*
* Figure out the number of fs blocks underlying the given
* delayed allocation buffer. There may be a mix of allocated
* and delayed allocation extents beneath the buffer, but there
* should only be a hole (if any) at the end of the buffer.
* The hole would be the result of the aggressive buffer allocation
* we do (past the EOF) when writing a file. It may even be that
* the entire buffer sits over a hole. This is from the case where
* pdflush() turns one of our extra pages into a buffer.
*/
STATIC xfs_extlen_t
xfs_strat_write_count(xfs_inode_t *ip,
xfs_fileoff_t offset_fsb,
xfs_extlen_t buf_fsb,
xfs_bmbt_irec_t *imap,
int imap_count)
{
xfs_fileoff_t off_fsb;
xfs_extlen_t count_fsb;
boolean_t done;
int nimaps;
int n;
ASSERT(ismrlocked(&(ip->i_lock), MR_ACCESS | MR_UPDATE) != 0);
off_fsb = offset_fsb;
count_fsb = 0;
done = B_FALSE;
while ((count_fsb < buf_fsb) && (!done)) {
nimaps = imap_count;
(void) xfs_bmapi(NULL, ip, (off_fsb + count_fsb),
(buf_fsb - count_fsb), 0, NULLFSBLOCK, 0,
imap, &nimaps, NULL);
ASSERT(nimaps > 0);
n = 0;
while (n < nimaps) {
if (imap[n].br_startblock == HOLESTARTBLOCK) {
/*
* We've hit the hole at the end of the
* buffer, so that's it. We assert
* that the hole we've found extends
* all the way to the end of the buffer.
*/
ASSERT((imap[n].br_startoff +
imap[n].br_blockcount) ==
(offset_fsb + buf_fsb));
done = B_TRUE;
break;
}
count_fsb += imap[n].br_blockcount;
ASSERT(count_fsb <= buf_fsb);
n++;
}
}
return count_fsb;
}
/*
* This is the completion routine for the heap-allocated buffers
* used to write out a buffer which becomes fragmented during
* xfs_strat_write(). It must coordinate with xfs_strat_write()
* to properly mark the lead buffer as done when necessary and
* to free the subordinate buffer.
*/
STATIC void
xfs_strat_write_relse(buf_t *rbp)
{
int s;
buf_t *leader;
buf_t *forw;
buf_t *back;
s = splockspl(xfs_strat_lock, splhi);
ASSERT(rbp->b_flags & B_DONE);
forw = (buf_t*)rbp->b_fsprivate2;
back = (buf_t*)rbp->b_fsprivate;
ASSERT(back != NULL);
ASSERT(back->b_fsprivate2 == rbp);
ASSERT((forw == NULL) || (forw->b_fsprivate == rbp));
/*
* Pull ourselves from the list.
*/
back->b_fsprivate2 = forw;
if (forw != NULL) {
forw->b_fsprivate = back;
}
if ((forw == NULL) &&
(back->b_flags & B_LEADER) &&
!(back->b_flags & B_PARTIAL)) {
/*
* We are the only buffer in the list and the lead buffer
* has cleared the B_PARTIAL bit to indicate that all
* subordinate buffers have been issued. That means it
* is time to finish off the lead buffer.
*/
leader = back;
if (rbp->b_flags & B_ERROR) {
leader->b_flags |= B_ERROR;
leader->b_error = rbp->b_error;
}
leader->b_flags &= ~B_LEADER;
spunlockspl(xfs_strat_lock, s);
iodone(leader);
} else {
/*
* Either there are still other buffers in the list or
* not all of the subordinate buffers have yet been issued.
* In this case just pass any errors on to the lead buffer.
