/* -*- 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 <linux/fs.h> #include <linux/slab.h> #include <linux/highmem.h> #include <linux/pagemap.h> #include <asm/byteorder.h> #include <linux/swap.h> #include <linux/pipe_fs_i.h> #include <linux/mpage.h> #include <linux/quotaops.h> #define MLOG_MASK_PREFIX ML_FILE_IO #include <cluster/masklog.h> #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 "refcounttree.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_inode_block(inode, &bh); if (status < 0) { mlog_errno(status); goto bail; } fe = (struct ocfs2_dinode *) bh->b_data; 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: brelse(bh); mlog_exit(err); return err; } 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 max_blocks = bh_result->b_size >> inode->i_blkbits; u64 p_blkno, count, 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, &count, &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; } if (max_blocks < count) count = max_blocks; /* * 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. * * If we see this on a sparse file system, then a truncate has * raced us and removed the cluster. In this case, we clear * the buffers dirty and uptodate bits and let the buffer code * ignore it as a hole. */ if (create && p_blkno == 0 && ocfs2_sparse_alloc(osb)) { clear_buffer_dirty(bh_result); clear_buffer_uptodate(bh_result); goto bail; } /* 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); bh_result->b_size = count << inode->i_blkbits; 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(); goto bail; } 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; } int ocfs2_read_inline_data(struct inode *inode, struct page *page, struct buffer_head *di_bh) { void *kaddr; loff_t size; struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; if (!(le16_to_cpu(di->i_dyn_features) & OCFS2_INLINE_DATA_FL)) { ocfs2_error(inode->i_sb, "Inode %llu lost inline data flag", (unsigned long long)OCFS2_I(inode)->ip_blkno); return -EROFS; } size = i_size_read(inode); if (size > PAGE_CACHE_SIZE || size > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) { ocfs2_error(inode->i_sb, "Inode %llu has with inline data has bad size: %Lu", (unsigned long long)OCFS2_I(inode)->ip_blkno, (unsigned long long)size); return -EROFS; } kaddr = kmap_atomic(page, KM_USER0); if (size) memcpy(kaddr, di->id2.i_data.id_data, size); /* Clear the remaining part of the page */ memset(kaddr + size, 0, PAGE_CACHE_SIZE - size); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); SetPageUptodate(page); return 0; } static int ocfs2_readpage_inline(struct inode *inode, struct page *page) { int ret; struct buffer_head *di_bh = NULL; BUG_ON(!PageLocked(page)); BUG_ON(!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)); ret = ocfs2_read_inode_block(inode, &di_bh); if (ret) { mlog_errno(ret); goto out; } ret = ocfs2_read_inline_data(inode, page, di_bh); out: unlock_page(page); brelse(di_bh); return ret; } static int ocfs2_readpage(struct file *file, struct page *page) { struct inode *inode = page->mapping->host; struct ocfs2_inode_info *oi = OCFS2_I(inode); 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_inode_lock_with_page(inode, NULL, 0, page); if (ret != 0) { if (ret == AOP_TRUNCATED_PAGE) unlock = 0; mlog_errno(ret); goto out; } if (down_read_trylock(&oi->ip_alloc_sem) == 0) { ret = AOP_TRUNCATED_PAGE; goto out_inode_unlock; } /* * 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, vm_ops->fault) 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)) { zero_user(page, 0, PAGE_SIZE); SetPageUptodate(page); ret = 0; goto out_alloc; } if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) ret = ocfs2_readpage_inline(inode, page); else ret = block_read_full_page(page, ocfs2_get_block); unlock = 0; out_alloc: up_read(&OCFS2_I(inode)->ip_alloc_sem); out_inode_unlock: ocfs2_inode_unlock(inode, 0); out: if (unlock) unlock_page(page); mlog_exit(ret); return ret; } /* * This is used only for read-ahead. Failures or difficult to handle * situations are safe to ignore. * * Right