diff options
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_aops.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_aops.c | 1275 |
1 files changed, 1275 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c new file mode 100644 index 0000000..76a8475 --- /dev/null +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -0,0 +1,1275 @@ +/* + * Copyright (c) 2000-2005 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 = (loff_t)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 */ + 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 *mapp, + int flags) +{ + vnode_t *vp = LINVFS_GET_VP(inode); + int error, nmaps = 1; + + VOP_BMAP(vp, offset, count, flags, mapp, &nmaps, error); + if (!error && (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; + BUG_ON(!bn && !(iomapp->iomap_flags & IOMAP_REALTIME)); + 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 NULL; + 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) || !buffer_uptodate(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 writeback_control *wbc, + struct buffer_head *bh_arr[], + int bh_count, + int probed_page, + int clear_dirty) +{ + struct buffer_head *bh; + int i; + + BUG_ON(PageWriteback(page)); + set_page_writeback(page); + if (clear_dirty) + clear_page_dirty(page); + unlock_page(page); + + if (bh_count) { + for (i = 0; i < bh_count; 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 < bh_count; i++) + submit_bh(WRITE, bh_arr[i]); + + if (probed_page && clear_dirty) + wbc->nr_to_write--; /* Wrote an "extra" page */ + } else { + end_page_writeback(page); + wbc->pages_skipped++; /* We didn't write this 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 (offset >= end) + break; + if (!(PageUptodate(page) || buffer_uptodate(bh))) + continue; + if (buffer_mapped(bh) && all_bh && + !(buffer_unwritten(bh) || buffer_delay(bh))) { + if (startio) { + 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) { + 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) { + xfs_submit_page(page, wbc, bh_arr, index, 1, index == i); + } 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; + + 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; + loff_t offset; + unsigned long p_offset = 0; + __uint64_t end_offset; + pgoff_t end_index, last_index, tlast; + int len, err, i, cnt = 0, uptodate = 1; + int flags = startio ? 0 : BMAPI_TRYLOCK; + int page_dirty, delalloc = 0; + + /* Is this page beyond the end of the file? */ + offset = i_size_read(inode); + end_index = offset >> PAGE_CACHE_SHIFT; + last_index = (offset - 1) >> 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; + + /* + * page_dirty is initially a count of buffers on the page and + * is decrememted as we move each into a cleanable state. + */ + len = bh->b_size; + page_dirty = PAGE_CACHE_SIZE / len; + + 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 (!startio) + continue; + 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) { + 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; + } + } else { + set_bit(BH_Lock, &bh->b_state); + } + BUG_ON(!buffer_locked(bh)); + bh_arr[cnt++] = bh; + page_dirty--; + } + /* + * 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) { + delalloc = 1; + 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--; + } + } 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--; + } + } else if (startio) { + if (buffer_uptodate(bh) && + !test_and_set_bit(BH_Lock, &bh->b_state)) { + bh_arr[cnt++] = bh; + page_dirty--; + } + } + } + } while (offset += len, p_offset += len, + ((bh = bh->b_this_page) != head)); + + if (uptodate && bh == head) + SetPageUptodate(page); + + if (startio) + xfs_submit_page(page, wbc, bh_arr, cnt, 0, 1); + + if (iomp) { + tlast = (iomp->iomap_offset + iomp->iomap_bsize - 1) >> + PAGE_CACHE_SHIFT; + if (delalloc && (tlast > last_index)) + tlast = last_index; + xfs_cluster_write(inode, page->index + 1, iomp, wbc, + startio, unmapped, tlast); + } + + 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( + 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; + BUG_ON(!bn && !(iomap.iomap_flags & IOMAP_REALTIME)); + bh_result->b_blocknr = bn; + 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) { + BUG_ON(direct); + if (create) { + set_buffer_uptodate(bh_result); + set_buffer_mapped(bh_result); + set_buffer_delay(bh_result); + } + } + + if (blocks) { + bh_result->b_size = (ssize_t)min( + (loff_t)(iomap.iomap_bsize - iomap.iomap_delta), + (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(inode, iblock, 0, bh_result, + create, 0, 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(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_own_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: + redirty_page_for_writepage(wbc, 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) +{ + 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, +}; |