*/
while (!(back->b_flags & B_LEADER)) {
back = (buf_t*)back->b_fsprivate;
}
ASSERT(back != NULL);
ASSERT(back->b_flags & B_LEADER);
leader = back;
if (rbp->b_flags & B_ERROR) {
leader->b_flags |= B_ERROR;
leader->b_error = rbp->b_error;
}
spunlockspl(xfs_strat_lock, s);
}
rbp->b_fsprivate = NULL;
rbp->b_fsprivate2 = NULL;
rbp->b_relse = NULL;
#ifndef SIM
if (BP_ISMAPPED(rbp)) {
bp_mapout(rbp);
}
#endif
freerbuf(rbp);
}
STATIC void
xfs_strat_write(vnode_t *vp,
buf_t *bp)
{
xfs_fileoff_t offset_fsb;
xfs_fileoff_t map_start_fsb;
xfs_fileoff_t imap_offset;
xfs_fsblock_t first_block;
xfs_extlen_t count_fsb;
xfs_extlen_t imap_blocks;
int x;
caddr_t datap;
buf_t *rbp;
xfs_mount_t *mp;
xfs_inode_t *ip;
xfs_trans_t *tp;
int error;
xfs_bmap_free_t free_list;
xfs_bmbt_irec_t *imapp;
int rbp_offset;
int rbp_len;
int set_lead = 0;
int s;
int imap_index;
int nimaps;
#define XFS_STRAT_WRITE_IMAPS 4
xfs_bmbt_irec_t imap[XFS_STRAT_WRITE_IMAPS];
ip = XFS_VTOI(vp);
mp = ip->i_mount;
bp->b_flags |= B_STALE;
/*
* Figure out what the underlying mappings look like.
* We need to map out all the space underlying the
* buffer to figure out whether the buffer extends
* beyond the allocated (or at least reserved) space
* and not to write that part.
*/
ASSERT(bp->b_blkno == -1);
offset_fsb = xfs_bb_to_fsbt(mp, bp->b_offset);
count_fsb = xfs_b_to_fsb(mp, bp->b_bcount);
xfs_ilock(ip, XFS_ILOCK_SHARED);
count_fsb = xfs_strat_write_count(ip, offset_fsb, count_fsb, imap,
XFS_STRAT_WRITE_IMAPS);
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (count_fsb == 0) {
/*
* The buffer sits entirely over a hole. Just mark
* it done and return.
*/
iodone(bp);
return;
}
map_start_fsb = offset_fsb;
while (count_fsb != 0) {
/*
* Set up a transaction with which to allocate the
* backing store for the file.
*/
tp = xfs_trans_alloc(mp, XFS_TRANS_FILE_WRITE);
/*
error = xfs_trans_reserve(tp, 0, XFS_DEFAULT_LOG_RES(mp),
0, 0);
For now reserve some space as a work-around.
*/
error = xfs_trans_reserve(tp, 20, XFS_DEFAULT_LOG_RES(mp),
0, 0);
ASSERT(error == 0);
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
xfs_trans_ihold(tp, ip);
/*
* Allocate the backing store for the file.
*/
XFS_BMAP_INIT(&free_list, &first_block);
nimaps = XFS_STRAT_WRITE_IMAPS;
first_block = xfs_bmapi(tp, ip, map_start_fsb, count_fsb,
XFS_BMAPI_WRITE, first_block, 1,
imap, &nimaps, &free_list);
ASSERT(nimaps > 0);
(void) xfs_bmap_finish(&tp, &free_list, first_block, 0);
xfs_trans_commit(tp, 0);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/*
* This is a quick check to see if the first time through
* was able to allocate a single extent over which to
* write
*/
if ((map_start_fsb == offset_fsb) &&
(imap[0].br_blockcount == count_fsb)) {
ASSERT(nimaps == 1);
bp->b_blkno = xfs_fsb_to_daddr(mp,
imap[0].br_startblock);
bp->b_bcount = xfs_fsb_to_b(mp, count_fsb);
bdstrat(bmajor(bp->b_edev), bp);
return;
}
/*
* Bmap couldn't manage to lay the buffer out as
* one extent, so we need to do multiple writes
* to push the data to the multiple extents.
* Write out the subordinate bps asynchronously
* and have their completion functions coordinate
* with the code at the end of this function to
* deal with marking our bp as done when they have
* ALL completed.
*/
imap_index = 0;
if (!set_lead) {
bp->b_flags |= B_LEADER | B_PARTIAL;
set_lead = 1;
}
while (imap_index < nimaps) {
rbp = getrbuf(KM_SLEEP);
imapp = &imap[imap_index];
ASSERT((imapp->br_startblock != DELAYSTARTBLOCK) &&
(imapp->br_startblock != HOLESTARTBLOCK));
imap_offset = imapp->br_startoff;
rbp_offset = xfs_fsb_to_b(mp, imap_offset - offset_fsb);
imap_blocks = imapp->br_blockcount;
rbp_len = xfs_fsb_to_b(mp, imap_blocks);
xfs_overlap_bp(bp, rbp, rbp_offset, rbp_len);
rbp->b_blkno = xfs_fsb_to_daddr(mp,
imapp->br_startblock);
/*
* Link the buffer into the list of subordinate
* buffers started at bp->b_fsprivate2. The
* subordinate buffers use b_fsprivate and
* b_fsprivate2 for back and forw pointers, but
* the lead buffer cannot use b_fsprivate.
