patch-2.4.27 linux-2.4.27/fs/xfs/linux/xfs_aops.c
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- Lines: 1301
- Date:
1969-12-31 16:00:00.000000000 -0800
- Orig file:
linux-2.4.26/fs/xfs/linux/xfs_aops.c
- Orig date:
2004-04-14 06:05:40.000000000 -0700
diff -urN linux-2.4.26/fs/xfs/linux/xfs_aops.c linux-2.4.27/fs/xfs/linux/xfs_aops.c
@@ -1,1300 +0,0 @@
-/*
- * Copyright (c) 2000-2004 Silicon Graphics, Inc. All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of version 2 of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
- *
- * Further, this software is distributed without any warranty that it is
- * free of the rightful claim of any third person regarding infringement
- * or the like. Any license provided herein, whether implied or
- * otherwise, applies only to this software file. Patent licenses, if
- * any, provided herein do not apply to combinations of this program with
- * other software, or any other product whatsoever.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write the Free Software Foundation, Inc., 59
- * Temple Place - Suite 330, Boston MA 02111-1307, USA.
- *
- * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
- * Mountain View, CA 94043, or:
- *
- * http://www.sgi.com
- *
- * For further information regarding this notice, see:
- *
- * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
- */
-
-#include "xfs.h"
-#include "xfs_inum.h"
-#include "xfs_log.h"
-#include "xfs_sb.h"
-#include "xfs_dir.h"
-#include "xfs_dir2.h"
-#include "xfs_trans.h"
-#include "xfs_dmapi.h"
-#include "xfs_mount.h"
-#include "xfs_bmap_btree.h"
-#include "xfs_alloc_btree.h"
-#include "xfs_ialloc_btree.h"
-#include "xfs_alloc.h"
-#include "xfs_btree.h"
-#include "xfs_attr_sf.h"
-#include "xfs_dir_sf.h"
-#include "xfs_dir2_sf.h"
-#include "xfs_dinode.h"
-#include "xfs_inode.h"
-#include "xfs_error.h"
-#include "xfs_rw.h"
-#include "xfs_iomap.h"
-#include <linux/iobuf.h>
-
-STATIC void xfs_count_page_state(struct page *, int *, int *, int *);
-STATIC void xfs_convert_page(struct inode *, struct page *,
- xfs_iomap_t *, void *, int, int);
-
-#if defined(XFS_RW_TRACE)
-void
-xfs_page_trace(
- int tag,
- struct inode *inode,
- struct page *page,
- int mask)
-{
- xfs_inode_t *ip;
- bhv_desc_t *bdp;
- vnode_t *vp = LINVFS_GET_VP(inode);
- loff_t isize = i_size_read(inode);
- loff_t offset = page->index << PAGE_CACHE_SHIFT;
- int delalloc = -1, unmapped = -1, unwritten = -1;
-
- if (page_has_buffers(page))
- xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
-
- bdp = vn_bhv_lookup(VN_BHV_HEAD(vp), &xfs_vnodeops);
- ip = XFS_BHVTOI(bdp);
- if (!ip->i_rwtrace)
- return;
-
- ktrace_enter(ip->i_rwtrace,
- (void *)((unsigned long)tag),
- (void *)ip,
- (void *)inode,
- (void *)page,
- (void *)((unsigned long)mask),
- (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
- (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
- (void *)((unsigned long)((isize >> 32) & 0xffffffff)),
- (void *)((unsigned long)(isize & 0xffffffff)),
- (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
- (void *)((unsigned long)(offset & 0xffffffff)),
- (void *)((unsigned long)delalloc),
- (void *)((unsigned long)unmapped),
- (void *)((unsigned long)unwritten),
- (void *)NULL,
- (void *)NULL);
-}
-#else
-#define xfs_page_trace(tag, inode, page, mask)
-#endif
-
-void
-linvfs_unwritten_done(
- struct buffer_head *bh,
- int uptodate)
-{
- page_buf_t *pb = (page_buf_t *)bh->b_private;
-
- ASSERT(buffer_unwritten(bh));
- bh->b_end_io = NULL;
- clear_buffer_unwritten(bh);
- if (!uptodate)
- pagebuf_ioerror(pb, EIO);
- if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
- pagebuf_iodone(pb, 1, 1);
- }
- end_buffer_io_async(bh, uptodate);
-}
-
-/*
- * Issue transactions to convert a buffer range from unwritten
- * to written extents.
