/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * Copyright (C) 2002, 2004 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include #include #include #include #include #include #define MLOG_MASK_PREFIX ML_FILE_IO #include #include "ocfs2.h" #include "alloc.h" #include "aops.h" #include "dlmglue.h" #include "extent_map.h" #include "file.h" #include "inode.h" #include "journal.h" #include "suballoc.h" #include "super.h" #include "symlink.h" #include "buffer_head_io.h" static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { int err = -EIO; int status; struct ocfs2_dinode *fe = NULL; struct buffer_head *bh = NULL; struct buffer_head *buffer_cache_bh = NULL; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); void *kaddr; mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, (unsigned long long)iblock, bh_result, create); BUG_ON(ocfs2_inode_is_fast_symlink(inode)); if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) { mlog(ML_ERROR, "block offset > PATH_MAX: %llu", (unsigned long long)iblock); goto bail; } status = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno, &bh, OCFS2_BH_CACHED, inode); if (status < 0) { mlog_errno(status); goto bail; } fe = (struct ocfs2_dinode *) bh->b_data; if (!OCFS2_IS_VALID_DINODE(fe)) { mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n", (unsigned long long)fe->i_blkno, 7, fe->i_signature); goto bail; } if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb, le32_to_cpu(fe->i_clusters))) { mlog(ML_ERROR, "block offset is outside the allocated size: " "%llu\n", (unsigned long long)iblock); goto bail; } /* We don't use the page cache to create symlink data, so if * need be, copy it over from the buffer cache. */ if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) { u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock; buffer_cache_bh = sb_getblk(osb->sb, blkno); if (!buffer_cache_bh) { mlog(ML_ERROR, "couldn't getblock for symlink!\n"); goto bail; } /* we haven't locked out transactions, so a commit * could've happened. Since we've got a reference on * the bh, even if it commits while we're doing the * copy, the data is still good. */ if (buffer_jbd(buffer_cache_bh) && ocfs2_inode_is_new(inode)) { kaddr = kmap_atomic(bh_result->b_page, KM_USER0); if (!kaddr) { mlog(ML_ERROR, "couldn't kmap!\n"); goto bail; } memcpy(kaddr + (bh_result->b_size * iblock), buffer_cache_bh->b_data, bh_result->b_size); kunmap_atomic(kaddr, KM_USER0); set_buffer_uptodate(bh_result); } brelse(buffer_cache_bh); } map_bh(bh_result, inode->i_sb, le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock); err = 0; bail: if (bh) brelse(bh); mlog_exit(err); return err; } static int ocfs2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { int err = 0; unsigned int ext_flags; u64 p_blkno, past_eof; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode, (unsigned long long)iblock, bh_result, create); if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n", inode, inode->i_ino); if (S_ISLNK(inode->i_mode)) { /* this always does I/O for some reason. */ err = ocfs2_symlink_get_block(inode, iblock, bh_result, create); goto bail; } err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL, &ext_flags); if (err) { mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, " "%llu, NULL)\n", err, inode, (unsigned long long)iblock, (unsigned long long)p_blkno); goto bail; } /* * ocfs2 never allocates in this function - the only time we * need to use BH_New is when we're extending i_size on a file * system which doesn't support holes, in which case BH_New * allows block_prepare_write() to zero. */ mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb), "ino %lu, iblock %llu\n", inode->i_ino, (unsigned long long)iblock); /* Treat the unwritten extent as a hole for zeroing purposes. */ if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) map_bh(bh_result, inode->i_sb, p_blkno); if (!ocfs2_sparse_alloc(osb)) { if (p_blkno == 0) { err = -EIO; mlog(ML_ERROR, "iblock = %llu p_blkno = %llu blkno=(%llu)\n", (unsigned long long)iblock, (unsigned long long)p_blkno, (unsigned long long)OCFS2_I(inode)->ip_blkno); mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters); dump_stack(); } past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino, (unsigned long long)past_eof); if (create && (iblock >= past_eof)) set_buffer_new(bh_result); } bail: if (err < 0) err = -EIO; mlog_exit(err); return err; } static int ocfs2_readpage(struct file *file, struct page *page) { struct inode *inode = page->mapping->host; loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT; int ret, unlock = 1; mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0)); ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page); if (ret != 0) { if (ret == AOP_TRUNCATED_PAGE) unlock = 0; mlog_errno(ret); goto out; } down_read(&OCFS2_I(inode)->ip_alloc_sem); /* * i_size might have just been updated as we grabed the meta lock. We * might now be discovering a truncate that hit on another node. * block_read_full_page->get_block freaks out if it is asked to read * beyond the end of a file, so we check here. Callers * (generic_file_read, fault->nopage) are clever enough to check i_size * and notice that the page they just read isn't needed. * * XXX sys_readahead() seems to get that wrong? */ if (start >= i_size_read(inode)) { char *addr = kmap(page); memset(addr, 0, PAGE_SIZE); flush_dcache_page(page); kunmap(page); SetPageUptodate(page); ret = 0; goto out_alloc; } ret = ocfs2_data_lock_with_page(inode, 0, page); if (ret != 0) { if (ret == AOP_TRUNCATED_PAGE) unlock = 0; mlog_errno(ret); goto out_alloc; } ret = block_read_full_page(page, ocfs2_get_block); unlock = 0; ocfs2_data_unlock(inode, 0); out_alloc: up_read(&OCFS2_I(inode)->ip_alloc_sem); ocfs2_meta_unlock(inode, 0); out: if (unlock) unlock_page(page); mlog_exit(ret); return ret; } /* Note: Because we don't support holes, our allocation has * already happened (allocation writes zeros to the file data) * so we don't have to worry about ordered writes in * ocfs2_writepage. * * ->writepage is called during the process of invalidating the page cache * during blocked lock processing. It can't block on any cluster locks * to during block mapping. It's relying on the fact that the block * mapping can't have disappeared under the dirty pages that it is * being asked to write back. */ static int ocfs2_writepage(struct page *page, struct writeback_control *wbc) { int ret; mlog_entry("(0x%p)\n", page); ret = block_write_full_page(page, ocfs2_get_block, wbc); mlog_exit(ret); return ret; } /* * This is called from ocfs2_write_zero_page() which has handled it's * own cluster locking and has ensured allocation exists for those * blocks to be written. */ int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, unsigned from, unsigned to) { int ret; down_read(&OCFS2_I(inode)->ip_alloc_sem); ret = block_prepare_write(page, from, to, ocfs2_get_block); up_read(&OCFS2_I(inode)->ip_alloc_sem); return ret; } /* Taken from ext3. We don't necessarily need the full blown * functionality yet, but IMHO it's better to cut and paste the whole * thing so we can avoid introducing our own bugs (and easily pick up * their fixes when they happen) --Mark */ int walk_page_buffers( handle_t *handle, struct buffer_head *head, unsigned from, unsigned to, int *partial, int (*fn)( handle_t *handle, struct buffer_head *bh)) { struct buffer_head *bh; unsigned block_start, block_end; unsigned blocksize = head->b_size; int err, ret = 0; struct buffer_head *next; for ( bh = head, block_start = 0; ret == 0 && (bh != head || !block_start); block_start = block_end, bh = next) { next = bh->b_this_page; block_end = block_start + blocksize; if (block_end <= from || block_start >= to) { if (partial && !buffer_uptodate(bh)) *partial = 1; continue; } err = (*fn)(handle, bh); if (!ret) ret = err; } return ret; } handle_t *ocfs2_start_walk_page_trans(struct inode *inode, struct page *page, unsigned from, unsigned to) { struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); handle_t *handle = NULL; int ret = 0; handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); if (!handle) { ret = -ENOMEM; mlog_errno(ret); goto out; } if (ocfs2_should_order_data(inode)) { ret = walk_page_buffers(handle, page_buffers(page), from, to, NULL, ocfs2_journal_dirty_data); if (ret < 0) mlog_errno(ret); } out: if (ret) { if (handle) ocfs2_commit_trans(osb, handle); handle = ERR_PTR(ret); } return handle; } static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block) { sector_t status; u64 p_blkno = 0; int err = 0; struct inode *inode = mapping->host; mlog_entry("(block = %llu)\n", (unsigned long long)block); /* We don't need to lock journal system files, since they aren't * accessed concurrently from multiple nodes. */ if (!INODE_JOURNAL(inode)) { err = ocfs2_meta_lock(inode, NULL, 0); if (err) { if (err != -ENOENT) mlog_errno(err); goto bail; } down_read(&OCFS2_I(inode)->ip_alloc_sem); } err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL); if (!INODE_JOURNAL(inode)) { up_read(&OCFS2_I(inode)->ip_alloc_sem); ocfs2_meta_unlock(inode, 0); } if (err) { mlog(ML_ERROR, "get_blocks() failed, block = %llu\n", (unsigned long long)block); mlog_errno(err); goto bail; } bail: status = err ? 