* A subordinate buffer can always find the lead
* buffer by searching back through the fsprivate
* fields until it finds the buffer marked with
* B_LEADER.
*/
s = splockspl(xfs_strat_lock, splhi);
rbp->b_fsprivate = bp;
rbp->b_fsprivate2 = bp->b_fsprivate2;
if (bp->b_fsprivate2 != NULL) {
((buf_t*)(bp->b_fsprivate2))->b_fsprivate =
rbp;
}
bp->b_fsprivate2 = rbp;
spunlockspl(xfs_strat_lock, s);
rbp->b_relse = xfs_strat_write_relse;
bdstrat(bmajor(rbp->b_edev), rbp);
map_start_fsb += imapp->br_blockcount;
count_fsb -= imapp->br_blockcount;
ASSERT(count_fsb >= 0);
imap_index++;
}
}
/*
* Now that we've issued all the partial I/Os, check to see
* if they've all completed. If they have then mark the buffer
* as done, otherwise clear the B_PARTIAL flag in the buffer to
* indicate that the last subordinate buffer to complete should
* mark the buffer done.
*/
s = splockspl(xfs_strat_lock, splhi);
ASSERT((bp->b_flags & (B_DONE | B_PARTIAL)) == B_PARTIAL);
ASSERT(bp->b_flags & B_LEADER);
if (bp->b_fsprivate2 == NULL) {
/*
* All of the subordinate buffers have completed.
* Call iodone() to note that the I/O has completed.
*/
bp->b_flags &= ~(B_PARTIAL | B_LEADER);
spunlockspl(xfs_strat_lock, s);
iodone(bp);
return;
}
bp->b_flags &= ~B_PARTIAL;
spunlockspl(xfs_strat_lock, s);
return;
}
/*
* xfs_strategy
*
* This is where all the I/O and all the REAL allocations take
* place. For buffers with -1 for their b_blkno field, we need
* to do a bmap to figure out what to do with them. If it's a
* write we may need to do an allocation, while if it's a read
* we may either need to read from disk or do some block zeroing.
* If b_blkno specifies a real block, then all we need to do
* is pass the buffer on to the underlying driver.
*/
void
xfs_strategy(vnode_t *vp,
buf_t *bp)
{
xfs_mount_t *mp;
int s;
mp = XFS_VFSTOM(vp->v_vfsp);
/*
* If this is just a buffer whose underlying disk space
* is already allocated, then just do the requested I/O.
*/
if (bp->b_blkno >= 0) {
bdstrat(bmajor(bp->b_edev), bp);
return;
}
/*
* If we're reading, then we need to find out how the
* portion of the file required for this buffer is layed
* out and zero/read in the appropriate data.
*/
if (bp->b_flags & B_READ) {
xfs_strat_read(vp, bp);
return;
}
/*
* Here we're writing the file and probably need to allocate
* some underlying disk space. If the buffer is being written
* asynchronously by bdflush() then we queue if for the xfsds
* so that we won't put bdflush() to sleep.
*/
if ((bp->b_flags & (B_ASYNC | B_BDFLUSH)) == (B_ASYNC | B_BDFLUSH) &&
(xfsd_count > 0)) {
s = splock(xfsd_lock);
/*
* Queue the buffer at the end of the list.
*/
if (xfsd_list == NULL) {
bp->av_forw = bp;
bp->av_back = bp;
xfsd_list = bp;
} else {
bp->av_back = xfsd_list->av_back;
xfsd_list->av_back->av_forw = bp;
xfsd_list->av_back = bp;
bp->av_forw = xfsd_list;
}
xfsd_bufcount++;
cvsema(&xfsd_wait);
spunlock(xfsd_lock, s);
} else {
xfs_strat_write(vp, bp);
}
}
#ifndef SIM
/*
* This is the routine called by the xfs daemons as they enter the
* kernel. From here they wait in a loop for buffers which will
* require transactions to write out and process them as they come.
* This way we never force bdflush() to wait on one of our transactions,
* thereby keeping the system happier and preventing buffer deadlocks.
*/
int
xfsd(void)
{
int s;
buf_t *bp;
buf_t *forw;
buf_t *back;
/*
* Get rid of our address space, we're never returning to
* user space.
*/
vrelvm();
/*
* Make us a high non-degrading priority process like bdflush(),
* since that is who we're relieving of work.