- */
-STATIC void
-linvfs_unwritten_convert(
- xfs_buf_t *bp)
-{
- vnode_t *vp = XFS_BUF_FSPRIVATE(bp, vnode_t *);
- int error;
-
- BUG_ON(atomic_read(&bp->pb_hold) < 1);
- VOP_BMAP(vp, XFS_BUF_OFFSET(bp), XFS_BUF_SIZE(bp),
- BMAPI_UNWRITTEN, NULL, NULL, error);
- XFS_BUF_SET_FSPRIVATE(bp, NULL);
- XFS_BUF_CLR_IODONE_FUNC(bp);
- XFS_BUF_UNDATAIO(bp);
- iput(LINVFS_GET_IP(vp));
- pagebuf_iodone(bp, 0, 0);
-}
-
-STATIC int
-xfs_map_blocks(
- struct inode *inode,
- loff_t offset,
- ssize_t count,
- xfs_iomap_t *iomapp,
- int flags)
-{
- vnode_t *vp = LINVFS_GET_VP(inode);
- int error, niomaps = 1;
-
- if (((flags & (BMAPI_DIRECT|BMAPI_SYNC)) == BMAPI_DIRECT) &&
- (offset >= i_size_read(inode)))
- count = max_t(ssize_t, count, XFS_WRITE_IO_LOG);
-retry:
- VOP_BMAP(vp, offset, count, flags, iomapp, &niomaps, error);
- if ((error == EAGAIN) || (error == EIO))
- return -error;
- if (unlikely((flags & (BMAPI_WRITE|BMAPI_DIRECT)) ==
- (BMAPI_WRITE|BMAPI_DIRECT) && niomaps &&
- (iomapp->iomap_flags & IOMAP_DELAY))) {
- flags = BMAPI_ALLOCATE;
- goto retry;
- }
- if (flags & (BMAPI_WRITE|BMAPI_ALLOCATE)) {
- VMODIFY(vp);
- }
- return -error;
-}
-
-/*
- * Finds the corresponding mapping in block @map array of the
- * given @offset within a @page.
- */
-STATIC xfs_iomap_t *
-xfs_offset_to_map(
- struct page *page,
- xfs_iomap_t *iomapp,
- unsigned long offset)
-{
- loff_t full_offset; /* offset from start of file */
-
- ASSERT(offset < PAGE_CACHE_SIZE);
-
- full_offset = page->index; /* NB: using 64bit number */
- full_offset <<= PAGE_CACHE_SHIFT; /* offset from file start */
- full_offset += offset; /* offset from page start */
-
- if (full_offset < iomapp->iomap_offset)
- return NULL;
- if (iomapp->iomap_offset + iomapp->iomap_bsize > full_offset)
- return iomapp;
- return NULL;
-}
-
-STATIC void
-xfs_map_at_offset(
- struct page *page,
- struct buffer_head *bh,
- unsigned long offset,
- int block_bits,
- xfs_iomap_t *iomapp)
-{
- xfs_daddr_t bn;
- loff_t delta;
- int sector_shift;
-
- ASSERT(!(iomapp->iomap_flags & IOMAP_HOLE));
- ASSERT(!(iomapp->iomap_flags & IOMAP_DELAY));
- ASSERT(iomapp->iomap_bn != IOMAP_DADDR_NULL);
-
- delta = page->index;
- delta <<= PAGE_CACHE_SHIFT;
- delta += offset;
- delta -= iomapp->iomap_offset;
- delta >>= block_bits;
-
- sector_shift = block_bits - BBSHIFT;
- bn = iomapp->iomap_bn >> sector_shift;
- bn += delta;
- ASSERT((bn << sector_shift) >= iomapp->iomap_bn);
-
- lock_buffer(bh);
- bh->b_blocknr = bn;
- bh->b_dev = iomapp->iomap_target->pbr_kdev;
- set_buffer_mapped(bh);
- clear_buffer_delay(bh);
-}
-
-/*
- * Look for a page at index which is unlocked and contains our
- * unwritten extent flagged buffers at its head. Returns page
- * locked and with an extra reference count, and length of the
- * unwritten extent component on this page that we can write,
- * in units of filesystem blocks.
- */
-STATIC struct page *
-xfs_probe_unwritten_page(
- struct address_space *mapping,
- unsigned long index,
- xfs_iomap_t *iomapp,
- page_buf_t *pb,
- unsigned long max_offset,
- unsigned long *fsbs,
- unsigned int bbits)
-{
- struct page *page;
-
- page = find_trylock_page(mapping, index);
- if (!page)
- return 0;
-
- if (page->mapping && page_has_buffers(page)) {
- struct buffer_head *bh, *head;
- unsigned long p_offset = 0;
-
- *fsbs = 0;
- bh = head = page_buffers(page);
- do {
- if (!buffer_unwritten(bh))
- break;
- if (!xfs_offset_to_map(page, iomapp, p_offset))
- break;
- if (p_offset >= max_offset)
- break;
- xfs_map_at_offset(page, bh, p_offset, bbits, iomapp);
- set_buffer_unwritten_io(bh);
- bh->b_private = pb;
- p_offset += bh->b_size;
- (*fsbs)++;
- } while ((bh = bh->b_this_page) != head);
-
- if (p_offset)
- return page;
- }
-
- unlock_page(page);
- return NULL;
-}
-
-/*
- * Look for a page at index which is unlocked and not mapped
- * yet - clustering for mmap write case.
