diff options
Diffstat (limited to 'fs/ocfs2/aops.c')
| -rw-r--r-- | fs/ocfs2/aops.c | 2099 |
1 files changed, 2099 insertions, 0 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c new file mode 100644 index 00000000..65774325 --- /dev/null +++ b/fs/ocfs2/aops.c @@ -0,0 +1,2099 @@ +/* -*- 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> + +#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 "ocfs2_trace.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; + + trace_ocfs2_symlink_get_block( + (unsigned long long)OCFS2_I(inode)->ip_blkno, + (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); + 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); + 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); + + 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); + + trace_ocfs2_get_block((unsigned long long)OCFS2_I(inode)->ip_blkno, + (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_write_begin() 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)); + + trace_ocfs2_get_block_end((unsigned long long)OCFS2_I(inode)->ip_blkno, + (unsigned long long)past_eof); + if (create && (iblock >= past_eof)) + set_buffer_new(bh_result); + +bail: + if (err < 0) + err = -EIO; + + 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); + 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); + + 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; + + trace_ocfs2_readpage((unsigned long long)oi->ip_blkno, + (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) { + /* + * Unlock the page and cycle ip_alloc_sem so that we don't + * busyloop waiting for ip_alloc_sem to unlock + */ + ret = AOP_TRUNCATED_PAGE; + unlock_page(page); + unlock = 0; + down_read(&oi->ip_alloc_sem); + up_read(&oi->ip_alloc_sem); + 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); + 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) +{ + trace_ocfs2_writepage( + (unsigned long long)OCFS2_I(page->mapping->host)->ip_blkno, + page->index); + + return block_write_full_page(page, ocfs2_get_block, wbc); +} + +/* 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; +} + +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; + + trace_ocfs2_bmap((unsigned long long)OCFS2_I(inode)->ip_blkno, + (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; + + 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 in case of create. */ + BUG_ON(create && (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. 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, + int ret, + bool is_async) +{ + struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; + int level; + wait_queue_head_t *wq = ocfs2_ioend_wq(inode); + + /* this io's submitter should not have unlocked this before we could */ + BUG_ON(!ocfs2_iocb_is_rw_locked(iocb)); + + if (ocfs2_iocb_is_sem_locked(iocb)) + ocfs2_iocb_clear_sem_locked(iocb); + + if (ocfs2_iocb_is_unaligned_aio(iocb)) { + ocfs2_iocb_clear_unaligned_aio(iocb); + + if (atomic_dec_and_test(&OCFS2_I(inode)->ip_unaligned_aio) && + waitqueue_active(wq)) { + wake_up_all(wq); + } + } + + ocfs2_iocb_clear_rw_locked(iocb); + + level = ocfs2_iocb_rw_locked_level(iocb); + ocfs2_rw_unlock(inode, level); + + if (is_async) + aio_complete(iocb, ret, 0); + inode_dio_done(inode); +} + +/* + * 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; + + /* + * 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; + + return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, + iov, offset, nr_segs, + ocfs2_direct_IO_get_blocks, + ocfs2_dio_end_io, NULL, 0); +} + +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); + + 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); +} + +/* + * 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_write_begin(). 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. + */ + unsigned int w_num_pages; + struct page *w_pages[OCFS2_MAX_CTXT_PAGES]; + struct page *w_target_page; + + /* + * w_target_locked is used for page_mkwrite path indicating no unlocking + * against w_target_page in ocfs2_write_end_nolock. + */ + unsigned int w_target_locked:1; + + /* + * 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) +{ + int i; + + /* + * w_target_locked is only set to true in the page_mkwrite() case. + * The intent is to allow us to lock the target page from write_begin() + * to write_end(). The caller must hold a ref on w_target_page. + */ + if (wc->w_target_locked) { + BUG_ON(!wc->w_target_page); + for (i = 0; i < wc->w_num_pages; i++) { + if (wc->w_target_page == wc->w_pages[i]) { + wc->w_pages[i] = NULL; + break; + } + } + mark_page_accessed(wc->w_target_page); + page_cache_release(wc->w_target_page); + } + 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); + + /* treat the write as new if the a hole/lseek spanned across + * the page boundary. + */ + new = new | ((i_size_read(inode) <= page_offset(page)) && + (page_offset(page) <= user_pos)); + + 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, + unsigned user_len, int new, + struct page *mmap_page) +{ + int ret = 0, i; + unsigned long start, target_index, end_index, index; + struct inode *inode = mapping->host; + loff_t last_byte; + + 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 we're + * writing past i_size, we only need enough pages to