now, we don't bother with BH_Boundary - in-inode extent lists * are quite large (243 extents on 4k blocks), so most inodes don't * grow out to a tree. If need be, detecting boundary extents could * trivially be added in a future version of ocfs2_get_block(). */ static int ocfs2_readpages(struct file *filp, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { int ret, err = -EIO; struct inode *inode = mapping->host; struct ocfs2_inode_info *oi = OCFS2_I(inode); loff_t start; struct page *last; /* * Use the nonblocking flag for the dlm code to avoid page * lock inversion, but don't bother with retrying. */ ret = ocfs2_inode_lock_full(inode, NULL, 0, OCFS2_LOCK_NONBLOCK); if (ret) return err; if (down_read_trylock(&oi->ip_alloc_sem) == 0) { ocfs2_inode_unlock(inode, 0); return err; } /* * Don't bother with inline-data. There isn't anything * to read-ahead in that case anyway... */ if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) goto out_unlock; /* * Check whether a remote node truncated this file - we just * drop out in that case as it's not worth handling here. */ last = list_entry(pages->prev, struct page, lru); start = (loff_t)last->index << PAGE_CACHE_SHIFT; if (start >= i_size_read(inode)) goto out_unlock; err = mpage_readpages(mapping, pages, nr_pages, ocfs2_get_block); out_unlock: up_read(&oi->ip_alloc_sem); ocfs2_inode_unlock(inode, 0); return err; } /* 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; ret = block_prepare_write(page, from, to, ocfs2_get_block); 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; int ret = 0; handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); if (IS_ERR(handle)) { ret = -ENOMEM; mlog_errno(ret); goto out; } if (ocfs2_should_order_data(inode)) { ret = ocfs2_jbd2_file_inode(handle, inode); if (ret < 0) mlog_errno(ret); } out: if (ret) { if (!IS_ERR(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_inode_lock(inode, NULL, 0); if (err) { if (err != -ENOENT) mlog_errno(err); goto bail; } down_read(&OCFS2_I(inode)->ip_alloc_sem); } if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) 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_inode_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); * * Note that we never bother to allocate blocks here, and thus ignore the * create argument. */ 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)); /* 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; } /* We should already CoW the refcounted extent. */ BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED); /* * 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 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; int level; /* 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); level = ocfs2_iocb_rw_locked_level(iocb); if (!level) up_read(&inode->i_alloc_sem); ocfs2_rw_unlock(inode, level); } /* * 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; jbd2_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 jbd2_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(); /* * Fallback to buffered I/O if we see an inode without * extents. */ if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) return 0; /* Fallback to buffered I/O if we are appending. */ if (i_size_read(inode) <= offset) return 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); 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); } /* * Nonsparse file systems fully allocate before we get to the write * code. This prevents ocfs2_write() from tagging the write as an * allocating one, which means ocfs2_map_page_blocks() might try to * read-in the blocks at the tail of our file. Avoid reading them by * testing i_size against each block offset. */ static int ocfs2_should_read_blk(struct inode *inode, struct page *page, unsigned int block_start) { u64 offset = page_offset(page) + block_start; if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) return 1; if (i_size_read(inode) > offset) return 1; return 0; } /* * 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; clear_buffer_new(bh); /* * 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 (new) set_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) && !buffer_new(bh) && ocfs2_should_read_blk(inode, page, block_start) && (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 { block_end = block_start + bsize; if (block_end <= from) goto next_bh; if (block_start >= to) break; zero_user(page, block_start, bh->b_size); set_buffer_uptodate(bh); mark_buffer_dirty(bh); next_bh: block_start = block_end; bh = bh->b_this_page; } while (bh != head); return ret; } #if (PAGE_CACHE_SIZE >= OCFS2_MAX_CLUSTERSIZE) #define OCFS2_MAX_CTXT_PAGES 1 #else #define OCFS2_MAX_CTXT_PAGES (OCFS2_MAX_CLUSTERSIZE / PAGE_CACHE_SIZE) #endif #define OCFS2_MAX_CLUSTERS_PER_PAGE (PAGE_CACHE_SIZE / OCFS2_MIN_CLUSTERSIZE) /* * Describe the state of a single cluster to be written to. */ struct ocfs2_write_cluster_desc { u32 c_cpos; u32 c_phys; /* * Give this a unique field because c_phys eventually gets * filled. */ unsigned c_new; unsigned c_unwritten; unsigned c_needs_zero; }; struct ocfs2_write_ctxt { /* Logical cluster position / len of write */ u32 w_cpos; u32 w_clen; /* First cluster allocated in a nonsparse extend */ u32 w_first_new_cpos; struct ocfs2_write_cluster_desc w_desc[OCFS2_MAX_CLUSTERS_PER_PAGE]; /* * This is true if page_size > cluster_size. * * It triggers a set of special cases during write which might * have to deal with allocating writes to partial pages. */ unsigned int w_large_pages; /* * Pages involved in this write. * * w_target_page is the page being written to by the user. * * w_pages is an array of pages which always contains * w_target_page, and in the case of an allocating write with * page_size < cluster size, it will contain zero'd and mapped * pages adjacent to w_target_page which need to be written * out in so that future reads from that region will get * zero's. */ struct page *w_pages[OCFS2_MAX_CTXT_PAGES]; unsigned int w_num_pages; struct page *w_target_page; /* * ocfs2_write_end() uses this to know what the real range to * write in the target should be. */ unsigned int w_target_from; unsigned int w_target_to; /* * We could use journal_current_handle() but this is cleaner, * IMHO -Mark */ handle_t *w_handle; struct buffer_head *w_di_bh; struct ocfs2_cached_dealloc_ctxt w_dealloc; }; void ocfs2_unlock_and_free_pages(struct page **pages, int num_pages) { int i; for(i = 0; i < num_pages; i++) { if (pages[i]) { unlock_page(pages[i]); mark_page_accessed(pages[i]); page_cache_release(pages[i]); } } } static void ocfs2_free_write_ctxt(struct ocfs2_write_ctxt *wc) { ocfs2_unlock_and_free_pages(wc->w_pages, wc->w_num_pages); brelse(wc->w_di_bh); kfree(wc); } static int ocfs2_alloc_write_ctxt(struct ocfs2_write_ctxt **wcp, struct ocfs2_super *osb, loff_t pos, unsigned len, struct buffer_head *di_bh) { u32 cend; struct ocfs2_write_ctxt *wc; wc = kzalloc(sizeof(struct ocfs2_write_ctxt), GFP_NOFS); if (!wc) return -ENOMEM; wc->w_cpos = pos >> osb->s_clustersize_bits; wc->w_first_new_cpos = UINT_MAX; cend = (pos + len - 1) >> osb->s_clustersize_bits; wc->w_clen = cend - wc->w_cpos + 1; get_bh(di_bh); wc->w_di_bh = di_bh; if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) wc->w_large_pages = 1; else wc->w_large_pages = 0; ocfs2_init_dealloc_ctxt(&wc->w_dealloc); *wcp = wc; return 0; } /* * If a page has any new buffers, zero them out here, and mark them uptodate * and dirty so they'll be written out (in order to prevent uninitialised * block data from leaking). And clear the new bit. */ static void ocfs2_zero_new_buffers(struct page *page, unsigned from, unsigned to) { unsigned int block_start, block_end; struct buffer_head *head, *bh; BUG_ON(!PageLocked(page)); if (!page_has_buffers(page)) return; bh = head = page_buffers(page); block_start = 0; do { block_end = block_start + bh->b_size; if (buffer_new(bh)) { if (block_end > from && block_start < to) { if (!PageUptodate(page)) { unsigned start, end; start = max(from, block_start); end = min(to, block_end); zero_user_segment(page, start, end); set_buffer_uptodate(bh); } clear_buffer_new(bh); mark_buffer_dirty(bh); } } block_start = block_end; bh = bh->b_this_page; } while (bh != head); } /* * Only called when we have a failure during allocating write to write * zero's to the newly allocated region. */ static void ocfs2_write_failure(struct inode *inode, struct ocfs2_write_ctxt *wc, loff_t user_pos, unsigned user_len) { int i; unsigned from = user_pos & (PAGE_CACHE_SIZE - 1), to = user_pos + user_len; struct page *tmppage; ocfs2_zero_new_buffers(wc->w_target_page, from, to); for(i = 0; i < wc->w_num_pages; i++) { tmppage = wc->w_pages[i]; if (page_has_buffers(tmppage)) { if (ocfs2_should_order_data(inode)) ocfs2_jbd2_file_inode(wc->w_handle, inode); block_commit_write(tmppage, from, to); } } } static int ocfs2_prepare_page_for_write(struct inode *inode, u64 *p_blkno, struct ocfs2_write_ctxt *wc, struct page *page, u32 cpos, loff_t user_pos, unsigned user_len, int new) { int ret; unsigned int map_from = 0, map_to = 0; unsigned int cluster_start, cluster_end; unsigned int user_data_from = 0, user_data_to = 0; ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), cpos, &cluster_start, &cluster_end); if (page == wc->w_target_page) { map_from = user_pos & (PAGE_CACHE_SIZE - 1); map_to = map_from + user_len; if (new) ret = ocfs2_map_page_blocks(page, p_blkno, inode, cluster_start, cluster_end, new); else ret = ocfs2_map_page_blocks(page, p_blkno, inode, map_from, map_to, new); if (ret) { mlog_errno(ret); goto out; } user_data_from = map_from; user_data_to = map_to; if (new) { map_from = cluster_start; map_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); map_from = cluster_start; map_to = cluster_end; ret = ocfs2_map_page_blocks(page, p_blkno, inode, cluster_start, cluster_end, new); 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), cpos, user_data_from, user_data_to); flush_dcache_page(page); out: return ret; } /* * This function will only grab one clusters worth of pages. */ static int ocfs2_grab_pages_for_write(struct address_space *mapping, struct ocfs2_write_ctxt *wc, u32 cpos, loff_t user_pos, int new, struct page *mmap_page) { int ret = 0, i; unsigned long start, target_index, index; struct inode *inode = mapping->host; target_index = user_pos >> PAGE_CACHE_SHIFT; /* * 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) { wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); } else { wc->w_num_pages = 1; start = target_index; } for(i = 0; i < wc->w_num_pages; i++) { index = start + i; if (index == target_index && mmap_page) { /* * ocfs2_pagemkwrite() is a little different * and wants us to directly use the page * passed in. */ lock_page(mmap_page); if (mmap_page->mapping != mapping) { unlock_page(mmap_page); /* * Sanity check - the locking in * ocfs2_pagemkwrite() should ensure * that this code doesn't trigger. */ ret = -EINVAL; mlog_errno(ret); goto out; } page_cache_get(mmap_page); wc->w_pages[i] = mmap_page; } else { wc->w_pages[i] = find_or_create_page(mapping, index, GFP_NOFS); if (!wc->w_pages[i]) { ret = -ENOMEM; mlog_errno(ret); goto out; } } if (index == target_index) wc->w_target_page = wc->w_pages[i]; } out: return ret; } /* * Prepare a single cluster for write one cluster into the file. */ static int ocfs2_write_cluster(struct address_space *mapping, u32 phys, unsigned int unwritten, unsigned int should_zero, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, struct ocfs2_write_ctxt *wc, u32 cpos, loff_t user_pos, unsigned user_len) { int ret, i, new; u64 v_blkno, p_blkno; struct inode *inode = mapping->host; struct ocfs2_extent_tree et; new = phys == 0 ? 