diff options
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/alloc.c | 25 | ||||
| -rw-r--r-- | fs/ocfs2/alloc.h | 5 | ||||
| -rw-r--r-- | fs/ocfs2/aops.c | 4 | ||||
| -rw-r--r-- | fs/ocfs2/aops.h | 2 | ||||
| -rw-r--r-- | fs/ocfs2/refcounttree.c | 814 | ||||
| -rw-r--r-- | fs/ocfs2/refcounttree.h | 2 |
6 files changed, 841 insertions, 11 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 03438a677933..b8fc95d10630 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -6998,9 +6998,9 @@ static int ocfs2_zero_func(handle_t *handle, struct buffer_head *bh) return 0; } -static void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle, - unsigned int from, unsigned int to, - struct page *page, int zero, u64 *phys) +void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle, + unsigned int from, unsigned int to, + struct page *page, int zero, u64 *phys) { int ret, partial = 0; @@ -7068,20 +7068,16 @@ out: ocfs2_unlock_and_free_pages(pages, numpages); } -static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end, - struct page **pages, int *num) +int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end, + struct page **pages, int *num) { int numpages, ret = 0; - struct super_block *sb = inode->i_sb; struct address_space *mapping = inode->i_mapping; unsigned long index; loff_t last_page_bytes; BUG_ON(start > end); - BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits != - (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits); - numpages = 0; last_page_bytes = PAGE_ALIGN(end); index = start >> PAGE_CACHE_SHIFT; @@ -7109,6 +7105,17 @@ out: return ret; } +static int ocfs2_grab_eof_pages(struct inode *inode, loff_t start, loff_t end, + struct page **pages, int *num) +{ + struct super_block *sb = inode->i_sb; + + BUG_ON(start >> OCFS2_SB(sb)->s_clustersize_bits != + (end - 1) >> OCFS2_SB(sb)->s_clustersize_bits); + + return ocfs2_grab_pages(inode, start, end, pages, num); +} + /* * Zero the area past i_size but still within an allocated * cluster. This avoids exposing nonzero data on subsequent file diff --git a/fs/ocfs2/alloc.h b/fs/ocfs2/alloc.h index 19d5b88a93df..9c122d574464 100644 --- a/fs/ocfs2/alloc.h +++ b/fs/ocfs2/alloc.h @@ -271,6 +271,11 @@ static inline int ocfs2_is_empty_extent(struct ocfs2_extent_rec *rec) return !rec->e_leaf_clusters; } +int ocfs2_grab_pages(struct inode *inode, loff_t start, loff_t end, + struct page **pages, int *num); +void ocfs2_map_and_dirty_page(struct inode *inode, handle_t *handle, + unsigned int from, unsigned int to, + struct page *page, int zero, u64 *phys); /* * Structures which describe a path through a btree, and functions to * manipulate them. diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 15c594dfd951..fdad075fed61 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -126,8 +126,8 @@ bail: return err; } -static int ocfs2_get_block(struct inode *inode, sector_t iblock, - struct buffer_head *bh_result, int create) +int ocfs2_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) { int err = 0; unsigned int ext_flags; diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h index 503e49232e11..c48e93ffc513 100644 --- a/fs/ocfs2/aops.h +++ b/fs/ocfs2/aops.h @@ -57,6 +57,8 @@ int ocfs2_read_inline_data(struct inode *inode, struct page *page, struct buffer_head *di_bh); int ocfs2_size_fits_inline_data(struct buffer_head *di_bh, u64 new_size); +int ocfs2_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create); /* all ocfs2_dio_end_io()'s fault */ #define ocfs2_iocb_is_rw_locked(iocb) \ test_bit(0, (unsigned long *)&iocb->private) diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c index e72dbdd3b6e8..4e7df8b8fd4f 100644 --- a/fs/ocfs2/refcounttree.c +++ b/fs/ocfs2/refcounttree.c @@ -31,6 +31,27 @@ #include "sysfile.h" #include "dlmglue.h" #include "extent_map.h" +#include "aops.h" + +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/writeback.h> +#include <linux/pagevec.h> +#include <linux/swap.h> + +struct ocfs2_cow_context { + struct inode *inode; + u32 cow_start; + u32 cow_len; + struct ocfs2_extent_tree di_et; + struct ocfs2_caching_info *ref_ci; + struct buffer_head *ref_root_bh; + struct ocfs2_alloc_context *meta_ac; + struct ocfs2_alloc_context *data_ac; + struct ocfs2_cached_dealloc_ctxt dealloc; +}; static inline struct ocfs2_refcount_tree * cache_info_to_refcount(struct ocfs2_caching_info *ci) @@ -2404,3 +2425,796 @@ out: brelse(ref_root_bh); return ret; } + +#define MAX_CONTIG_BYTES 1048576 + +static inline unsigned int ocfs2_cow_contig_clusters(struct super_block *sb) +{ + return ocfs2_clusters_for_bytes(sb, MAX_CONTIG_BYTES); +} + +static inline unsigned int ocfs2_cow_contig_mask(struct super_block *sb) +{ + return ~(ocfs2_cow_contig_clusters(sb) - 1); +} + +/* + * Given an extent that starts at 'start' and an I/O that starts at 'cpos', + * find an offset (start + (n * contig_clusters)) that is closest to cpos + * while still being less than or equal to it. + * + * The goal is to break the extent at a multiple of contig_clusters. + */ +static inline unsigned int ocfs2_cow_align_start(struct super_block *sb, + unsigned int start, + unsigned int cpos) +{ + BUG_ON(start > cpos); + + return start + ((cpos - start) & ocfs2_cow_contig_mask(sb)); +} + +/* + * Given a cluster count of len, pad it out so that it is a multiple + * of contig_clusters. + */ +static inline unsigned int ocfs2_cow_align_length(struct super_block *sb, + unsigned int len) +{ + unsigned int padded = + (len + (ocfs2_cow_contig_clusters(sb) - 1)) & + ocfs2_cow_contig_mask(sb); + + /* Did we wrap? */ + if (padded < len) + padded = UINT_MAX; + + return padded; +} + +/* + * Calculate out the start and number of virtual clusters we need to to CoW. + * + * cpos is vitual start cluster position we want to do CoW in a + * file and write_len is the cluster length. + * + * Normal we will start CoW from the beginning of extent record cotaining cpos. + * We try to break up extents on boundaries of MAX_CONTIG_BYTES so that we + * get good I/O from the resulting extent tree. + */ +static int ocfs2_refcount_cal_cow_clusters(struct inode *inode, + struct buffer_head *di_bh, + u32 cpos, + u32 write_len, + u32 *cow_start, + u32 *cow_len) +{ + int ret = 0; + struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data; + struct ocfs2_extent_list *el = &di->id2.i_list; + int tree_height = le16_to_cpu(el->l_tree_depth), i; + struct buffer_head *eb_bh = NULL; + struct ocfs2_extent_block *eb = NULL; + struct ocfs2_extent_rec *rec; + unsigned int want_clusters, rec_end = 0; + int contig_clusters = ocfs2_cow_contig_clusters(inode->i_sb); + int leaf_clusters; + + if (tree_height > 0) { + ret = ocfs2_find_leaf(INODE_CACHE(inode), el, cpos, &eb_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + eb = (struct ocfs2_extent_block *) eb_bh->b_data; + el = &eb->h_list; + + if (el->l_tree_depth) { + ocfs2_error(inode->i_sb, + "Inode %lu has non zero tree depth in " + "leaf block %llu\n", inode->i_ino, + (unsigned long long)eb_bh->b_blocknr); + ret = -EROFS; + goto out; + } + } + + *cow_len = 0; + for (i = 0; i < le16_to_cpu(el->l_next_free_rec); i++) { + rec = &el->l_recs[i]; + + if (ocfs2_is_empty_extent(rec)) { + mlog_bug_on_msg(i != 0, "Inode %lu has empty record in " + "index %d\n", inode->i_ino, i); + continue; + } + + if (le32_to_cpu(rec->e_cpos) + + le16_to_cpu(rec->e_leaf_clusters) <= cpos) + continue; + + if (*cow_len == 0) { + /* + * We should find a refcounted record in the + * first pass. + */ + BUG_ON(!