cover the + * last page of the write. + */ + if (new) { + wc->w_num_pages = ocfs2_pages_per_cluster(inode->i_sb); + start = ocfs2_align_clusters_to_page_index(inode->i_sb, cpos); + /* + * We need the index *past* the last page we could possibly + * touch. This is the page past the end of the write or + * i_size, whichever is greater. + */ + last_byte = max(user_pos + user_len, i_size_read(inode)); + BUG_ON(last_byte < 1); + end_index = ((last_byte - 1) >> PAGE_CACHE_SHIFT) + 1; + if ((start + wc->w_num_pages) > end_index) + wc->w_num_pages = end_index - start; + } 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); + + /* Exit and let the caller retry */ + if (mmap_page->mapping != mapping) { + WARN_ON(mmap_page->mapping); + unlock_page(mmap_page); + ret = -EAGAIN; + goto out; + } + + page_cache_get(mmap_page); + wc->w_pages[i] = mmap_page; + wc->w_target_locked = true; + } 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: + if (ret) + wc->w_target_locked = false; + 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; + + trace_ocfs2_try_to_write_inline_data((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, + struct buffer_head *di_bh, + loff_t pos, unsigned len, + struct ocfs2_write_ctxt *wc) +{ + int ret; + loff_t newsize = pos + len; + + BUG_ON(ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))); + + if (newsize <= i_size_read(inode)) + return 0; + + ret = ocfs2_extend_no_holes(inode, di_bh, 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; +} + +static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh, + loff_t pos) +{ + int ret = 0; + + BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))); + if (pos > i_size_read(inode)) + ret = ocfs2_zero_extend(inode, di_bh, pos); + + return ret; +} + +/* + * Try to flush truncate logs if we can free enough clusters from it. + * As for return value, "< 0" means error, "0" no space and "1" means + * we have freed enough spaces and let the caller try to allocate again. + */ +static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb, + unsigned int needed) +{ + tid_t target; + int ret = 0; + unsigned int truncated_clusters; + + mutex_lock(&osb->osb_tl_inode->i_mutex); + truncated_clusters = osb->truncated_clusters; + mutex_unlock(&osb->osb_tl_inode->i_mutex); + + /* + * Check whether we can succeed in allocating if we free + * the truncate log. + */ + if (truncated_clusters < needed) + goto out; + + ret = ocfs2_flush_truncate_log(osb); + if (ret) { + mlog_errno(ret); + goto out; + } + + if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) { + jbd2_log_wait_commit(osb->journal->j_journal, target); + ret = 1; + } +out: + return ret; +} + +int ocfs2_write_begin_nolock(struct file *filp, + 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, clusters_need = 0; + 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; + int try_free = 1, ret1; + +try_again: + 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; + } + } + + if (ocfs2_sparse_alloc(osb)) + ret = ocfs2_zero_tail(inode, di_bh, pos); + else + ret = ocfs2_expand_nonsparse_inode(inode, di_bh, 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) { + clusters_need = wc->w_clen; + ret = ocfs2_refcount_cow(inode, filp, 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; + } + clusters_need += clusters_to_alloc; + + di = (struct ocfs2_dinode *)wc->w_di_bh->b_data; + + trace_ocfs2_write_begin_nolock( + (unsigned long long)OCFS2_I(inode)->ip_blkno, + (long long)i_size_read(inode), + le32_to_cpu(di->i_clusters), + pos, len, flags, mmap_page, + clusters_to_alloc, extents_to_split); + + /* + * 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. + */ + 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; + } + + if (data_ac) + data_ac->ac_resv = &OCFS2_I(inode)->ip_la_data_resv; + + 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) { + ret = dquot_alloc_space_nodirty(inode, + ocfs2_clusters_to_bytes(osb->sb, clusters_to_alloc)); + if (ret) + 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, len, + cluster_of_pages, mmap_page); + if (ret && ret != -EAGAIN) { + mlog_errno(ret); + goto out_quota; + } + + /* + * ocfs2_grab_pages_for_write() returns -EAGAIN if it could not lock + * the target page. In this case, we exit with no error and no target + * page. This will trigger the caller, page_mkwrite(), to re-try + * the operation. + */ + if (ret == -EAGAIN) { + BUG_ON(wc->w_target_page); + ret = 0; + 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) + dquot_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); + + if (ret == -ENOSPC && try_free) { + /* + * Try to free some truncate log so that we can have enough + * clusters to allocate. + */ + try_free = 0; + + ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need); + if (ret1 == 1) + goto try_again; + + if (ret1 < 0) + mlog_errno(ret1); + } + + 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(file, 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); + memcpy(di->id2.i_data.id_data + pos, kaddr + pos, *copied); + kunmap_atomic(kaddr); + + trace_ocfs2_write_end_inline( + (unsigned long long)OCFS2_I(inode)->ip_blkno, + (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, + .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, +}; |