diff options
Diffstat (limited to 'fs/ocfs2/file.c')
| -rw-r--r-- | fs/ocfs2/file.c | 119 |
1 files changed, 96 insertions, 23 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 6745086da6f..3e21ad9a6dd 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -425,6 +425,7 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, struct inode *inode, u32 *logical_offset, u32 clusters_to_add, + int mark_unwritten, struct buffer_head *fe_bh, handle_t *handle, struct ocfs2_alloc_context *data_ac, @@ -437,9 +438,13 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, enum ocfs2_alloc_restarted reason = RESTART_NONE; u32 bit_off, num_bits; u64 block; + u8 flags = 0; BUG_ON(!clusters_to_add); + if (mark_unwritten) + flags = OCFS2_EXT_UNWRITTEN; + free_extents = ocfs2_num_free_extents(osb, inode, fe); if (free_extents < 0) { status = free_extents; @@ -489,7 +494,7 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, num_bits, bit_off, (unsigned long long)OCFS2_I(inode)->ip_blkno); status = ocfs2_insert_extent(osb, handle, inode, fe_bh, *logical_offset, block, num_bits, - meta_ac); + flags, meta_ac); if (status < 0) { mlog_errno(status); goto leave; @@ -522,9 +527,11 @@ leave: * For a given allocation, determine which allocators will need to be * accessed, and lock them, reserving the appropriate number of bits. * - * Called from ocfs2_extend_allocation() for file systems which don't - * support holes, and from ocfs2_write() for file systems which - * understand sparse inodes. + * Sparse file systems call this from ocfs2_write_begin_nolock() + * and ocfs2_allocate_unwritten_extents(). + * + * File systems which don't support holes call this from + * ocfs2_extend_allocation(). */ int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di, u32 clusters_to_add, u32 extents_to_split, @@ -595,14 +602,13 @@ out: return ret; } -static int ocfs2_extend_allocation(struct inode *inode, - u32 clusters_to_add) +static int __ocfs2_extend_allocation(struct inode *inode, u32 logical_start, + u32 clusters_to_add, int mark_unwritten) { int status = 0; int restart_func = 0; - int drop_alloc_sem = 0; int credits; - u32 prev_clusters, logical_start; + u32 prev_clusters; struct buffer_head *bh = NULL; struct ocfs2_dinode *fe = NULL; handle_t *handle = NULL; @@ -617,7 +623,7 @@ static int ocfs2_extend_allocation(struct inode *inode, * This function only exists for file systems which don't * support holes. */ - BUG_ON(ocfs2_sparse_alloc(osb)); + BUG_ON(mark_unwritten && !ocfs2_sparse_alloc(osb)); status = ocfs2_read_block(osb, OCFS2_I(inode)->ip_blkno, &bh, OCFS2_BH_CACHED, inode); @@ -633,18 +639,9 @@ static int ocfs2_extend_allocation(struct inode *inode, goto leave; } - logical_start = OCFS2_I(inode)->ip_clusters; - restart_all: BUG_ON(le32_to_cpu(fe->i_clusters) != OCFS2_I(inode)->ip_clusters); - /* blocks peope in read/write from reading our allocation - * until we're done changing it. We depend on i_mutex to block - * other extend/truncate calls while we're here. Ordering wrt - * start_trans is important here -- always do it before! */ - down_write(&OCFS2_I(inode)->ip_alloc_sem); - drop_alloc_sem = 1; - status = ocfs2_lock_allocators(inode, fe, clusters_to_add, 0, &data_ac, &meta_ac); if (status) { @@ -678,6 +675,7 @@ restarted_transaction: inode, &logical_start, clusters_to_add, + mark_unwritten, bh, handle, data_ac, @@ -730,10 +728,6 @@ restarted_transaction: OCFS2_I(inode)->ip_clusters, i_size_read(inode)); leave: - if (drop_alloc_sem) { - up_write(&OCFS2_I(inode)->ip_alloc_sem); - drop_alloc_sem = 0; - } if (handle) { ocfs2_commit_trans(osb, handle); handle = NULL; @@ -759,6 +753,25 @@ leave: return status; } +static int ocfs2_extend_allocation(struct inode *inode, u32 logical_start, + u32 clusters_to_add, int mark_unwritten) +{ + int ret; + + /* + * The alloc sem blocks peope in read/write from reading our + * allocation until we're done changing it. We depend on + * i_mutex to block other extend/truncate calls while we're + * here. + */ + down_write(&OCFS2_I(inode)->ip_alloc_sem); + ret = __ocfs2_extend_allocation(inode, logical_start, clusters_to_add, + mark_unwritten); + up_write(&OCFS2_I(inode)->ip_alloc_sem); + + return ret; +} + /* Some parts of this taken from generic_cont_expand, which turned out * to be too fragile to do exactly what we need without us having to * worry about recursive locking in ->prepare_write() and @@ -900,7 +913,9 @@ static int ocfs2_extend_file(struct inode *inode, } if (clusters_to_add) { - ret = ocfs2_extend_allocation(inode, clusters_to_add); + ret = ocfs2_extend_allocation(inode, + OCFS2_I(inode)->ip_clusters, + clusters_to_add, 0); if (ret < 0) { mlog_errno(ret); goto out_unlock; @@ -1176,6 +1191,64 @@ out: return ret; } +/* + * Allocate enough extents to cover the region starting at byte offset + * start for len bytes. Existing extents are skipped, any extents + * added are marked as "unwritten". + */ +static int ocfs2_allocate_unwritten_extents(struct inode *inode, + u64 start, u64 len) +{ + int ret; + u32 cpos, phys_cpos, clusters, alloc_size; + + /* + * We consider both start and len to be inclusive. + */ + cpos = start >> OCFS2_SB(inode->i_sb)->s_clustersize_bits; + clusters = ocfs2_clusters_for_bytes(inode->i_sb, start + len); + clusters -= cpos; + + while (clusters) { + ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, + &alloc_size, NULL); + if (ret) { + mlog_errno(ret); + goto out; + } + + /* + * Hole or existing extent len can be arbitrary, so + * cap it to our own allocation request. + */ + if (alloc_size > clusters) + alloc_size = clusters; + + if (phys_cpos) { + /* + * We already have an allocation at this + * region so we can safely skip it. + */ + goto next; + } + + ret = __ocfs2_extend_allocation(inode, cpos, alloc_size, 1); + if (ret) { + if (ret != -ENOSPC) + mlog_errno(ret); + goto out; + } + +next: + cpos += alloc_size; + clusters -= alloc_size; + } + + ret = 0; +out: + return ret; +} + static int ocfs2_prepare_inode_for_write(struct dentry *dentry, loff_t *ppos, size_t count, |