0 : p_blkno; mlog_exit((int)status); return status; } /* * TODO: Make this into a generic get_blocks function. * * From do_direct_io in direct-io.c: * "So what we do is to permit the ->get_blocks function to populate * bh.b_size with the size of IO which is permitted at this offset and * this i_blkbits." * * This function is called directly from get_more_blocks in direct-io.c. * * called like this: dio->get_blocks(dio->inode, fs_startblk, * fs_count, map_bh, dio->rw == WRITE); */ static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { int ret; u64 p_blkno, inode_blocks, contig_blocks; unsigned int ext_flags; unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits; unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits; /* This function won't even be called if the request isn't all * nicely aligned and of the right size, so there's no need * for us to check any of that. */ inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode)); /* * Any write past EOF is not allowed because we'd be extending. */ if (create && (iblock + max_blocks) > inode_blocks) { ret = -EIO; goto bail; } /* This figures out the size of the next contiguous block, and * our logical offset */ ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, &contig_blocks, &ext_flags); if (ret) { mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n", (unsigned long long)iblock); ret = -EIO; goto bail; } if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) { ocfs2_error(inode->i_sb, "Inode %llu has a hole at block %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno, (unsigned long long)iblock); ret = -EROFS; goto bail; } /* * get_more_blocks() expects us to describe a hole by clearing * the mapped bit on bh_result(). * * Consider an unwritten extent as a hole. */ if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN)) map_bh(bh_result, inode->i_sb, p_blkno); else { /* * ocfs2_prepare_inode_for_write() should have caught * the case where we'd be filling a hole and triggered * a buffered write instead. */ if (create) { ret = -EIO; mlog_errno(ret); goto bail; } clear_buffer_mapped(bh_result); } /* make sure we don't map more than max_blocks blocks here as that's all the kernel will handle at this point. */ if (max_blocks < contig_blocks) contig_blocks = max_blocks; bh_result->b_size = contig_blocks << blocksize_bits; bail: return ret; } /* * ocfs2_dio_end_io is called by the dio core when a dio is finished. We're * particularly interested in the aio/dio case. Like the core uses * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from * truncation on another. */ static void ocfs2_dio_end_io(struct kiocb *iocb, loff_t offset, ssize_t bytes, void *private) { struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; /* this io's submitter should not have unlocked this before we could */ BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); ocfs2_iocb_clear_rw_locked(iocb); up_read(&inode->i_alloc_sem); ocfs2_rw_unlock(inode, 0); } /* * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen * from ext3. PageChecked() bits have been removed as OCFS2 does not * do journalled data. */ static void ocfs2_invalidatepage(struct page *page, unsigned long offset) { journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; journal_invalidatepage(journal, page, offset); } static int ocfs2_releasepage(struct page *page, gfp_t wait) { journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal; if (!page_has_buffers(page)) return 0; return journal_try_to_free_buffers(journal, page, wait); } static ssize_t ocfs2_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_path.dentry->d_inode->i_mapping->host; int ret; mlog_entry_void(); if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) { /* * We get PR data locks even for O_DIRECT. This * allows concurrent O_DIRECT