*/
setinfoRunq(u.u_procp, RQRTPRI, NDPHIMIN);
/*
* We should never sleep at an interruptible priority, but
* just to make sure...
*/
if (setjmp(u.u_qsav)) {
cmn_err(CE_PANIC, "xfsd interrupted");
}
s = splock(xfsd_lock);
xfsd_count++;
while (1) {
while (xfsd_list == NULL) {
(void) spunlock_psema(xfsd_lock, s, &xfsd_wait,
PRIBIO);
s = splock(xfsd_lock);
}
/*
* Pull a buffer off of the list.
*/
bp = xfsd_list;
forw = bp->av_forw;
back = bp->av_back;
forw->av_back = back;
back->av_forw = forw;
if (forw == bp) {
xfsd_list = NULL;
} else {
xfsd_list = forw;
}
bp->av_forw = bp;
bp->av_back = bp;
xfsd_bufcount--;;
ASSERT(xfsd_bufcount >= 0);
spunlock(xfsd_lock, s);
ASSERT((bp->b_flags & (B_BUSY | B_ASYNC | B_READ)) ==
(B_BUSY | B_ASYNC));
xfs_strat_write(bp->b_vp, bp);
s = splock(xfsd_lock);
}
}
#endif /* !SIM */
struct dio_s {
struct vnode *vp;
struct cred *cr;
int ioflag;
};
/*
* xfs_diostrat()
* This routine issues the calls to the disk device strategy routine
* for file system reads and writes made using direct I/O from user
* space. In the case of a write request the I/Os are issued one
* extent at a time. In the case of a read request I/Os for each extent
* involved are issued at once.
*
* RETURNS:
* none
*/
int
xfs_diostrat( buf_t *bp)
{
struct dio_s *dp;
xfs_inode_t *ip;
xfs_trans_t *tp;
vnode_t *vp;
xfs_mount_t *mp;
xfs_bmbt_irec_t imaps[XFS_BMAP_MAX_NMAP], *imapp, *timapp;
buf_t *bps[XFS_BMAP_MAX_NMAP], *nbp;
xfs_fileoff_t offset_fsb, last_fsb;
xfs_fsblock_t firstfsb;
xfs_extlen_t blocks, count_fsb, total;
xfs_bmap_free_t free_list;
caddr_t base;
ssize_t bytes_this_req, resid, count, totxfer;
off_t offset, offset_this_req;
int i, j, error, writeflag, reccount;
int end_of_file, bufsissued, totresid, exist;
int ioflag, blk_algn, rt, numrtextents, rtextsize;
dp = (struct dio_s *)bp->b_private;
vp = dp->vp;
ip = XFS_VTOI(vp);
mp = XFS_VFSTOM(XFS_ITOV(ip)->v_vfsp);
base = bp->b_un.b_addr;
error = resid = totxfer = end_of_file = 0;
ioflag = dp->ioflag;
offset = BBTOB(bp->b_blkno);
blk_algn = 0;
totresid = count = bp->b_bcount;
/*
* Determine if this file is using the realtime volume.
*/
if ( ip->i_d.di_flags & XFS_DIFLAG_REALTIME ) {
rt = 1;
rtextsize = ip->i_d.di_extsize;
} else {
numrtextents = 0;
rtextsize = 0;
rt = 0;
}
ASSERT(!(bp->b_flags & B_DONE));
ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE) != 0);
/*
* Alignment checks are done in xfs_diordwr().
* Determine if the operation is a read or a write.
*/
if (bp->b_flags & B_READ) {
writeflag = 0;
} else {
writeflag = XFS_BMAPI_WRITE;
}
/*
* Check if the request is on a file system block boundary.
*/
if ( (offset % mp->m_sb.sb_blocksize) != 0 ) {
/*
* The request is NOT on a file system block boundary.
*/
blk_algn = BTOBB(offset % mp->m_sb.sb_blocksize);
}
/*
* Process the request until:
* 1) an I/O error occurs
* 2) end of file is reached.
* 3) end of device (driver error) occurs
* 4) request is completed.
*/
while ( !error && !end_of_file && !resid && count ) {
offset_fsb = xfs_b_to_fsbt( mp, offset );
last_fsb = xfs_b_to_fsb( mp, offset + count);
count_fsb = xfs_b_to_fsb( mp, count);
blocks = (xfs_extlen_t)(last_fsb - offset_fsb);
exist = 1;
XFS_BMAP_INIT(&free_list, &firstfsb);
if ( writeflag ) {
/*
* In the write case, need to call bmapi() with
* the read flag set first to determine the existing
* extents. This is done so that the correct amount
* of space can be reserved in the transaction
* structure.
