--- /dev/null
+/*
+ * 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/mpage.h>
+#include <linux/writeback.h>
+
+STATIC void xfs_count_page_state(struct page *, int *, int *, int *);
+STATIC void xfs_convert_page(struct inode *, struct page *, xfs_iomap_t *,
+ struct writeback_control *wbc, 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)
+{
+ xfs_buf_t *pb = (xfs_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_async_write(bh, uptodate);
+}
+
+/*
+ * Issue transactions to convert a buffer range from unwritten
+ * to written extents (buffered IO).
+ */
+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);
+}
+
+/*
+ * Issue transactions to convert a buffer range from unwritten
+ * to written extents (direct IO).
+ */
+STATIC void
+linvfs_unwritten_convert_direct(
+ struct inode *inode,
+ loff_t offset,
+ ssize_t size,
+ void *private)
+{
+ ASSERT(!private || inode == (struct inode *)private);
+
+ /* private indicates an unwritten extent lay beneath this IO,
+ * see linvfs_get_block_core.
+ */
+ if (private && size > 0) {
+ vnode_t *vp = LINVFS_GET_VP(inode);
+ int error;
+
+ VOP_BMAP(vp, offset, size, BMAPI_UNWRITTEN, NULL, NULL, error);
+ }
+}
+
+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 -1) >= 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_bdev = iomapp->iomap_target->pbr_bdev;
+ 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,
+ pgoff_t index,
+ xfs_iomap_t *iomapp,
+ xfs_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 (PageWriteback(page))
+ goto out;
+
+ 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;
+ }
+
+out:
+ 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,
+ pgoff_t index,
+ unsigned int pg_offset)
+{
+ struct page *page;
+ int ret = 0;
+
+ page = find_trylock_page(mapping, index);
+ if (!page)
+ return 0;
+ if (PageWriteback(page))
+ goto out;
+
+ 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;
+ }
+
+out:
+ 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)
+{
+ pgoff_t tindex, tlast, tloff;
+ unsigned int pg_offset, 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 &&
+ (pg_offset = i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
+ total += xfs_probe_unmapped_page(mapping,
+ tindex, pg_offset);
+ }
+ }
+ 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,
+ pgoff_t index)
+{
+ struct page *page;
+
+ page = find_trylock_page(inode->i_mapping, index);
+ if (!page)
+ return NULL;
+ if (PageWriteback(page))
+ goto out;
+
+ 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;
+ }
+
+out:
+ 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,
+ struct writeback_control *wbc,
+ int startio,
+ int all_bh)
+{
+ struct buffer_head *bh = curr;
+ xfs_iomap_t *tmp;
+ xfs_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;
+ pgoff_t tindex, tloff, tlast;
+ unsigned long bs;
+ unsigned int pg_offset, 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, wbc, 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 &&
+ (pg_offset = (i_size_read(inode) & (PAGE_CACHE_SIZE - 1)))) {
+ page = xfs_probe_unwritten_page(mapping,
+ tindex, iomapp, pb,
+ pg_offset, &bs, bbits);
+ if (page) {
+ nblocks += bs;
+ atomic_add(bs, &pb->pb_io_remaining);
+ xfs_convert_page(inode, page, iomapp, wbc, 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;
+
+ BUG_ON(PageWriteback(page));
+ set_page_writeback(page);
+ clear_page_dirty(page);
+ unlock_page(page);
+
+ if (cnt) {
+ for (i = 0; i < cnt; i++) {
+ bh = bh_arr[i];
+ mark_buffer_async_write(bh);
+ if (buffer_unwritten(bh))
+ set_buffer_unwritten_io(bh);
+ set_buffer_uptodate(bh);
+ clear_buffer_dirty(bh);
+ }
+
+ for (i = 0; i < cnt; i++)
+ submit_bh(WRITE, bh_arr[i]);
+ } else
+ end_page_writeback(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,
+ struct writeback_control *wbc,
+ 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;
+ pgoff_t 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, wbc, 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 {
+ set_buffer_dirty(bh);
+ unlock_buffer(bh);
+ mark_buffer_dirty(bh);
+ }
+ } while (i++, (bh = bh->b_this_page) != head);
+
+ if (startio) {
+ wbc->nr_to_write--;
+ 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,
+ pgoff_t tindex,
+ xfs_iomap_t *iomapp,
+ struct writeback_control *wbc,
+ int startio,
+ int all_bh)
+{
+ pgoff_t 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, wbc, 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,
+ struct writeback_control *wbc,
+ 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;
+ pgoff_t 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,
+ wbc, 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 {
+ set_buffer_dirty(bh);
+ 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 {