- */
-STATIC unsigned int
-xfs_probe_unmapped_page(
- struct address_space *mapping,
- unsigned long index,
- unsigned int pg_offset)
-{
- struct page *page;
- int ret = 0;
-
- page = find_trylock_page(mapping, index);
- if (!page)
- return 0;
-
- if (page->mapping && PageDirty(page)) {
- if (page_has_buffers(page)) {
- struct buffer_head *bh, *head;
-
- bh = head = page_buffers(page);
- do {
- if (buffer_mapped(bh) || !buffer_uptodate(bh))
- break;
- ret += bh->b_size;
- if (ret >= pg_offset)
- break;
- } while ((bh = bh->b_this_page) != head);
- } else
- ret = PAGE_CACHE_SIZE;
- }
-
- unlock_page(page);
- return ret;
-}
-
-STATIC unsigned int
-xfs_probe_unmapped_cluster(
- struct inode *inode,
- struct page *startpage,
- struct buffer_head *bh,
- struct buffer_head *head)
-{
- unsigned long tindex, tlast, tloff;
- unsigned int len, total = 0;
- struct address_space *mapping = inode->i_mapping;
-
- /* First sum forwards in this page */
- do {
- if (buffer_mapped(bh))
- break;
- total += bh->b_size;
- } while ((bh = bh->b_this_page) != head);
-
- /* If we reached the end of the page, sum forwards in
- * following pages.
- */
- if (bh == head) {
- tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
- /* Prune this back to avoid pathological behavior */
- tloff = min(tlast, startpage->index + 64);
- for (tindex = startpage->index + 1; tindex < tloff; tindex++) {
- len = xfs_probe_unmapped_page(mapping, tindex,
- PAGE_CACHE_SIZE);
- if (!len)
- return total;
- total += len;
- }
- if (tindex == tlast &&
- (tloff = i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
- total += xfs_probe_unmapped_page(mapping,
- tindex, tloff);
- }
- }
- return total;
-}
-
-/*
- * Probe for a given page (index) in the inode and test if it is delayed
- * and without unwritten buffers. Returns page locked and with an extra
- * reference count.
- */
-STATIC struct page *
-xfs_probe_delalloc_page(
- struct inode *inode,
- unsigned long index)
-{
- struct page *page;
-
- page = find_trylock_page(inode->i_mapping, index);
- if (!page)
- return NULL;
-
- if (page->mapping && page_has_buffers(page)) {
- struct buffer_head *bh, *head;
- int acceptable = 0;
-
- bh = head = page_buffers(page);
- do {
- if (buffer_unwritten(bh)) {
- acceptable = 0;
- break;
- } else if (buffer_delay(bh)) {
- acceptable = 1;
- }
- } while ((bh = bh->b_this_page) != head);
-
- if (acceptable)
- return page;
- }
-
- unlock_page(page);
- return NULL;
-}
-
-STATIC int
-xfs_map_unwritten(
- struct inode *inode,
- struct page *start_page,
- struct buffer_head *head,
- struct buffer_head *curr,
- unsigned long p_offset,
- int block_bits,
- xfs_iomap_t *iomapp,
- int startio,
- int all_bh)
-{
- struct buffer_head *bh = curr;
- xfs_iomap_t *tmp;
- page_buf_t *pb;
- loff_t offset, size;
- unsigned long nblocks = 0;
-
- offset = start_page->index;
- offset <<= PAGE_CACHE_SHIFT;
- offset += p_offset;
-
- /* get an "empty" pagebuf to manage IO completion
- * Proper values will be set before returning */
- pb = pagebuf_lookup(iomapp->iomap_target, 0, 0, 0);
- if (!pb)
- return -EAGAIN;
-
- /* Take a reference to the inode to prevent it from
- * being reclaimed while we have outstanding unwritten
- * extent IO on it.
- */
- if ((igrab(inode)) != inode) {
- pagebuf_free(pb);
- return -EAGAIN;
- }
-
- /* Set the count to 1 initially, this will stop an I/O
- * completion callout which happens before we have started
- * all the I/O from calling pagebuf_iodone too early.
- */
- atomic_set(&pb->pb_io_remaining, 1);
-
- /* First map forwards in the page consecutive buffers
- * covering this unwritten extent
- */
- do {
- if (!buffer_unwritten(bh))
- break;
- tmp = xfs_offset_to_map(start_page, iomapp, p_offset);
- if (!tmp)
- break;
- xfs_map_at_offset(start_page, bh, p_offset, block_bits, iomapp);
- set_buffer_unwritten_io(bh);
- bh->b_private = pb;
- p_offset += bh->b_size;
- nblocks++;
- } while ((bh = bh->b_this_page) != head);
-
- atomic_add(nblocks, &pb->pb_io_remaining);
-
- /* If we reached the end of the page, map forwards in any
- * following pages which are also covered by this extent.