I/O but doesn't let * O_DIRECT with extending and buffered zeroing writes * race. If they did race then the buffered zeroing * could be written back after the O_DIRECT I/O. It's * one thing to tell people not to mix buffered and * O_DIRECT writes, but expecting them to understand * that file extension is also an implicit buffered * write is too much. By getting the PR we force * writeback of the buffered zeroing before * proceeding. */ ret = ocfs2_data_lock(inode, 0); if (ret < 0) { mlog_errno(ret); goto out; } ocfs2_data_unlock(inode, 0); } ret = blockdev_direct_IO_no_locking(rw, iocb, inode, inode->i_sb->s_bdev, iov, offset, nr_segs, ocfs2_direct_IO_get_blocks, ocfs2_dio_end_io); out: mlog_exit(ret); return ret; } static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb, u32 cpos, unsigned int *start, unsigned int *end) { unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE; if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) { unsigned int cpp; cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits); cluster_start = cpos % cpp; cluster_start = cluster_start << osb->s_clustersize_bits; cluster_end = cluster_start + osb->s_clustersize; } BUG_ON(cluster_start > PAGE_SIZE); BUG_ON(cluster_end > PAGE_SIZE); if (start) *start = cluster_start; if (end) *end = cluster_end; } /* * 'from' and 'to' are the region in the page to avoid zeroing. * * If pagesize > clustersize, this function will avoid zeroing outside * of the cluster boundary. * * from == to == 0 is code for "zero the entire cluster region" */ static void ocfs2_clear_page_regions(struct page *page, struct ocfs2_super *osb, u32 cpos, unsigned from, unsigned to) { void *kaddr; unsigned int cluster_start, cluster_end; ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end); kaddr = kmap_atomic(page, KM_USER0); if (from || to) { if (from > cluster_start) memset(kaddr + cluster_start, 0, from - cluster_start); if (to < cluster_end) memset(kaddr + to, 0, cluster_end - to); } else { memset(kaddr + cluster_start, 0, cluster_end - cluster_start); } kunmap_atomic(kaddr, KM_USER0); } /* * Some of this taken from block_prepare_write(). We already have our * mapping by now though, and the entire write will be allocating or * it won't, so not much need to use BH_New. * * This will also skip zeroing, which is handled externally. */ int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno, struct inode *inode, unsigned int from, unsigned int to, int new) { int ret = 0; struct buffer_head *head, *bh, *wait[2], **wait_bh = wait; unsigned int block_end, block_start; unsigned int bsize = 1 << inode->i_blkbits; if (!page_has_buffers(page)) create_empty_buffers(page, bsize, 0); head = page_buffers(page); for (bh = head, block_start = 0; bh != head || !block_start; bh = bh->b_this_page, block_start += bsize) { block_end = block_start + bsize; /* * Ignore blocks outside of our i/o range - * they may belong to unallocated clusters. */ if (block_start >= to || block_end <= from) { if (PageUptodate(page)) set_buffer_uptodate(bh); continue; } /* * For an allocating write with cluster size >= page * size, we always write the entire page. */ if (buffer_new(bh)) clear_buffer_new(bh); if (!buffer_mapped(bh)) { map_bh(bh, inode->i_sb, *p_blkno); unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); } if (PageUptodate(page)) { if (!buffer_uptodate(bh)) set_buffer_uptodate(bh); } else if (!buffer_uptodate(bh) && !buffer_delay(bh) && (block_start < from || block_end > to)) { ll_rw_block(READ, 1, &bh); *wait_bh++=bh; } *p_blkno = *p_blkno + 1; } /* * If we issued read requests - let them complete. */ while(wait_bh > wait) { wait_on_buffer(*--wait_bh); if (!buffer_uptodate(*wait_bh)) ret = -EIO; } if (ret == 0 || !new) return ret; /* * If we get -EIO above, zero out any newly allocated blocks * to avoid exposing stale data. */ bh = head; block_start = 0; do { void *kaddr; block_end = block_start + bsize; if (block_end <= from) goto next_bh; if (block_start >= to) break; kaddr = kmap_atomic(page, KM_USER0); memset(kaddr+block_start, 0, bh->b_size); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); set_buffer_uptodate(bh); mark_buffer_dirty(bh); next_bh: block_start = block_end; bh = bh->b_this_page; } while (bh != head); return ret; } /* * This will copy user data from the buffer page in the splice * context. * * For now, we