*/
reccount = XFS_BMAP_MAX_NMAP;
xfs_ilock( ip, XFS_ILOCK_EXCL );
firstfsb = xfs_bmapi( tp, ip, offset_fsb,
count_fsb, 0, firstfsb, 0, imaps,
&reccount, 0);
/*
* Get a pointer to the current extent map.
* Writes will always be issued one at a time.
*/
reccount = 1;
imapp = &imaps[0];
count_fsb = imapp->br_blockcount;
if ((imapp->br_startblock == DELAYSTARTBLOCK) ||
(imapp->br_startblock == HOLESTARTBLOCK)) {
exist = 0;
}
/*
* If blocks are not yet allocated for this part of
* the file, allocate space for the transactions.
*/
if (!exist) {
if (rt) {
/*
* Round up to even number of extents.
*/
numrtextents = (count_fsb+rtextsize-1)/
rtextsize;
}
/*
* Setup transactions.
*/
tp = xfs_trans_alloc( mp, XFS_TRANS_FILE_WRITE);
error = xfs_trans_reserve( tp, count_fsb,
XFS_DEFAULT_LOG_RES(mp),
numrtextents, 0 );
if (error) {
/*
* Ran out of file system space.
* Free the transaction structure.
*/
ASSERT( error == ENOSPC );
xfs_trans_cancel(tp, 0);
xfs_iunlock( ip, XFS_ILOCK_EXCL);
break;
} else {
xfs_trans_ijoin(tp,ip,XFS_ILOCK_EXCL);
xfs_trans_ihold( tp, ip);
}
} else {
tp = NULL;
}
} else {
/*
* Read case.
* Read requests will be issued
* up to XFS_BMAP_MAX_MAP at a time.
*/
reccount = XFS_BMAP_MAX_NMAP;
imapp = &imaps[0];
xfs_ilock( ip, XFS_ILOCK_SHARED);
}
/*
* Issue the bmapi() call to get the extent info.
* In the case of write requests this call does the
* actual file space allocation.
*/
firstfsb = xfs_bmapi( tp, ip, offset_fsb, count_fsb,
writeflag, firstfsb, 0, imapp, &reccount, &free_list);
if ( writeflag ) {
/*
* Complete the bmapi() transactions.
*/
if (!exist) {
xfs_bmap_finish( &tp, &free_list, firstfsb, 0 );
xfs_trans_commit(tp , 0 );
}
xfs_iunlock( ip, XFS_ILOCK_EXCL);
} else {
xfs_iunlock( ip, XFS_ILOCK_SHARED);
}
/*
* xfs_bmapi() was unable to allocate space
*/
if (reccount == 0) {
error = ENOSPC;
break;
}
/*
* Run through each extent.
*/
bufsissued = 0;
for (i = 0; (i < reccount) && (!end_of_file) && (count); i++){
imapp = &imaps[i];
bytes_this_req = xfs_fsb_to_b(mp,
imapp->br_blockcount) - BBTOB(blk_algn);
offset_this_req = xfs_fsb_to_b(mp,
imapp->br_startoff) + BBTOB(blk_algn);
/*
* Check if this is the end of the file.
*/
if (offset_this_req +bytes_this_req >ip->i_d.di_size){
if ( writeflag ) {
/*
* File is being extended on a
* write, update the file size.
*/
ASSERT((vp->v_flag & VISSWAP) == 0);
xfs_ilock(ip, XFS_ILOCK_EXCL);
ip->i_d.di_size = offset_this_req +
bytes_this_req;
ip->i_update_core = 1;
xfs_iunlock(ip, XFS_ILOCK_EXCL);
} else {
/*
* If trying to read past end of
* file, shorten the request size.
*/
bytes_this_req = ip->i_d.di_size -
offset_this_req;
end_of_file = 1;
}
}
/*
* Reduce request size, if it
* is longer than user buffer.
*/
if ( bytes_this_req > count ) {
bytes_this_req = count;
}
/*
* Do not do I/O if there is a hole in the file.
*/
if (imapp->br_startblock != HOLESTARTBLOCK) {
/*
* Setup I/O request for this extent.