- */
- if (bh == head) {
- struct address_space *mapping = inode->i_mapping;
- unsigned long tindex, tloff, tlast, bs;
- unsigned int bbits = inode->i_blkbits;
- struct page *page;
-
- tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
- tloff = (iomapp->iomap_offset + iomapp->iomap_bsize) >> PAGE_CACHE_SHIFT;
- tloff = min(tlast, tloff);
- for (tindex = start_page->index + 1; tindex < tloff; tindex++) {
- page = xfs_probe_unwritten_page(mapping,
- tindex, iomapp, pb,
- PAGE_CACHE_SIZE, &bs, bbits);
- if (!page)
- break;
- nblocks += bs;
- atomic_add(bs, &pb->pb_io_remaining);
- xfs_convert_page(inode, page, iomapp, pb,
- startio, all_bh);
- /* stop if converting the next page might add
- * enough blocks that the corresponding byte
- * count won't fit in our ulong page buf length */
- if (nblocks >= ((ULONG_MAX - PAGE_SIZE) >> block_bits))
- goto enough;
- }
-
- if (tindex == tlast &&
- (tloff = (i_size_read(inode) & (PAGE_CACHE_SIZE - 1)))) {
- page = xfs_probe_unwritten_page(mapping,
- tindex, iomapp, pb,
- tloff, &bs, bbits);
- if (page) {
- nblocks += bs;
- atomic_add(bs, &pb->pb_io_remaining);
- xfs_convert_page(inode, page, iomapp, pb,
- startio, all_bh);
- if (nblocks >= ((ULONG_MAX - PAGE_SIZE) >> block_bits))
- goto enough;
- }
- }
- }
-
-enough:
- size = nblocks; /* NB: using 64bit number here */
- size <<= block_bits; /* convert fsb's to byte range */
-
- XFS_BUF_DATAIO(pb);
- XFS_BUF_ASYNC(pb);
- XFS_BUF_SET_SIZE(pb, size);
- XFS_BUF_SET_COUNT(pb, size);
- XFS_BUF_SET_OFFSET(pb, offset);
- XFS_BUF_SET_FSPRIVATE(pb, LINVFS_GET_VP(inode));
- XFS_BUF_SET_IODONE_FUNC(pb, linvfs_unwritten_convert);
-
- if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
- pagebuf_iodone(pb, 1, 1);
- }
-
- return 0;
-}
-
-STATIC void
-xfs_submit_page(
- struct page *page,
- struct buffer_head *bh_arr[],
- int cnt)
-{
- struct buffer_head *bh;
- int i;
-
- if (cnt) {
- for (i = 0; i < cnt; i++) {
- bh = bh_arr[i];
- set_buffer_async_io(bh);
- if (buffer_unwritten(bh))
- set_buffer_unwritten_io(bh);
- set_buffer_uptodate(bh);
- clear_buffer_dirty(bh);
- }
-
- for (i = 0; i < cnt; i++) {
- refile_buffer(bh_arr[i]);
- submit_bh(WRITE, bh_arr[i]);
- }
- } else
- unlock_page(page);
-}
-
-/*
- * Allocate & map buffers for page given the extent map. Write it out.
- * except for the original page of a writepage, this is called on
- * delalloc/unwritten pages only, for the original page it is possible
- * that the page has no mapping at all.
- */
-STATIC void
-xfs_convert_page(
- struct inode *inode,
- struct page *page,
- xfs_iomap_t *iomapp,
- void *private,
- int startio,
- int all_bh)
-{
- struct buffer_head *bh_arr[MAX_BUF_PER_PAGE], *bh, *head;
- xfs_iomap_t *mp = iomapp, *tmp;
- unsigned long end, offset, end_index;
- int i = 0, index = 0;
- int bbits = inode->i_blkbits;
-
- end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
- if (page->index < end_index) {
- end = PAGE_CACHE_SIZE;
- } else {
- end = i_size_read(inode) & (PAGE_CACHE_SIZE-1);
- }
- bh = head = page_buffers(page);
- do {
- offset = i << bbits;
- if (!(PageUptodate(page) || buffer_uptodate(bh)))
- continue;
- if (buffer_mapped(bh) && all_bh &&
- !buffer_unwritten(bh) && !buffer_delay(bh)) {
- if (startio && (offset < end)) {
- lock_buffer(bh);
- bh_arr[index++] = bh;
- }
- continue;
- }
- tmp = xfs_offset_to_map(page, mp, offset);
- if (!tmp)
- continue;
- ASSERT(!(tmp->iomap_flags & IOMAP_HOLE));
- ASSERT(!(tmp->iomap_flags & IOMAP_DELAY));
-
- /* If this is a new unwritten extent buffer (i.e. one
- * that we haven't passed in private data for, we must
- * now map this buffer too.
- */
- if (buffer_unwritten(bh) && !bh->b_end_io) {
- ASSERT(tmp->iomap_flags & IOMAP_UNWRITTEN);
- xfs_map_unwritten(inode, page, head, bh,
- offset, bbits, tmp, startio, all_bh);
- } else if (! (buffer_unwritten(bh) && buffer_locked(bh))) {
- xfs_map_at_offset(page, bh, offset, bbits, tmp);
- if (buffer_unwritten(bh)) {
- set_buffer_unwritten_io(bh);
- bh->b_private = private;
- ASSERT(private);
- }
- }
- if (startio && (offset < end)) {
- bh_arr[index++] = bh;
- } else {
- unlock_buffer(bh);
- mark_buffer_dirty(bh);
- }
- } while (i++, (bh = bh->b_this_page) != head);
-
- if (startio) {
- xfs_submit_page(page, bh_arr, index);
- } else {
- unlock_page(page);
- }
-}
-
-/*
- * Convert & write out a cluster of pages in the same extent as defined
- * by mp and following the start page.