ignore SPLICE_F_MOVE as that would require some extra * communication out all the way to ocfs2_write(). */ int ocfs2_map_and_write_splice_data(struct inode *inode, struct ocfs2_write_ctxt *wc, u64 *p_blkno, unsigned int *ret_from, unsigned int *ret_to) { int ret; unsigned int to, from, cluster_start, cluster_end; char *src, *dst; struct ocfs2_splice_write_priv *sp = wc->w_private; struct pipe_buffer *buf = sp->s_buf; unsigned long bytes, src_from; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start, &cluster_end); from = sp->s_offset; src_from = sp->s_buf_offset; bytes = wc->w_count; if (wc->w_large_pages) { /* * For cluster size < page size, we have to * calculate pos within the cluster and obey * the rightmost boundary. */ bytes = min(bytes, (unsigned long)(osb->s_clustersize - (wc->w_pos & (osb->s_clustersize - 1)))); } to = from + bytes; if (wc->w_this_page_new) ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode, cluster_start, cluster_end, 1); else ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode, from, to, 0); if (ret) { mlog_errno(ret); goto out; } BUG_ON(from > PAGE_CACHE_SIZE); BUG_ON(to > PAGE_CACHE_SIZE); BUG_ON(from > osb->s_clustersize); BUG_ON(to > osb->s_clustersize); src = buf->ops->map(sp->s_pipe, buf, 1); dst = kmap_atomic(wc->w_this_page, KM_USER1); memcpy(dst + from, src + src_from, bytes); kunmap_atomic(wc->w_this_page, KM_USER1); buf->ops->unmap(sp->s_pipe, buf, src); wc->w_finished_copy = 1; *ret_from = from; *ret_to = to; out: return bytes ? (unsigned int)bytes : ret; } /* * This will copy user data from the iovec in the buffered write * context. */ int ocfs2_map_and_write_user_data(struct inode *inode, struct ocfs2_write_ctxt *wc, u64 *p_blkno, unsigned int *ret_from, unsigned int *ret_to) { int ret; unsigned int to, from, cluster_start, cluster_end; unsigned long bytes, src_from; char *dst; struct ocfs2_buffered_write_priv *bp = wc->w_private; const struct iovec *cur_iov = bp->b_cur_iov; char __user *buf; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start, &cluster_end); buf = cur_iov->iov_base + bp->b_cur_off; src_from = (unsigned long)buf & ~PAGE_CACHE_MASK; from = wc->w_pos & (PAGE_CACHE_SIZE - 1); /* * This is a lot of comparisons, but it reads quite * easily, which is important here. */ /* Stay within the src page */ bytes = PAGE_SIZE - src_from; /* Stay within the vector */ bytes = min(bytes, (unsigned long)(cur_iov->iov_len - bp->b_cur_off)); /* Stay within count */ bytes = min(bytes, (unsigned long)wc->w_count); /* * For clustersize > page size, just stay within * target page, otherwise we have to calculate pos * within the cluster and obey the rightmost * boundary. */ if (wc->w_large_pages) { /* * For cluster size < page size, we have to * calculate pos within the cluster and obey * the rightmost boundary. */ bytes = min(bytes, (unsigned long)(osb->s_clustersize - (wc->w_pos & (osb->s_clustersize - 1)))); } else { /* * cluster size > page size is the most common * case - we just stay within the target page * boundary. */ bytes = min(bytes, PAGE_CACHE_SIZE - from); } to = from + bytes; if (wc->w_this_page_new) ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode, cluster_start, cluster_end, 1); else ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode, from, to, 0); if (ret) { mlog_errno(ret); goto out; } BUG_ON(from > PAGE_CACHE_SIZE); BUG_ON(to > PAGE_CACHE_SIZE); BUG_ON(from > osb->s_clustersize); BUG_ON(to > osb->s_clustersize); dst = kmap(wc->w_this_page); memcpy(dst + from, bp->b_src_buf + src_from, bytes); kunmap(wc->w_this_page); /* * XXX: This is slow, but simple. The caller of * ocfs2_buffered_write_cluster() is responsible for * passing through the iovecs, so it's difficult to * predict what our next step is in here after our * initial write. A future version should be pushing * that iovec manipulation further down. * * By setting this, we indicate that a copy from user * data was done, and subsequent calls for this * cluster will skip copying more data. */ wc->w_finished_copy = 1; *ret_from = from; *ret_to = to; out: return bytes ? (unsigned int)bytes : ret; } /* * Map, fill and write a page to disk. * * The work of copying data is done via callback. Newly allocated * pages which don't take user data will be zero'd (set 'new' to * indicate an allocating write) * * Returns a negative error code or