1 : 0; if (new) { u32 tmp_pos; /* * This is safe to call with the page locks - it won't take * any additional semaphores or cluster locks. */ tmp_pos = cpos; ret = ocfs2_add_inode_data(OCFS2_SB(inode->i_sb), inode, &tmp_pos, 1, 0, wc->w_di_bh, wc->w_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; } } else if (unwritten) { ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), wc->w_di_bh); ret = ocfs2_mark_extent_written(inode, &et, wc->w_handle, cpos, 1, phys, meta_ac, &wc->w_dealloc); if (ret < 0) { mlog_errno(ret); goto out; } } if (should_zero) v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, cpos); else v_blkno = user_pos >> inode->i_sb->s_blocksize_bits; /* * The only reason this should fail is due to an inability to * find the extent added. */ ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL, NULL); if (ret < 0) { ocfs2_error(inode->i_sb, "Corrupting extend for inode %llu, " "at logical block %llu", (unsigned long long)OCFS2_I(inode)->ip_blkno, (unsigned long long)v_blkno); goto out; } BUG_ON(p_blkno == 0); for(i = 0; i < wc->w_num_pages; i++) { int tmpret; tmpret = ocfs2_prepare_page_for_write(inode, &p_blkno, wc, wc->w_pages[i], cpos, user_pos, user_len, should_zero); if (tmpret) { mlog_errno(tmpret); if (ret == 0) ret = tmpret; } } /* * We only have cleanup to do in case of allocating write. */ if (ret && new) ocfs2_write_failure(inode, wc, user_pos, user_len); out: return ret; } static int ocfs2_write_cluster_by_desc(struct address_space *mapping, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, struct ocfs2_write_ctxt *wc, loff_t pos, unsigned len) { int ret, i; loff_t cluster_off; unsigned int local_len = len; struct ocfs2_write_cluster_desc *desc; struct ocfs2_super *osb = OCFS2_SB(mapping->host->i_sb); for (i = 0; i < wc->w_clen; i++) { desc = &wc->w_desc[i]; /* * We have to make sure that the total write passed in * doesn't extend past a single cluster. */ local_len = len; cluster_off = pos & (osb->s_clustersize - 1); if ((cluster_off + local_len) > osb->s_clustersize) local_len = osb->s_clustersize - cluster_off; ret = ocfs2_write_cluster(mapping, desc->c_phys, desc->c_unwritten, desc->c_needs_zero, data_ac, meta_ac, wc, desc->c_cpos, pos, local_len); if (ret) { mlog_errno(ret); goto out; } len -= local_len; pos += local_len; } ret = 0; out: return ret; } /* * ocfs2_write_end() wants to know which parts of the target page it * should complete the write on. It's easiest to compute them ahead of * time when a more complete view of the write is available. */ static void ocfs2_set_target_boundaries(struct ocfs2_super *osb, struct ocfs2_write_ctxt *wc, loff_t pos, unsigned len, int alloc) { struct ocfs2_write_cluster_desc *desc; wc->w_target_from = pos & (PAGE_CACHE_SIZE - 1); wc->w_target_to = wc->w_target_from + len; if (alloc == 0) return; /* * Allocating write - we may have different boundaries based * on page size and cluster size. * * NOTE: We can no longer compute one value from the other as * the actual write length and user provided length may be * different. */ if (wc->w_large_pages) { /* * We only care about the 1st and last cluster within * our range and whether they should be zero'd or not. Either * value may be extended out to the start/end of a * newly allocated cluster. */ desc = &wc->w_desc[0]; if (desc->c_needs_zero) ocfs2_figure_cluster_boundaries(osb, desc->c_cpos, &wc->w_target_from, NULL); desc = &wc->w_desc[wc->w_clen - 1]; if (desc->c_needs_zero) ocfs2_figure_cluster_boundaries(osb, desc->c_cpos, NULL, &wc->w_target_to); } else { wc->w_target_from = 0; wc->w_target_to = PAGE_CACHE_SIZE; } } /* * Populate each single-cluster write descriptor in the write context * with information about the i/o to be done. * * Returns the number of clusters that will have to be allocated, as * well as a worst case estimate of the number of extent records that * would have to be created during a write to an unwritten region. */ static int ocfs2_populate_write_desc(struct inode *inode, struct ocfs2_write_ctxt *wc, unsigned int *clusters_to_alloc, unsigned int *extents_to_split) { int ret; struct ocfs2_write_cluster_desc *desc; unsigned int num_clusters = 0; unsigned int ext_flags = 0; u32 phys = 0; int i; *clusters_to_alloc = 0; *extents_to_split = 0; for (i = 0; i < wc->w_clen; i++) { desc = &wc->w_desc[i]; desc->c_cpos = wc->w_cpos + i; if (num_clusters == 0) { /* * Need to look up the next extent record. */ ret = ocfs2_get_clusters(inode, desc->c_cpos, &phys, &num_clusters, &ext_flags); if (ret) { mlog_errno(ret); goto