- */
-STATIC void
-xfs_cluster_write(
- struct inode *inode,
- unsigned long tindex,
- xfs_iomap_t *iomapp,
- int startio,
- int all_bh)
-{
- unsigned long tlast;
- struct page *page;
-
- tlast = (iomapp->iomap_offset + iomapp->iomap_bsize) >> PAGE_CACHE_SHIFT;
- for (; tindex < tlast; tindex++) {
- page = xfs_probe_delalloc_page(inode, tindex);
- if (!page)
- break;
- xfs_convert_page(inode, page, iomapp, NULL, startio, all_bh);
- }
-}
-
-/*
- * Calling this without startio set means we are being asked to make a dirty
- * page ready for freeing it's buffers. When called with startio set then
- * we are coming from writepage.
- *
- * When called with startio set it is important that we write the WHOLE
- * page if possible.
- * The bh->b_state's cannot know if any of the blocks or which block for
- * that matter are dirty due to mmap writes, and therefore bh uptodate is
- * only vaild if the page itself isn't completely uptodate. Some layers
- * may clear the page dirty flag prior to calling write page, under the
- * assumption the entire page will be written out; by not writing out the
- * whole page the page can be reused before all valid dirty data is
- * written out. Note: in the case of a page that has been dirty'd by
- * mapwrite and but partially setup by block_prepare_write the
- * bh->b_states's will not agree and only ones setup by BPW/BCW will have
- * valid state, thus the whole page must be written out thing.
- */
-
-STATIC int
-xfs_page_state_convert(
- struct inode *inode,
- struct page *page,
- int startio,
- int unmapped) /* also implies page uptodate */
-{
- struct buffer_head *bh_arr[MAX_BUF_PER_PAGE], *bh, *head;
- xfs_iomap_t *iomp, iomap;
- unsigned long p_offset = 0, end_index;
- loff_t offset;
- unsigned long long end_offset;
- int len, err, i, cnt = 0, uptodate = 1;
- int flags = startio ? 0 : BMAPI_TRYLOCK;
- int page_dirty = 1;
-
-
- /* Are we off the end of the file ? */
- end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
- if (page->index >= end_index) {
- if ((page->index >= end_index + 1) ||
- !(i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
- err = -EIO;
- goto error;
- }
- }
-
- offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
- end_offset = min_t(unsigned long long,
- offset + PAGE_CACHE_SIZE, i_size_read(inode));
-
- bh = head = page_buffers(page);
- iomp = NULL;
-
- len = bh->b_size;
- do {
- if (offset >= end_offset)
- break;
- if (!buffer_uptodate(bh))
- uptodate = 0;
- if (!(PageUptodate(page) || buffer_uptodate(bh)) && !startio)
- continue;
-
- if (iomp) {
- iomp = xfs_offset_to_map(page, &iomap, p_offset);
- }
-
- /*
- * First case, map an unwritten extent and prepare for
- * extent state conversion transaction on completion.
- */
- if (buffer_unwritten(bh)) {
- if (!iomp) {
- err = xfs_map_blocks(inode, offset, len, &iomap,
- BMAPI_READ|BMAPI_IGNSTATE);
- if (err) {
- goto error;
- }
- iomp = xfs_offset_to_map(page, &iomap,
- p_offset);
- }
- if (iomp && startio) {
- if (!bh->b_end_io) {
- err = xfs_map_unwritten(inode, page,
- head, bh, p_offset,
- inode->i_blkbits, iomp,
- startio, unmapped);
- if (err) {
- goto error;
- }
- }
- bh_arr[cnt++] = bh;
- page_dirty = 0;
- }
- /*
- * Second case, allocate space for a delalloc buffer.
- * We can return EAGAIN here in the release page case.
- */
- } else if (buffer_delay(bh)) {
- if (!iomp) {
- err = xfs_map_blocks(inode, offset, len, &iomap,
- BMAPI_ALLOCATE | flags);
- if (err) {
- goto error;
- }
- iomp = xfs_offset_to_map(page, &iomap,
- p_offset);
- }
- if (iomp) {
- xfs_map_at_offset(page, bh, p_offset,
- inode->i_blkbits, iomp);
- if (startio) {
- bh_arr[cnt++] = bh;
- } else {
- unlock_buffer(bh);
- mark_buffer_dirty(bh);
- }
- page_dirty = 0;
- }
- } else if ((buffer_uptodate(bh) || PageUptodate(page)) &&
- (unmapped || startio)) {
-
- if (!buffer_mapped(bh)) {
- int size;
-
- /*
- * Getting here implies an unmapped buffer
- * was found, and we are in a path where we
- * need to write the whole page out.