the number of bytes copied into * the page. */ int ocfs2_write_data_page(struct inode *inode, handle_t *handle, u64 *p_blkno, struct page *page, struct ocfs2_write_ctxt *wc, int new) { int ret, copied = 0; unsigned int from = 0, to = 0; unsigned int cluster_start, cluster_end; unsigned int zero_from = 0, zero_to = 0; ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), wc->w_cpos, &cluster_start, &cluster_end); if ((wc->w_pos >> PAGE_CACHE_SHIFT) == page->index && !wc->w_finished_copy) { wc->w_this_page = page; wc->w_this_page_new = new; ret = wc->w_write_data_page(inode, wc, p_blkno, &from, &to); if (ret < 0) { mlog_errno(ret); goto out; } copied = ret; zero_from = from; zero_to = to; if (new) { from = cluster_start; to = cluster_end; } } else { /* * If we haven't allocated the new page yet, we * shouldn't be writing it out without copying user * data. This is likely a math error from the caller. */ BUG_ON(!new); from = cluster_start; to = cluster_end; ret = ocfs2_map_page_blocks(page, p_blkno, inode, cluster_start, cluster_end, 1); if (ret) { mlog_errno(ret); goto out; } } /* * Parts of newly allocated pages need to be zero'd. * * Above, we have also rewritten 'to' and 'from' - as far as * the rest of the function is concerned, the entire cluster * range inside of a page needs to be written. * * We can skip this if the page is up to date - it's already * been zero'd from being read in as a hole. */ if (new && !PageUptodate(page)) ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb), wc->w_cpos, zero_from, zero_to); flush_dcache_page(page); if (ocfs2_should_order_data(inode)) { ret = walk_page_buffers(handle, page_buffers(page), from, to, NULL, ocfs2_journal_dirty_data); if (ret < 0) mlog_errno(ret); } /* * We don't use generic_commit_write() because we need to * handle our own i_size update. */ ret = block_commit_write(page, from, to); if (ret) mlog_errno(ret); out: return copied ? copied : ret; } /* * Do the actual write of some data into an inode. Optionally allocate * in order to fulfill the write. * * cpos is the logical cluster offset within the file to write at * * 'phys' is the physical mapping of that offset. a 'phys' value of * zero indicates that allocation is required. In this case, data_ac * and meta_ac should be valid (meta_ac can be null if metadata * allocation isn't required). */ static ssize_t ocfs2_write(struct file *file, u32 phys, handle_t *handle, struct buffer_head *di_bh, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, struct ocfs2_write_ctxt *wc) { int ret, i, numpages = 1, new; unsigned int copied = 0; u32 tmp_pos; u64 v_blkno, p_blkno; struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; unsigned long index, start; struct page **cpages; new = phys == 0 ? 1 : 0; /* * Figure out how many pages we'll be manipulating here. For * non allocating write, we just change the one * page. Otherwise, we'll need a whole clusters worth. */ if (new) numpages = ocfs2_pages_per_cluster(inode->i_sb); cpages = kzalloc(sizeof(*cpages) * numpages, GFP_NOFS); if (!cpages) { ret = -ENOMEM; mlog_errno(ret); return ret; } /* * Fill our page array first. That way we've grabbed enough so * that we can zero and flush if we error after adding the * extent. */ if (new) { start = ocfs2_align_clusters_to_page_index(inode->i_sb, wc->w_cpos); v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, wc->w_cpos); } else { start = wc->w_pos >> PAGE_CACHE_SHIFT; v_blkno = wc->w_pos >> inode->i_sb->s_blocksize_bits; } for(i = 0; i < numpages; i++) { index = start + i; cpages[i] = grab_cache_page(mapping, index); if (!cpages[i]) { ret = -ENOMEM; mlog_errno(ret); goto out; } } if (new) { /* * This is safe to call with the page locks - it won't take * any additional semaphores or cluster locks. */ tmp_pos = wc->w_cpos; ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode, &tmp_pos, 1, di_bh, handle, data_ac, meta_ac, NULL); /* * This shouldn't happen because we must have already * calculated the correct meta data allocation required. The * internal tree allocation code should know how to increase * transaction credits itself. * * If need be, we could handle -EAGAIN for a * RESTART_TRANS here. */ mlog_bug_on_msg(ret == -EAGAIN, "Inode %llu: EAGAIN return during allocation.