(rec->e_flags & OCFS2_EXT_REFCOUNTED)); + *cow_start = le32_to_cpu(rec->e_cpos); + } + + /* + * If we encounter a hole or a non-refcounted record, + * stop the search. + */ + if ((!(rec->e_flags & OCFS2_EXT_REFCOUNTED)) || + (*cow_len && rec_end != le32_to_cpu(rec->e_cpos))) + break; + + leaf_clusters = le16_to_cpu(rec->e_leaf_clusters); + rec_end = le32_to_cpu(rec->e_cpos) + leaf_clusters; + + /* + * How many clusters do we actually need from + * this extent? First we see how many we actually + * need to complete the write. If that's smaller + * than contig_clusters, we try for contig_clusters. + */ + if (!*cow_len) + want_clusters = write_len; + else + want_clusters = (cpos + write_len) - + (*cow_start + *cow_len); + if (want_clusters < contig_clusters) + want_clusters = contig_clusters; + + /* + * If the write does not cover the whole extent, we + * need to calculate how we're going to split the extent. + * We try to do it on contig_clusters boundaries. + * + * Any extent smaller than contig_clusters will be + * CoWed in its entirety. + */ + if (leaf_clusters <= contig_clusters) + *cow_len += leaf_clusters; + else if (*cow_len || (*cow_start == cpos)) { + /* + * This extent needs to be CoW'd from its + * beginning, so all we have to do is compute + * how many clusters to grab. We align + * want_clusters to the edge of contig_clusters + * to get better I/O. + */ + want_clusters = ocfs2_cow_align_length(inode->i_sb, + want_clusters); + + if (leaf_clusters < want_clusters) + *cow_len += leaf_clusters; + else + *cow_len += want_clusters; + } else if ((*cow_start + contig_clusters) >= + (cpos + write_len)) { + /* + * Breaking off contig_clusters at the front + * of the extent will cover our write. That's + * easy. + */ + *cow_len = contig_clusters; + } else if ((rec_end - cpos) <= contig_clusters) { + /* + * Breaking off contig_clusters at the tail of + * this extent will cover cpos. + */ + *cow_start = rec_end - contig_clusters; + *cow_len = contig_clusters; + } else if ((rec_end - cpos) <= want_clusters) { + /* + * While we can't fit the entire write in this + * extent, we know that the write goes from cpos + * to the end of the extent. Break that off. + * We try to break it at some multiple of + * contig_clusters from the front of the extent. + * Failing that (ie, cpos is within + * contig_clusters of the front), we'll CoW the + * entire extent. + */ + *cow_start = ocfs2_cow_align_start(inode->i_sb, + *cow_start, cpos); + *cow_len = rec_end - *cow_start; + } else { + /* + * Ok, the entire write lives in the middle of + * this extent. Let's try to slice the extent up + * nicely. Optimally, our CoW region starts at + * m*contig_clusters from the beginning of the + * extent and goes for n*contig_clusters, + * covering the entire write. + */ + *cow_start = ocfs2_cow_align_start(inode->i_sb, + *cow_start, cpos); + + want_clusters = (cpos + write_len) - *cow_start; + want_clusters = ocfs2_cow_align_length(inode->i_sb, + want_clusters); + if (*cow_start + want_clusters <= rec_end) + *cow_len = want_clusters; + else + *cow_len = rec_end - *cow_start; + } + + /* Have we covered our entire write yet? */ + if ((*cow_start + *cow_len) >= (cpos + write_len)) + break; + + /* + * If we reach the end of the extent block and don't get enough + * clusters, continue with the next extent block if possible. + */ + if (i + 1 == le16_to_cpu(el->l_next_free_rec) && + eb && eb->h_next_leaf_blk) { + brelse(eb_bh); + eb_bh = NULL; + + ret = ocfs2_read_extent_block(INODE_CACHE(inode), + le64_to_cpu(eb->h_next_leaf_blk), + &eb_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + eb = (struct ocfs2_extent_block *) eb_bh->b_data; + el = &eb->h_list; + i = -1; + } + } + +out: + brelse(eb_bh); + return ret; +} + +/* + * Prepare meta_ac, data_ac and calculate credits when we want to add some + * num_clusters in data_tree "et" and change the refcount for the old + * clusters(starting form p_cluster) in the refcount tree. + * + * Note: + * 1. since we may split the old tree, so we at most will need num_clusters + 2 + * more new leaf records. + * 2. In some case, we may not need to reserve new clusters(e.g, reflink), so + * just give data_ac = NULL. + */ +static int ocfs2_lock_refcount_allocators(struct super_block *sb, + u32 p_cluster, u32 num_clusters, + struct ocfs2_extent_tree *et, + struct ocfs2_caching_info *ref_ci, + struct buffer_head *ref_root_bh, + struct ocfs2_alloc_context **meta_ac, + struct ocfs2_alloc_context **data_ac, + int *credits) +{ + int ret = 0, meta_add = 0; + int num_free_extents = ocfs2_num_free_extents(OCFS2_SB(sb), et); + + if (num_free_extents < 0) { + ret = num_free_extents; + mlog_errno(ret); + goto out; + } + + if (num_free_extents < num_clusters + 2) + meta_add = + ocfs2_extend_meta_needed(et->et_root_el); + + *credits += ocfs2_calc_extend_credits(sb, et->et_root_el, + num_clusters + 2); + + ret = ocfs2_calc_refcount_meta_credits(sb, ref_ci, ref_root_bh, + p_cluster, num_clusters, + &meta_add, credits); + if (ret) { + mlog_errno(ret); + goto out; + } + + mlog(0, "reserve new metadata %d, clusters %u, credits = %d\n", + meta_add, num_clusters, *credits); + ret = ocfs2_reserve_new_metadata_blocks(OCFS2_SB(sb), meta_add, + meta_ac); + if (ret) { + mlog_errno(ret); + goto out; + } + + if (data_ac) { + ret = ocfs2_reserve_clusters(OCFS2_SB(sb), num_clusters, + data_ac); + if (ret) + mlog_errno(ret); + } + +out: + if (ret) { + if (*meta_ac) { + ocfs2_free_alloc_context(*meta_ac); + *meta_ac = NULL; + } + } + + return ret; +} + +static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh) +{ + BUG_ON(buffer_dirty(bh)); + + clear_buffer_mapped(bh); + + return 0; +} + +static int ocfs2_duplicate_clusters(handle_t *handle, + struct ocfs2_cow_context *context, + u32 cpos, u32 old_cluster, + u32 new_cluster, u32 new_len) +{ + int ret = 0, partial; + struct ocfs2_caching_info *ci = context->di_et.et_ci; + struct super_block *sb = ocfs2_metadata_cache_get_super(ci); + u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster); + struct page *page; + pgoff_t page_index; + unsigned int from, to; + loff_t offset, end, map_end; + struct address_space *mapping = context->inode->i_mapping; + + mlog(0, "old_cluster %u, new %u, len %u at offset %u\n", old_cluster, + new_cluster, new_len, cpos); + + offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits; + end = offset + (new_len << OCFS2_SB(sb)->s_clustersize_bits); + + while (offset < end) { + page_index = offset >> PAGE_CACHE_SHIFT; + map_end = (page_index + 1) << PAGE_CACHE_SHIFT; + if (map_end > end) + map_end = end; + + /* from, to is the offset within the page. */ + from = offset & (PAGE_CACHE_SIZE - 1); + to = PAGE_CACHE_SIZE; + if (map_end & (PAGE_CACHE_SIZE - 1)) + to = map_end & (PAGE_CACHE_SIZE - 1); + + page = grab_cache_page(mapping, page_index); + + /* This page can't be dirtied before we CoW it out. */ + BUG_ON(PageDirty(page)); + + if (!PageUptodate(page)) { + ret = block_read_full_page(page, ocfs2_get_block); + if (ret) { + mlog_errno(ret); + goto unlock; + } + lock_page(page); + } + + if (page_has_buffers(page)) { + ret = walk_page_buffers(handle, page_buffers(page), + from, to, &partial, + ocfs2_clear_cow_buffer); + if (ret) { + mlog_errno(ret); + goto unlock; + } + } + + ocfs2_map_and_dirty_page(context->inode, + handle, from, to, + page, 0, &new_block); + mark_page_accessed(page); +unlock: + unlock_page(page); + page_cache_release(page); + page = NULL; + offset = map_end; + if (ret) + break; + } + + return ret; +} + +static int ocfs2_clear_ext_refcount(handle_t *handle, + struct ocfs2_extent_tree *et, + u32 cpos, u32 p_cluster, u32 len, + unsigned int ext_flags, + struct ocfs2_alloc_context *meta_ac, + struct ocfs2_cached_dealloc_ctxt *dealloc) +{ + int ret, index; + struct ocfs2_extent_rec replace_rec; + struct ocfs2_path *path = NULL; + struct ocfs2_extent_list *el; + struct super_block *sb = ocfs2_metadata_cache_get_super(et->et_ci); + u64 ino = ocfs2_metadata_cache_owner(et->et_ci); + + mlog(0, "inode %llu cpos %u, len %u, p_cluster %u, ext_flags %u\n", + (unsigned long long)ino, cpos, len, p_cluster, ext_flags); + + memset(&replace_rec, 0, sizeof(replace_rec)); + replace_rec.e_cpos = cpu_to_le32(cpos); + replace_rec.e_leaf_clusters = cpu_to_le16(len); + replace_rec.e_blkno = cpu_to_le64(ocfs2_clusters_to_blocks(sb, + p_cluster)); + replace_rec.e_flags = ext_flags; + replace_rec.e_flags &= ~OCFS2_EXT_REFCOUNTED; + + path = ocfs2_new_path_from_et(et); + if (!path) { + ret = -ENOMEM; + mlog_errno(ret); + goto out; + } + + ret = ocfs2_find_path(et->et_ci, path, cpos); + if (ret) { + mlog_errno(ret); + goto out; + } + + el = path_leaf_el(path); + + index = ocfs2_search_extent_list(el, cpos); + if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) { + ocfs2_error(sb, + "Inode %llu has an extent at cpos %u which can no " + "longer be found.\n", + (unsigned long long)ino, cpos); + ret = -EROFS; + goto out; + } + + ret = ocfs2_split_extent(handle, et, path, index, + &replace_rec, meta_ac, dealloc); + if (ret) + mlog_errno(ret); + +out: + ocfs2_free_path(path); + return ret; +} + +static int ocfs2_replace_clusters(handle_t *handle, + struct ocfs2_cow_context *context, + u32 cpos, u32 old, + u32 new, u32 len, + unsigned int ext_flags) +{ + int ret; + struct ocfs2_caching_info *ci = context->di_et.et_ci; + u64 ino = ocfs2_metadata_cache_owner(ci); + + mlog(0, "inode %llu, cpos %u, old %u, new %u, len %u, ext_flags %u\n", + (unsigned long long)ino, cpos, old, new, len, ext_flags); + + /*If the old clusters is unwritten, no need to duplicate. */ + if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) { + ret = ocfs2_duplicate_clusters(handle, context, cpos, + old, new, len); + if (ret) { + mlog_errno(ret); + goto out; + } + } + + ret = ocfs2_clear_ext_refcount(handle, &context->di_et, + cpos, new, len, ext_flags, + context->meta_ac, &context->dealloc); + if (ret) + mlog_errno(ret); +out: + return ret; +} + +static int ocfs2_cow_sync_writeback(struct super_block *sb, + struct ocfs2_cow_context *context, + u32 cpos, u32 num_clusters) +{ + int ret = 0; + loff_t offset, end, map_end; + pgoff_t page_index; + struct page *page; + + if (ocfs2_should_order_data(context->inode)) + return 0; + + offset = ((loff_t)cpos) << OCFS2_SB(sb)->s_clustersize_bits; + end = offset + (num_clusters << OCFS2_SB(sb)->s_clustersize_bits); + + ret = filemap_fdatawrite_range(context->inode->i_mapping, + offset, end - 1); + if (ret < 0) { + mlog_errno(ret); + return ret; + } + + while (offset < end) { + page_index = offset >> PAGE_CACHE_SHIFT; + map_end = (page_index + 1) << PAGE_CACHE_SHIFT; + if (map_end > end) + map_end = end; + + page = grab_cache_page(context->inode->i_mapping, page_index); + BUG_ON(!page); + + wait_on_page_writeback(page); + if (PageError(page)) { + ret = -EIO; + mlog_errno(ret); + } else + mark_page_accessed(page); + + unlock_page(page); + page_cache_release(page); + page = NULL; + offset = map_end; + if (ret) + break; + } + + return ret; +} + +static int ocfs2_make_clusters_writable(struct super_block *sb, + struct ocfs2_cow_context *context, + u32 cpos, u32 p_cluster, + u32 num_clusters, unsigned int e_flags) +{ + int ret, credits = 0; + u32 new_bit, new_len; + struct ocfs2_super *osb = OCFS2_SB(sb); + handle_t *handle; + + ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters, + &context->di_et, + context->ref_ci, + context->ref_root_bh, + &context->meta_ac, + &context->data_ac, &credits); + if (ret) { + mlog_errno(ret); + return ret; + } + + handle = ocfs2_start_trans(osb, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + mlog_errno(ret); + goto out; + } + + while (num_clusters) { + ret = __ocfs2_claim_clusters(osb, handle, context->data_ac, + 1, num_clusters, + &new_bit, &new_len); + if (ret) { + mlog_errno(ret); + goto out_commit; + } + + ret = ocfs2_replace_clusters(handle, context, + cpos, p_cluster, new_bit, + new_len, e_flags); + if (ret) { + mlog_errno(ret); + goto out_commit; + } + + cpos += new_len; + p_cluster += new_len; + num_clusters -= new_len; + } + + ret = __ocfs2_decrease_refcount(handle, context->ref_ci, + context->ref_root_bh, + p_cluster, num_clusters, + context->meta_ac, + &context->dealloc); + if (ret) { + mlog_errno(ret); + goto out_commit; + } + + /* + * Here we should write the new page out first if we are + * in write-back mode. + */ + ret = ocfs2_cow_sync_writeback(sb, context, cpos, num_clusters); + if (ret) + mlog_errno(ret); + +out_commit: + ocfs2_commit_trans(osb, handle); + +out: + if (context->data_ac) { + ocfs2_free_alloc_context(context->data_ac); + context->data_ac = NULL; + } + if (context->meta_ac) { + ocfs2_free_alloc_context(context->meta_ac); + context->meta_ac = NULL; + } + + return ret; +} + +static int ocfs2_replace_cow(struct inode *inode, + struct buffer_head *di_bh, + struct buffer_head *ref_root_bh, + struct ocfs2_caching_info *ref_ci, + u32 cow_start, u32 cow_len) +{ + int ret = 0; + u32 p_cluster, num_clusters, start = cow_start; + unsigned int ext_flags; + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + struct ocfs2_cow_context *context; + + if (!ocfs2_refcount_tree(OCFS2_SB(inode->i_sb))) { + ocfs2_error(inode->i_sb, "Inode %lu want to use refcount " + "tree, but the feature bit is not set in the " + "super block.", inode->i_ino); + return -EROFS; + } + + context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS); + if (!context) { + ret = -ENOMEM; + mlog_errno(ret); + return ret; + } + + context->inode = inode; + context->cow_start = cow_start; + context->cow_len = cow_len; + context->ref_ci = ref_ci; + context->ref_root_bh = ref_root_bh; + + ocfs2_init_dealloc_ctxt(&context->dealloc); + ocfs2_init_dinode_extent_tree(&context->di_et, + INODE_CACHE(inode), di_bh); + + while (cow_len) { + ret = ocfs2_get_clusters(inode, cow_start, &p_cluster, + &num_clusters, &ext_flags); + if (ret) { + mlog_errno(ret); + break; + } + + BUG_ON(!