- */
- if (!iomp) {
- size = xfs_probe_unmapped_cluster(
- inode, page, bh, head);
- err = xfs_map_blocks(inode, offset,
- size, &iomap,
- BMAPI_WRITE|BMAPI_MMAP);
- if (err) {
- goto error;
- }
- iomp = xfs_offset_to_map(page, &iomap,
- p_offset);
- }
- if (iomp) {
- xfs_map_at_offset(page,
- bh, p_offset,
- inode->i_blkbits, iomp);
- if (startio) {
- bh_arr[cnt++] = bh;
- } else {
- unlock_buffer(bh);
- mark_buffer_dirty(bh);
- }
- page_dirty = 0;
- }
- } else if (startio) {
- if (buffer_uptodate(bh) &&
- !test_and_set_bit(BH_Lock, &bh->b_state)) {
- bh_arr[cnt++] = bh;
- page_dirty = 0;
- }
- }
- }
- } while (offset += len, p_offset += len,
- ((bh = bh->b_this_page) != head));
-
- if (uptodate && bh == head)
- SetPageUptodate(page);
-
- if (startio)
- xfs_submit_page(page, bh_arr, cnt);
-
- if (iomp)
- xfs_cluster_write(inode, page->index + 1, iomp, startio, unmapped);
-
- return page_dirty;
-
-error:
- for (i = 0; i < cnt; i++) {
- unlock_buffer(bh_arr[i]);
- }
-
- /*
- * If it's delalloc and we have nowhere to put it,
- * throw it away, unless the lower layers told
- * us to try again.
- */
- if (err != -EAGAIN) {
- if (!unmapped) {
- block_flushpage(page, 0);
- }
- ClearPageUptodate(page);
- }
- return err;
-}
-
-STATIC int
-linvfs_get_block_core(
- struct inode *inode,
- long iblock,
- struct buffer_head *bh_result,
- int create,
- int direct,
- bmapi_flags_t flags)
-{
- vnode_t *vp = LINVFS_GET_VP(inode);
- xfs_iomap_t iomap;
- int retpbbm = 1;
- int error;
- ssize_t size;
- loff_t offset = (loff_t)iblock << inode->i_blkbits;
-
- /* If we are doing writes at the end of the file,
- * allocate in chunks
- */
- if (create && (offset >= i_size_read(inode)) /* && !(flags & BMAPI_SYNC) */)
- size = 1 << XFS_WRITE_IO_LOG;
- else
- size = 1 << inode->i_blkbits;
-
- VOP_BMAP(vp, offset, size,
- create ? flags : BMAPI_READ, &iomap, &retpbbm, error);
- if (error)
- return -error;
-
- if (retpbbm == 0)
- return 0;
-
- if (iomap.iomap_bn != IOMAP_DADDR_NULL) {
- xfs_daddr_t bn;
- loff_t delta;
-
- /* For unwritten extents do not report a disk address on
- * the read case (treat as if we're reading into a hole).
- */
- if (create || !(iomap.iomap_flags & IOMAP_UNWRITTEN)) {
- delta = offset - iomap.iomap_offset;
- delta >>= inode->i_blkbits;
-
- bn = iomap.iomap_bn >> (inode->i_blkbits - BBSHIFT);
- bn += delta;
-
- bh_result->b_blocknr = bn;
- set_buffer_mapped(bh_result);
- }
- if (create && (iomap.iomap_flags & IOMAP_UNWRITTEN)) {
- set_buffer_unwritten(bh_result);
- set_buffer_delay(bh_result);
- }
- }
-
- /* If this is a realtime file, data might be on a new device */
- bh_result->b_dev = iomap.iomap_target->pbr_kdev;
-
- /* If we previously allocated a block out beyond eof and
- * we are now coming back to use it then we will need to
- * flag it as new even if it has a disk address.