out; } /* We should already CoW the refcountd extent. */ BUG_ON(ext_flags & OCFS2_EXT_REFCOUNTED); /* * Assume worst case - that we're writing in * the middle of the extent. * * We can assume that the write proceeds from * left to right, in which case the extent * insert code is smart enough to coalesce the * next splits into the previous records created. */ if (ext_flags & OCFS2_EXT_UNWRITTEN) *extents_to_split = *extents_to_split + 2; } else if (phys) { /* * Only increment phys if it doesn't describe * a hole. */ phys++; } /* * If w_first_new_cpos is < UINT_MAX, we have a non-sparse * file that got extended. w_first_new_cpos tells us * where the newly allocated clusters are so we can * zero them. */ if (desc->c_cpos >= wc->w_first_new_cpos) { BUG_ON(phys == 0); desc->c_needs_zero = 1; } desc->c_phys = phys; if (phys == 0) { desc->c_new = 1; desc->c_needs_zero = 1; *clusters_to_alloc = *clusters_to_alloc + 1; } if (ext_flags & OCFS2_EXT_UNWRITTEN) { desc->c_unwritten = 1; desc->c_needs_zero = 1; } num_clusters--; } ret = 0; out: return ret; } static int ocfs2_write_begin_inline(struct address_space *mapping, struct inode *inode, struct ocfs2_write_ctxt *wc) { int ret; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); struct page *page; handle_t *handle; struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; page = find_or_create_page(mapping, 0, GFP_NOFS); if (!page) { ret = -ENOMEM; mlog_errno(ret); goto out; } /* * If we don't set w_num_pages then this page won't get unlocked * and freed on cleanup of the write context. */ wc->w_pages[0] = wc->w_target_page = page; wc->w_num_pages = 1; handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS); if (IS_ERR(handle)) { ret = PTR_ERR(handle); mlog_errno(ret); goto out; } ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE); if (ret) { ocfs2_commit_trans(osb, handle); mlog_errno(ret); goto out; } if (!(OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)) ocfs2_set_inode_data_inline(inode, di); if (!PageUptodate(page)) { ret = ocfs2_read_inline_data(inode, page, wc->w_di_bh); if (ret) { ocfs2_commit_trans(osb, handle); goto out; } } wc->w_handle = handle; out: return ret; } int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size) { struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; if (new_size <= le16_to_cpu(di->id2.i_data.id_count)) return 1; return 0; } static int ocfs2_try_to_write_inline_data(struct address_space *mapping, struct inode *inode, loff_t pos, unsigned len, struct page *mmap_page, struct ocfs2_write_ctxt *wc) { int ret, written = 0; loff_t end = pos + len; struct ocfs2_inode_info *oi = OCFS2_I(inode); struct ocfs2_dinode *di = NULL; mlog(0, "Inode %llu, write of %u bytes at off %llu. features: 0x%x\n", (unsigned long long)oi->ip_blkno, len, (unsigned long long)pos, oi->ip_dyn_features); /* * Handle inodes which already have inline data 1st. */ if (oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) { if (mmap_page == NULL && ocfs2_size_fits_inline_data(wc->w_di_bh, end)) goto do_inline_write; /* * The write won't fit - we have to give this inode an * inline extent list now. */ ret = ocfs2_convert_inline_data_to_extents(inode, wc->w_di_bh); if (ret) mlog_errno(ret); goto out; } /* * Check whether the inode can accept inline data. */ if (oi->ip_clusters != 0 || i_size_read(inode) != 0) return 0; /* * Check whether the write can fit. */ di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; if (mmap_page || end > ocfs2_max_inline_data_with_xattr(inode->i_sb, di)) return 0; do_inline_write: ret = ocfs2_write_begin_inline(mapping, inode, wc); if (ret) { mlog_errno(ret); goto out; } /* * This signals to the caller that the data can be written * inline. */ written = 1; out: return written ? written : ret; } /* * This function only does anything for file systems which can't * handle sparse files. * * What we want to do here is fill in any hole between the current end * of allocation and the end of our write. That way the rest of the * write path can treat it as an non-allocating