*/
bps[bufsissued++]= nbp = getphysbuf();
nbp->b_flags = bp->b_flags;
nbp->b_flags2 = bp->b_flags2;
if (ioflag & IO_GRIO)
nbp->b_flags2 |= B_GR_BUF;
nbp->b_error = 0;
nbp->b_proc = bp->b_proc;
nbp->b_edev = bp->b_edev;
if (rt) {
nbp->b_blkno = xfs_btod(mp,
imapp->br_startblock);
} else {
nbp->b_blkno = xfs_fsb_to_daddr(mp,
imapp->br_startblock) +
blk_algn;
}
nbp->b_bcount = bytes_this_req;
nbp->b_un.b_addr = base;
/*
* Issue I/O request.
*/
bdstrat( bmajor(nbp->b_edev), nbp );
if (error = geterror(nbp)) {
iowait( nbp );
nbp->b_flags = 0;
nbp->b_un.b_addr = 0;
putphysbuf( nbp );
bps[bufsissued--] = 0;
break;
}
} else {
/*
* Hole in file can only happen on read case.
*/
ASSERT(!writeflag);
/*
* Physio() has already mapped user address.
*/
bzero(base, bytes_this_req);
/*
* Bump the transfer count.
*/
totxfer += bytes_this_req;
}
/*
* update pointers for next round.
*/
base += bytes_this_req;
offset += bytes_this_req;
count -= bytes_this_req;
blk_algn= 0;
} /* end of for loop */
/*
* Wait for I/O completion and recover buffers.
*/
for ( j = 0; j < bufsissued ; j++) {
nbp = bps[j];
iowait( nbp );
if (!error)
error = geterror( nbp );
if (!error && !resid) {
resid = nbp->b_resid;
totxfer += (nbp->b_bcount - resid);
}
nbp->b_flags = 0;
nbp->b_un.b_addr = 0;
nbp->b_bcount = 0;
putphysbuf( nbp );
}
} /* end of while loop */
/*
* Fill in resid count for original buffer.
*/
bp->b_resid = totresid - totxfer;
/*
* Update the inode timestamp if file was written.
*/
if ( writeflag ) {
timestruc_t tv;
xfs_ilock(ip, XFS_ILOCK_EXCL);
if ((ip->i_d.di_mode & (ISUID|ISGID)) && dp->cr->cr_uid != 0){
ip->i_d.di_mode &= ~ISUID;
if (ip->i_d.di_mode & (IEXEC >> 3))
ip->i_d.di_mode &= ~ISGID;
}
nanotime( &tv );
ip->i_d.di_mtime.t_sec = ip->i_d.di_ctime.t_sec = tv.tv_sec;
ip->i_update_core = 1;
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}
/*
* Issue completion on the original buffer.
*/
bioerror( bp, error);
iodone( bp );
return(0);
}
/*
* xfs_diordwr()
* This routine sets up a buf structure to be used to perform
* direct I/O operations to user space. The user specified
* paramters are checked for alignment and size limitations. A buf
* structure is allocated an biophysio() is called.
*
* RETURNS:
* 0 on success
* errno on error
*/
int
xfs_diordwr(vnode_t *vp,
uio_t *uiop,
int ioflag,
cred_t *credp,
int rw)
{
xfs_inode_t *ip;
struct dio_s dp;
xfs_mount_t *mp;
buf_t *bp;
int error;
ip = XFS_VTOI(vp);
/*
* Check that the user buffer address, file offset, and
* request size are all multiples of BBSIZE. This prevents
* the need for read/modify/write operations.
*/
if ((((int)(uiop->uio_iov->iov_base)) & BBMASK) ||
(uiop->uio_offset & BBMASK) ||
(uiop->uio_resid & BBMASK)) {
#ifndef SIM
return EINVAL;
#endif
}
/*
* Do maxio check.
*/
if (uiop->uio_resid > ctob(v.v_maxdmasz)) {
#ifndef SIM
return EINVAL;
#endif
}
/*
* Use dio_s structure to pass file/credential
* information to file system strategy routine.
*/
dp.vp = vp;
dp.cr = credp;
dp.ioflag = ioflag;
/*
* Allocate local buf structure.
*/
bp = getphysbuf();
bp->b_private = &dp;
mp = XFS_VFSTOM(vp->v_vfsp);
if (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) {
bp->b_edev = mp->m_rtdev;
} else {
bp->b_edev = mp->m_dev;
}
/*
* Perform I/O operation.
*/
error = biophysio(xfs_diostrat, bp, bp->b_edev, rw,
(daddr_t)BTOBB(uiop->uio_offset), uiop);
/*
* Free local buf structure.
*/
bp->b_flags = 0;
#ifdef SIM
bp->b_un.b_addr = 0;
#endif
putphysbuf(bp);
return( error );
}
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