- */
- if (create &&
- ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
- (offset >= i_size_read(inode)))) {
- set_buffer_new(bh_result);
- }
-
- if (iomap.iomap_flags & IOMAP_DELAY) {
- if (unlikely(direct))
- BUG();
- if (create) {
- set_buffer_mapped(bh_result);
- }
- set_buffer_delay(bh_result);
- }
-
- return 0;
-}
-
-int
-linvfs_get_block(
- struct inode *inode,
- long iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return linvfs_get_block_core(inode, iblock, bh_result,
- create, 0, BMAPI_WRITE);
-}
-
-STATIC int
-linvfs_get_block_sync(
- struct inode *inode,
- long iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return linvfs_get_block_core(inode, iblock, bh_result,
- create, 0, BMAPI_SYNC|BMAPI_WRITE);
-}
-
-STATIC int
-linvfs_get_block_direct(
- struct inode *inode,
- long iblock,
- struct buffer_head *bh_result,
- int create)
-{
- return linvfs_get_block_core(inode, iblock, bh_result,
- create, 1, BMAPI_WRITE|BMAPI_DIRECT);
-}
-
-STATIC int
-linvfs_bmap(
- struct address_space *mapping,
- long block)
-{
- struct inode *inode = (struct inode *)mapping->host;
- vnode_t *vp = LINVFS_GET_VP(inode);
- int error;
-
- vn_trace_entry(vp, "linvfs_bmap", (inst_t *)__return_address);
-
- VOP_RWLOCK(vp, VRWLOCK_READ);
- VOP_FLUSH_PAGES(vp, (xfs_off_t)0, -1, 0, FI_REMAPF, error);
- VOP_RWUNLOCK(vp, VRWLOCK_READ);
- return generic_block_bmap(mapping, block, linvfs_get_block_direct);
-}
-
-STATIC int
-linvfs_readpage(
- struct file *unused,
- struct page *page)
-{
- return block_read_full_page(page, linvfs_get_block);
-}
-
-STATIC void
-xfs_count_page_state(
- struct page *page,
- int *delalloc,
- int *unmapped,
- int *unwritten)
-{
- struct buffer_head *bh, *head;
-
- *delalloc = *unmapped = *unwritten = 0;
-
- bh = head = page_buffers(page);
- do {
- if (buffer_uptodate(bh) && !buffer_mapped(bh))
- (*unmapped) = 1;
- else if (buffer_unwritten(bh) && !buffer_delay(bh))
- clear_buffer_unwritten(bh);
- else if (buffer_unwritten(bh))
- (*unwritten) = 1;
- else if (buffer_delay(bh))
- (*delalloc) = 1;
- } while ((bh = bh->b_this_page) != head);
-}
-
-
-/*
- * writepage: Called from one of two places:
- *
- * 1. we are flushing a delalloc buffer head.
- *
- * 2. we are writing out a dirty page. Typically the page dirty
- * state is cleared before we get here. In this case is it
- * conceivable we have no buffer heads.
- *
- * For delalloc space on the page we need to allocate space and
- * flush it. For unmapped buffer heads on the page we should
- * allocate space if the page is uptodate. For any other dirty
- * buffer heads on the page we should flush them.
- *
- * If we detect that a transaction would be required to flush
- * the page, we have to check the process flags first, if we
- * are already in a transaction or disk I/O during allocations
- * is off, we need to fail the writepage and redirty the page.
- */
-
-STATIC int
-linvfs_writepage(
- struct page *page)
-{
- int error;
- int need_trans;
- int delalloc, unmapped, unwritten;
- struct inode *inode = page->mapping->host;
- xfs_pflags_t pflags;
-
- xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
-
- /*
- * We need a transaction if:
- * 1. There are delalloc buffers on the page
- * 2. The page is uptodate and we have unmapped buffers
- * 3. The page is uptodate and we have no buffers
- * 4. There are unwritten buffers on the page
- */
-
- if (!page_has_buffers(page)) {
- unmapped = 1;
- need_trans = 1;
- } else {
- xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
- if (!PageUptodate(page))
- unmapped = 0;
- need_trans = delalloc + unmapped + unwritten;
- }
-
- /*
- * If we need a transaction and the process flags say
- * we are already in a transaction, or no IO is allowed
- * then mark the page dirty again and leave the page
- * as is.
- */
-
- if ((PFLAGS_TEST_FSTRANS() || PFLAGS_TEST_NOIO()) && need_trans)
- goto out_fail;
-
- /*
- * Delay hooking up buffer heads until we have
- * made our go/no-go decision.
- */
- if (!page_has_buffers(page))
- create_empty_buffers(page, inode->i_dev, 1 << inode->i_blkbits);
-
- /*
- * Convert delayed allocate, unwritten or unmapped space
- * to real space and flush out to disk.
- */
- if (need_trans)
- PFLAGS_SET_NOIO(&pflags);
- error = xfs_page_state_convert(inode, page, 1, unmapped);
- if (need_trans)
- PFLAGS_RESTORE(&pflags);
- if (error == -EAGAIN)
- goto out_fail;
-
- if (unlikely(error < 0)) {
- unlock_page(page);
- return error;
- }
-
- return 0;
-
-out_fail:
- SetPageDirty(page);
- unlock_page(page);
- return 0;
-}
-
-/*
- * Called to move a page into cleanable state - and from there
- * to be released. Possibly the page is already clean. We always
- * have buffer heads in this call.
- *
- * Returns 0 if the page is ok to release, 1 otherwise.
- *
- * Possible scenarios are:
- *
- * 1. We are being called to release a page which has been written
- * to via regular I/O. buffer heads will be dirty and possibly
- * delalloc. If no delalloc buffer heads in this case then we
- * can just return zero.
- *
- * 2. We are called to release a page which has been written via
- * mmap, all we need to do is ensure there is no delalloc
- * state in the buffer heads, if not we can let the caller
- * free them and we should come back later via writepage.
- */
-STATIC int
-linvfs_release_page(
- struct page *page,
- int gfp_mask)
-{
- struct inode *inode = page->mapping->host;
- int dirty, delalloc, unmapped, unwritten;
-
- xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
-
- xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
- if (!delalloc && !unwritten)
- return 1;
-
- if (!(gfp_mask & __GFP_FS))
- return 0;
-
- /* If we are already inside a transaction or the thread cannot
- * do I/O, we cannot release this page.