write, which has no * special case code for sparse/nonsparse files. */ static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos, unsigned len, struct ocfs2_write_ctxt *wc) { int ret; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); loff_t newsize = pos + len; if (ocfs2_sparse_alloc(osb)) return 0; if (newsize <= i_size_read(inode)) return 0; ret = ocfs2_extend_no_holes(inode, newsize, pos); if (ret) mlog_errno(ret); wc->w_first_new_cpos = ocfs2_clusters_for_bytes(inode->i_sb, i_size_read(inode)); return ret; } int ocfs2_write_begin_nolock(struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata, struct buffer_head *di_bh, struct page *mmap_page) { int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS; unsigned int clusters_to_alloc, extents_to_split; struct ocfs2_write_ctxt *wc; struct inode *inode = mapping->host; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); struct ocfs2_dinode *di; struct ocfs2_alloc_context *data_ac = NULL; struct ocfs2_alloc_context *meta_ac = NULL; handle_t *handle; struct ocfs2_extent_tree et; ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh); if (ret) { mlog_errno(ret); return ret; } if (ocfs2_supports_inline_data(osb)) { ret = ocfs2_try_to_write_inline_data(mapping, inode, pos, len, mmap_page, wc); if (ret == 1) { ret = 0; goto success; } if (ret < 0) { mlog_errno(ret); goto out; } } ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc); if (ret) { mlog_errno(ret); goto out; } ret = ocfs2_check_range_for_refcount(inode, pos, len); if (ret < 0) { mlog_errno(ret); goto out; } else if (ret == 1) { ret = ocfs2_refcount_cow(inode, di_bh, wc->w_cpos, wc->w_clen, UINT_MAX); if (ret) { mlog_errno(ret); goto out; } } ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc, &extents_to_split); if (ret) { mlog_errno(ret); goto out; } di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; /* * We set w_target_from, w_target_to here so that * ocfs2_write_end() knows which range in the target page to * write out. An allocation requires that we write the entire * cluster range. */ if (clusters_to_alloc || extents_to_split) { /* * XXX: We are stretching the limits of * ocfs2_lock_allocators(). It greatly over-estimates * the work to be done. */ mlog(0, "extend inode %llu, i_size = %lld, di->i_clusters = %u," " clusters_to_add = %u, extents_to_split = %u\n", (unsigned long long)OCFS2_I(inode)->ip_blkno, (long long)i_size_read(inode), le32_to_cpu(di->i_clusters), clusters_to_alloc, extents_to_split); ocfs2_init_dinode_extent_tree(&et, INODE_CACHE(inode), wc->w_di_bh); ret = ocfs2_lock_allocators(inode, &et, clusters_to_alloc, extents_to_split, &data_ac, &meta_ac); if (ret) { mlog_errno(ret); goto out; } credits = ocfs2_calc_extend_credits(inode->i_sb, &di->id2.i_list, clusters_to_alloc); } /* * We have to zero sparse allocated clusters, unwritten extent clusters, * and non-sparse clusters we just extended. For non-sparse writes, * we know zeros will only be needed in the first and/or last cluster. */ if (clusters_to_alloc || extents_to_split || (wc->w_clen && (wc->w_desc[0].c_needs_zero || wc->w_desc[wc->w_clen - 1].c_needs_zero))) cluster_of_pages = 1; else cluster_of_pages = 0; ocfs2_set_target_boundaries(osb, wc, pos, len, cluster_of_pages); handle = ocfs2_start_trans(osb, credits); if (IS_ERR(handle)) { ret = PTR_ERR(handle); mlog_errno(ret); goto out; } wc->w_handle = handle; if (clusters_to_alloc && vfs_dq_alloc_space_nodirty(inode, ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc))) { ret = -EDQUOT; goto out_commit; } /* * We don't want this to fail in ocfs2_write_end(), so do it * here. */ ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), wc->w_di_bh, OCFS2_JOURNAL_ACCESS_WRITE); if (ret) { mlog_errno(ret); goto out_quota; } /* * 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. */ ret = ocfs2_grab_pages_for_write(mapping, wc, wc->w_cpos, pos, cluster_of_pages, mmap_page); if (ret) { mlog_errno(ret); goto out_quota; } ret = ocfs2_write_cluster_by_desc(mapping, data_ac, meta_ac, wc, pos, len); if (ret) { mlog_errno(ret); goto out_quota; } if (data_ac) ocfs2_free_alloc_context(data_ac); if (meta_ac) ocfs2_free_alloc_context(meta_ac); success: *pagep = wc->w_target_page; *fsdata = wc; return 0; out_quota: if (clusters_to_alloc) vfs_dq_free_space(inode, ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc)); out_commit: ocfs2_commit_trans(osb, handle); out: ocfs2_free_write_ctxt(wc); if (data_ac) ocfs2_free_alloc_context(data_ac); if (meta_ac) ocfs2_free_alloc_context(meta_ac); return ret; } static int ocfs2_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) { int ret; struct buffer_head *di_bh = NULL; struct inode *inode = mapping->host; ret = ocfs2_inode_lock(inode, &di_bh, 1); if (ret) { mlog_errno(ret); return ret; } /* * 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_write_begin_nolock(mapping, pos, len, flags, pagep, fsdata, di_bh, NULL); if (ret) { mlog_errno(ret); goto out_fail; } brelse(di_bh); return 0; out_fail: up_write(&OCFS2_I(inode)->ip_alloc_sem); brelse(di_bh); ocfs2_inode_unlock(inode, 1); return ret; } static void ocfs2_write_end_inline(struct inode *inode, loff_t pos, unsigned len, unsigned *copied, struct ocfs2_dinode *di, struct ocfs2_write_ctxt *wc) { void *kaddr; if (unlikely(*copied < len)) { if (!PageUptodate(wc->w_target_page)) { *copied = 0; return; } } kaddr = kmap_atomic(wc->w_target_page, KM_USER0); memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied); kunmap_atomic(kaddr, KM_USER0); mlog(0, "Data written to inode at offset %llu. " "id_count = %u, copied = %u, i_dyn_features = 0x%x\n", (unsigned long long)pos, *copied, le16_to_cpu(di->id2.i_data.id_count), le16_to_cpu(di->i_dyn_features)); } int ocfs2_write_end_nolock(struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { int i; unsigned from, to, start = pos & (PAGE_CACHE_SIZE - 1); struct inode *inode = mapping->host; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); struct ocfs2_write_ctxt *wc = fsdata; struct ocfs2_dinode *di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; handle_t *handle = wc->w_handle; struct page *tmppage; if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) { ocfs2_write_end_inline(inode, pos, len, &copied, di, wc); goto out_write_size; } if (unlikely(copied < len)) { if (!PageUptodate(wc->w_target_page)) copied = 0; ocfs2_zero_new_buffers(wc->w_target_page, start+copied, start+len); } flush_dcache_page(wc->w_target_page); for(i = 0; i < wc->w_num_pages; i++) { tmppage = wc->w_pages[i]; if (tmppage == wc->w_target_page) { from = wc->w_target_from; to = wc->w_target_to; BUG_ON(from > PAGE_CACHE_SIZE || to > PAGE_CACHE_SIZE || to < from); } else { /* * Pages adjacent to the target (if any) imply * a hole-filling write in which case we want * to flush their entire range. */ from = 0; to = PAGE_CACHE_SIZE; } if (page_has_buffers(tmppage)) { if (ocfs2_should_order_data(inode)) ocfs2_jbd2_file_inode(wc->w_handle, inode); block_commit_write(tmppage, from, to); } } out_write_size: pos += copied; if (pos > inode->i_size) { i_size_write(inode, pos); mark_inode_dirty(inode); } inode->i_blocks = ocfs2_inode_sector_count(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); ocfs2_journal_dirty(handle, wc->w_di_bh); ocfs2_commit_trans(osb, handle); ocfs2_run_deallocs(osb, &wc->w_dealloc); ocfs2_free_write_ctxt(wc); return copied; } static int ocfs2_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) { int ret; struct inode *inode = mapping->host; ret = ocfs2_write_end_nolock(mapping, pos, len, copied, page, fsdata); up_write(&OCFS2_I(inode)->ip_alloc_sem); ocfs2_inode_unlock(inode, 1); return ret; } const struct address_space_operations ocfs2_aops = { .readpage = ocfs2_readpage, .readpages = ocfs2_readpages, .writepage = ocfs2_writepage, .write_begin = ocfs2_write_begin, .write_end = ocfs2_write_end, .bmap = ocfs2_bmap, .sync_page = block_sync_page, .direct_IO = ocfs2_direct_IO, .invalidatepage = ocfs2_invalidatepage, .releasepage = ocfs2_releasepage, .migratepage = buffer_migrate_page, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, };