(ext_flags & OCFS2_EXT_REFCOUNTED)); + + if (cow_len < num_clusters) + num_clusters = cow_len; + + ret = ocfs2_make_clusters_writable(inode->i_sb, context, + cow_start, p_cluster, + num_clusters, ext_flags); + if (ret) { + mlog_errno(ret); + break; + } + + cow_len -= num_clusters; + cow_start += num_clusters; + } + + + /* + * truncate the extent map here since no matter whether we meet with + * any error during the action, we shouldn't trust cached extent map + * any more. + */ + ocfs2_extent_map_trunc(inode, start); + + if (ocfs2_dealloc_has_cluster(&context->dealloc)) { + ocfs2_schedule_truncate_log_flush(osb, 1); + ocfs2_run_deallocs(osb, &context->dealloc); + } + + kfree(context); + return ret; +} + +/* + * Starting at cpos, try to CoW write_len clusters. + * This will stop when it runs into a hole or an unrefcounted extent. + */ +static int ocfs2_refcount_cow_hunk(struct inode *inode, + struct buffer_head *di_bh, + u32 cpos, u32 write_len) +{ + int ret; + u32 cow_start = 0, cow_len = 0; + struct ocfs2_inode_info *oi = OCFS2_I(inode); + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data; + struct buffer_head *ref_root_bh = NULL; + struct ocfs2_refcount_tree *ref_tree; + + BUG_ON(!(oi->ip_dyn_features & OCFS2_HAS_REFCOUNT_FL)); + + ret = ocfs2_refcount_cal_cow_clusters(inode, di_bh, cpos, write_len, + &cow_start, &cow_len); + if (ret) { + mlog_errno(ret); + goto out; + } + mlog(0, "CoW inode %lu, cpos %u, write_len %u, cow_start %u, " + "cow_len %u\n", inode->i_ino, + cpos, write_len, cow_start, cow_len); + + BUG_ON(cow_len == 0); + + ret = ocfs2_lock_refcount_tree(osb, le64_to_cpu(di->i_refcount_loc), + 1, &ref_tree, &ref_root_bh); + if (ret) { + mlog_errno(ret); + goto out; + } + + ret = ocfs2_replace_cow(inode, di_bh, ref_root_bh, &ref_tree->rf_ci, + cow_start, cow_len); + if (ret) + mlog_errno(ret); + + ocfs2_unlock_refcount_tree(osb, ref_tree, 1); + brelse(ref_root_bh); +out: + return ret; +} + +/* + * CoW any and all clusters between cpos and cpos+write_len. + * If this returns successfully, all clusters between cpos and + * cpos+write_len are safe to modify. + */ +int ocfs2_refcount_cow(struct inode *inode, + struct buffer_head *di_bh, + u32 cpos, u32 write_len) +{ + int ret = 0; + u32 p_cluster, num_clusters; + unsigned int ext_flags; + + while (write_len) { + ret = ocfs2_get_clusters(inode, cpos, &p_cluster, + &num_clusters, &ext_flags); + if (ret) { + mlog_errno(ret); + break; + } + + if (write_len < num_clusters) + num_clusters = write_len; + + if (ext_flags & OCFS2_EXT_REFCOUNTED) { + ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos, + num_clusters); + if (ret) { + mlog_errno(ret); + break; + } + } + + write_len -= num_clusters; + cpos += num_clusters; + } + + return ret; +} diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h index b8c9ed7dc383..9960878134df 100644 --- a/fs/ocfs2/refcounttree.h +++ b/fs/ocfs2/refcounttree.h @@ -51,4 +51,6 @@ int ocfs2_prepare_refcount_change_for_del(struct inode *inode, u32 clusters, int *credits, struct ocfs2_alloc_context **meta_ac); +int ocfs2_refcount_cow(struct inode *inode, struct buffer_head *di_bh, + u32 cpos, u32 write_len); #endif /* OCFS2_REFCOUNTTREE_H */ |