- */
- if (PFLAGS_TEST_FSTRANS() || PFLAGS_TEST_NOIO())
- return 0;
-
- /*
- * Convert delalloc space to real space, do not flush the
- * data out to disk, that will be done by the caller.
- * Never need to allocate space here - we will always
- * come back to writepage in that case.
- */
- dirty = xfs_page_state_convert(inode, page, 0, 0);
- return (dirty == 0 && !unwritten) ? 1 : 0;
-}
-
-STATIC int
-linvfs_prepare_write(
- struct file *file,
- struct page *page,
- unsigned int from,
- unsigned int to)
-{
- if (file && (file->f_flags & O_SYNC)) {
- return block_prepare_write(page, from, to,
- linvfs_get_block_sync);
- } else {
- return block_prepare_write(page, from, to,
- linvfs_get_block);
- }
-}
-
-/*
- * Initiate I/O on a kiobuf of user memory
- */
-STATIC int
-linvfs_direct_IO(
- int rw,
- struct inode *inode,
- struct kiobuf *iobuf,
- unsigned long blocknr,
- int blocksize)
-{
- struct page **maplist;
- size_t page_offset;
- page_buf_t *pb;
- xfs_iomap_t iomap;
- int error = 0;
- int pb_flags, map_flags, pg_index = 0;
- size_t length, total;
- loff_t offset, map_size;
- size_t size;
- vnode_t *vp = LINVFS_GET_VP(inode);
-
- /* Note - although the iomap could have a 64-bit size,
- * kiobuf->length is only an int, so the min(map_size, length)
- * test will keep us from overflowing the pagebuf size_t size.
- */
- total = length = iobuf->length;
- offset = blocknr;
- offset <<= inode->i_blkbits;
-
- maplist = iobuf->maplist;
- page_offset = iobuf->offset;
-
- map_flags = (rw ? BMAPI_WRITE : BMAPI_READ) | BMAPI_DIRECT;
- pb_flags = (rw ? PBF_WRITE : PBF_READ) | PBF_FORCEIO | PBF_DIRECTIO;
- while (length) {
- error = xfs_map_blocks(inode, offset, length, &iomap, map_flags);
- if (error)
- break;
- BUG_ON(iomap.iomap_flags & IOMAP_DELAY);
-
- map_size = iomap.iomap_bsize - iomap.iomap_delta;
- size = (size_t)min(map_size, (loff_t)length);
-
- if ((iomap.iomap_flags & IOMAP_HOLE) ||
- ((iomap.iomap_flags & IOMAP_UNWRITTEN) && rw == READ)) {
- size_t zero_len = size;
-
- if (rw == WRITE)
- break;
-
- /* Need to zero it all */
- while (zero_len) {
- struct page *page;
- size_t pg_len;
-
- pg_len = min((size_t)
- (PAGE_CACHE_SIZE - page_offset),
- zero_len);
-
- page = maplist[pg_index];
-
- memset(kmap(page) + page_offset, 0, pg_len);
- flush_dcache_page(page);
- kunmap(page);
-
- zero_len -= pg_len;
- if ((pg_len + page_offset) == PAGE_CACHE_SIZE) {
- pg_index++;
- page_offset = 0;
- } else {
- page_offset = (page_offset + pg_len) &
- ~PAGE_CACHE_MASK;
- }
- }
- } else {
- int pg_count;
-
- pg_count = (size + page_offset + PAGE_CACHE_SIZE - 1)
- >> PAGE_CACHE_SHIFT;
- if ((pb = pagebuf_lookup(iomap.iomap_target, offset,
- size, pb_flags)) == NULL) {
- error = -ENOMEM;
- break;
- }
- /* Need to hook up pagebuf to kiobuf pages */
- pb->pb_pages = &maplist[pg_index];
- pb->pb_offset = page_offset;
- pb->pb_page_count = pg_count;
- pb->pb_bn = iomap.iomap_bn + (iomap.iomap_delta >> BBSHIFT);
-
- error = pagebuf_iostart(pb, pb_flags);
- if (!error && (iomap.iomap_flags & IOMAP_UNWRITTEN)) {
- VOP_BMAP(vp, XFS_BUF_OFFSET(pb),
- XFS_BUF_SIZE(pb),
- BMAPI_UNWRITTEN, NULL, NULL, error);
- }
-
- pagebuf_rele(pb);
-
- if (error) {
- if (error > 0)
- error = -error;
- break;
- }
-
- page_offset = (page_offset + size) & ~PAGE_CACHE_MASK;
- if (page_offset)
- pg_count--;
- pg_index += pg_count;
- }
-
- offset += size;
- length -= size;
- }
-
- return (error ? error : (int)(total - length));
-}
-
-
-struct address_space_operations linvfs_aops = {
- .readpage = linvfs_readpage,
- .writepage = linvfs_writepage,
- .sync_page = block_sync_page,
- .releasepage = linvfs_release_page,
- .prepare_write = linvfs_prepare_write,
- .commit_write = generic_commit_write,
- .bmap = linvfs_bmap,
- .direct_IO = linvfs_direct_IO,
-};
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)