+ set_buffer_dirty(bh);
+ 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, wbc,
+ 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_invalidatepage(page, 0);
+ }
+ ClearPageUptodate(page);
+ }
+ return err;
+}
+
+STATIC int
+linvfs_get_block_core(
+ struct inode *inode,
+ sector_t iblock,
+ unsigned long blocks,
+ 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 (blocks)
+ size = blocks << inode->i_blkbits;
+ 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;
+ bh_result->b_bdev = iomap.iomap_target->pbr_bdev;
+ set_buffer_mapped(bh_result);
+ }
+ if (create && (iomap.iomap_flags & IOMAP_UNWRITTEN)) {
+ if (direct)
+ bh_result->b_private = inode;
+ 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_bdev = iomap.iomap_target->pbr_bdev;
+
+ /* 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)) || (iomap.iomap_flags & IOMAP_NEW))) {
+ set_buffer_new(bh_result);
+ }
+
+ if (iomap.iomap_flags & IOMAP_DELAY) {
+ if (unlikely(direct))
+ BUG();
+ if (create) {
+ set_buffer_mapped(bh_result);
+ set_buffer_uptodate(bh_result);
+ }
+ bh_result->b_bdev = iomap.iomap_target->pbr_bdev;
+ set_buffer_delay(bh_result);
+ }
+
+ if (blocks) {
+ loff_t iosize;
+ iosize = (iomap.iomap_bsize - iomap.iomap_delta);
+ bh_result->b_size =
+ (ssize_t)min(iosize, (loff_t)(blocks << inode->i_blkbits));
+ }
+
+ return 0;
+}
+
+int
+linvfs_get_block(
+ struct inode *inode,
+ sector_t iblock,
+ struct buffer_head *bh_result,
+ int create)
+{
+ return linvfs_get_block_core(inode, iblock, 0, bh_result,
+ create, 0, BMAPI_WRITE);
+}
+
+STATIC int
+linvfs_get_block_sync(
+ struct inode *inode,
+ sector_t iblock,
+ struct buffer_head *bh_result,
+ int create)
+{
+ return linvfs_get_block_core(inode, iblock, 0, bh_result,
+ create, 0, BMAPI_SYNC|BMAPI_WRITE);
+}
+
+STATIC int
+linvfs_get_blocks_direct(
+ struct inode *inode,
+ sector_t iblock,
+ unsigned long max_blocks,
+ struct buffer_head *bh_result,
+ int create)
+{
+ return linvfs_get_block_core(inode, iblock, max_blocks, bh_result,
+ create, 1, BMAPI_WRITE|BMAPI_DIRECT);
+}
+
+STATIC ssize_t
+linvfs_direct_IO(
+ int rw,
+ struct kiocb *iocb,
+ const struct iovec *iov,
+ loff_t offset,
+ unsigned long nr_segs)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ vnode_t *vp = LINVFS_GET_VP(inode);
+ xfs_iomap_t iomap;
+ int maps = 1;
+ int error;
+
+ VOP_BMAP(vp, offset, 0, BMAPI_DEVICE, &iomap, &maps, error);
+ if (error)
+ return -error;
+
+ return blockdev_direct_IO_no_locking(rw, iocb, inode,
+ iomap.iomap_target->pbr_bdev,
+ iov, offset, nr_segs,
+ linvfs_get_blocks_direct,
+ linvfs_unwritten_convert_direct);
+}
+
+
+STATIC sector_t
+linvfs_bmap(
+ struct address_space *mapping,
+ sector_t 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);
+}
+
+STATIC int
+linvfs_readpage(
+ struct file *unused,
+ struct page *page)
+{
+ return mpage_readpage(page, linvfs_get_block);
+}
+
+STATIC int
+linvfs_readpages(
+ struct file *unused,
+ struct address_space *mapping,
+ struct list_head *pages,
+ unsigned nr_pages)
+{
+ return mpage_readpages(mapping, pages, nr_pages, 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,
+ struct writeback_control *wbc)
+{
+ int error;
+ int need_trans;
+ int delalloc, unmapped, unwritten;
+ struct inode *inode = page->mapping->host;
+
+ 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() && 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, 1 << inode->i_blkbits, 0);
+
+ /*
+ * Convert delayed allocate, unwritten or unmapped space
+ * to real space and flush out to disk.
+ */
+ error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
+ if (error == -EAGAIN)
+ goto out_fail;
+ if (unlikely(error < 0))
+ goto out_unlock;
+
+ return 0;
+
+out_fail:
+ set_page_dirty(page);
+ unlock_page(page);
+ return 0;
+out_unlock:
+ unlock_page(page);
+ return error;
+}
+
+/*
+ * 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;
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ .nr_to_write = 1,
+ };
+
+ xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
+
+ xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
+ if (!delalloc && !unwritten)
+ goto free_buffers;
+
+ 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())
+ 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, &wbc, 0, 0);
+ if (dirty == 0 && !unwritten)
+ goto free_buffers;
+ return 0;
+
+free_buffers:
+ return try_to_free_buffers(page);
+}
+
+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);
+ }
+}
+
+struct address_space_operations linvfs_aops = {
+ .readpage = linvfs_readpage,
+ .readpages = linvfs_readpages,
+ .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,
+};
git://git.onelab.eu / linux-2.6.git / blobdiff