\n", (unsigned long long)OCFS2_I(inode)->ip_blkno); if (ret < 0) { mlog_errno(ret); goto out; } } ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL, NULL); if (ret < 0) { /* * XXX: Should we go readonly here? */ mlog_errno(ret); goto out; } BUG_ON(p_blkno == 0); for(i = 0; i < numpages; i++) { ret = ocfs2_write_data_page(inode, handle, &p_blkno, cpages[i], wc, new); if (ret < 0) { mlog_errno(ret); goto out; } copied += ret; } out: for(i = 0; i < numpages; i++) { unlock_page(cpages[i]); mark_page_accessed(cpages[i]); page_cache_release(cpages[i]); } kfree(cpages); return copied ? copied : ret; } static void ocfs2_write_ctxt_init(struct ocfs2_write_ctxt *wc, struct ocfs2_super *osb, loff_t pos, size_t count, ocfs2_page_writer *cb, void *cb_priv) { wc->w_count = count; wc->w_pos = pos; wc->w_cpos = wc->w_pos >> osb->s_clustersize_bits; wc->w_finished_copy = 0; if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) wc->w_large_pages = 1; else wc->w_large_pages = 0; wc->w_write_data_page = cb; wc->w_private = cb_priv; } /* * Write a cluster to an inode. The cluster may not be allocated yet, * in which case it will be. This only exists for buffered writes - * O_DIRECT takes a more "traditional" path through the kernel. * * The caller is responsible for incrementing pos, written counts, etc * * For file systems that don't support sparse files, pre-allocation * and page zeroing up until cpos should be done prior to this * function call. * * Callers should be holding i_sem, and the rw cluster lock. * * Returns the number of user bytes written, or less than zero for * error. */ ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos, size_t count, ocfs2_page_writer *actor, void *priv) { int ret, credits = OCFS2_INODE_UPDATE_CREDITS; ssize_t written = 0; u32 phys; struct inode *inode = file->f_mapping->host; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); struct buffer_head *di_bh = NULL; struct ocfs2_dinode *di; struct ocfs2_alloc_context *data_ac = NULL; struct ocfs2_alloc_context *meta_ac = NULL; handle_t *handle; struct ocfs2_write_ctxt wc; ocfs2_write_ctxt_init(&wc, osb, pos, count, actor, priv); ret = ocfs2_meta_lock(inode, &di_bh, 1); if (ret) { mlog_errno(ret); goto out; } di = (struct ocfs2_dinode *)di_bh->b_data; /* * Take alloc sem here to prevent concurrent lookups. That way * the mapping, zeroing and tree manipulation within * ocfs2_write() will be safe against ->readpage(). This * should also serve to lock out allocation from a shared * writeable region. */ down_write(&OCFS2_I(inode)->ip_alloc_sem); ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL, NULL); if (ret) { mlog_errno(ret); goto out_meta; } /* phys == 0 means that allocation is required. */ if (phys == 0) { ret = ocfs2_lock_allocators(inode, di, 1, &data_ac, &meta_ac); if (ret) { mlog_errno(ret); goto out_meta; } credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1); } ret = ocfs2_data_lock(inode, 1); if (ret) { mlog_errno(ret); goto out_meta; } handle = ocfs2_start_trans(osb, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); mlog_errno(ret); goto out_data; } written = ocfs2_write(file, phys, handle, di_bh, data_ac, meta_ac, &wc); if (written < 0) { ret = written; mlog_errno(ret); goto out_commit; } ret = ocfs2_journal_access(handle, inode, di_bh, OCFS2_JOURNAL_ACCESS_WRITE); if (ret) { mlog_errno(ret); goto out_commit; } pos += written; if (pos > inode->i_size) { i_size_write(inode, pos); mark_inode_dirty(inode); } inode->i_blocks = ocfs2_align_bytes_to_sectors((u64)(i_size_read(inode))); di->i_size = cpu_to_le64((u64)i_size_read(inode)); inode->i_mtime = inode->i_ctime = CURRENT_TIME; di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec); di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec); ret = ocfs2_journal_dirty(handle, di_bh); if (ret) mlog_errno(ret); out_commit: ocfs2_commit_trans(osb, handle); out_data: ocfs2_data_unlock(inode, 1); out_meta: up_write(&OCFS2_I(inode)->ip_alloc_sem); ocfs2_meta_unlock(inode, 1); out: brelse(di_bh); if (data_ac) ocfs2_free_alloc_context(data_ac); if (meta_ac) ocfs2_free_alloc_context(meta_ac); return written ? written : ret; } const struct address_space_operations ocfs2_aops = { .readpage = ocfs2_readpage, .writepage = ocfs2_writepage, .bmap = ocfs2_bmap, .sync_page = block_sync_page, .direct_IO = ocfs2_direct_IO, .invalidatepage = ocfs2_invalidatepage, .releasepage = ocfs2_releasepage, .migratepage = buffer_migrate_page, };