diff options
Diffstat (limited to 'fs/ocfs2/alloc.c')
| -rw-r--r-- | fs/ocfs2/alloc.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c index 9a40603..98694a1 100644 --- a/fs/ocfs2/alloc.c +++ b/fs/ocfs2/alloc.c @@ -27,6 +27,7 @@ #include <linux/types.h> #include <linux/slab.h> #include <linux/highmem.h> +#include <linux/swap.h> #define MLOG_MASK_PREFIX ML_DISK_ALLOC #include <cluster/masklog.h> @@ -34,6 +35,7 @@ #include "ocfs2.h" #include "alloc.h" +#include "aops.h" #include "dlmglue.h" #include "extent_map.h" #include "inode.h" @@ -3342,6 +3344,228 @@ bail: return status; } +static int ocfs2_writeback_zero_func(handle_t *handle, struct buffer_head *bh) +{ + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + return 0; +} + +static int ocfs2_ordered_zero_func(handle_t *handle, struct buffer_head *bh) +{ + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + return ocfs2_journal_dirty_data(handle, bh); +} + +static void ocfs2_zero_cluster_pages(struct inode *inode, loff_t isize, + struct page **pages, int numpages, + u64 phys, handle_t *handle) +{ + int i, ret, partial = 0; + void *kaddr; + struct page *page; + unsigned int from, to = PAGE_CACHE_SIZE; + struct super_block *sb = inode->i_sb; + + BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb))); + + if (numpages == 0) + goto out; + + from = isize & (PAGE_CACHE_SIZE - 1); /* 1st page offset */ + if (PAGE_CACHE_SHIFT > OCFS2_SB(sb)->s_clustersize_bits) { + /* + * Since 'from' has been capped to a value below page + * size, this calculation won't be able to overflow + * 'to' + */ + to = ocfs2_align_bytes_to_clusters(sb, from); + + /* + * The truncate tail in this case should never contain + * more than one page at maximum. The loop below also + * assumes this. + */ + BUG_ON(numpages != 1); + } + + for(i = 0; i < numpages; i++) { + page = pages[i]; + + BUG_ON(from > PAGE_CACHE_SIZE); + BUG_ON(to > PAGE_CACHE_SIZE); + + ret = ocfs2_map_page_blocks(page, &phys, inode, from, to, 0); + if (ret) + mlog_errno(ret); + + kaddr = kmap_atomic(page, KM_USER0); + memset(kaddr + from, 0, to - from); + kunmap_atomic(kaddr, KM_USER0); + + /* + * Need to set the buffers we zero'd into uptodate + * here if they aren't - ocfs2_map_page_blocks() + * might've skipped some + */ + if (ocfs2_should_order_data(inode)) { + ret = walk_page_buffers(handle, + page_buffers(page), + from, to, &partial, + ocfs2_ordered_zero_func); + if (ret < 0) + mlog_errno(ret); + } else { + ret = walk_page_buffers(handle, page_buffers(page), + from, to, &partial, + ocfs2_writeback_zero_func); + if (ret < 0) + mlog_errno(ret); + } + + if (!partial) + SetPageUptodate(page); + + flush_dcache_page(page); + + /* + * Every page after the 1st one should be completely zero'd. + */ + from = 0; + } +out: + if (pages) { + for (i = 0; i < numpages; i++) { + page = pages[i]; + unlock_page(page); + mark_page_accessed(page); + page_cache_release(page); + } + } +} + +static int ocfs2_grab_eof_pages(struct inode *inode, loff_t isize, struct page **pages, + int *num, u64 *phys) +{ + int i, numpages = 0, ret = 0; + unsigned int csize = OCFS2_SB(inode->i_sb)->s_clustersize; + struct super_block *sb = inode->i_sb; + struct address_space *mapping = inode->i_mapping; + unsigned long index; + u64 next_cluster_bytes; + + BUG_ON(!ocfs2_sparse_alloc(OCFS2_SB(sb))); + + /* Cluster boundary, so we don't need to grab any pages. */ + if ((isize & (csize - 1)) == 0) + goto out; + + ret = ocfs2_extent_map_get_blocks(inode, isize >> sb->s_blocksize_bits, + phys, NULL); + if (ret) { + mlog_errno(ret); + goto out; + } + + /* Tail is a hole. */ + if (*phys == 0) + goto out; + + next_cluster_bytes = ocfs2_align_bytes_to_clusters(inode->i_sb, isize); + index = isize >> PAGE_CACHE_SHIFT; + do { + pages[numpages] = grab_cache_page(mapping, index); + if (!pages[numpages]) { + ret = -ENOMEM; + mlog_errno(ret); + goto out; + } + + numpages++; + index++; + } while (index < (next_cluster_bytes >> PAGE_CACHE_SHIFT)); + +out: + if (ret != 0) { + if (pages) { + for (i = 0; i < numpages; i++) { + if (pages[i]) { + unlock_page(pages[i]); + page_cache_release(pages[i]); + } + } + } + numpages = 0; + } + + *num = numpages; + + return ret; +} + +/* + * Zero the area past i_size but still within an allocated + * cluster. This avoids exposing nonzero data on subsequent file + * extends. + * + * We need to call this before i_size is updated on the inode because + * otherwise block_write_full_page() will skip writeout of pages past + * i_size. The new_i_size parameter is passed for this reason. + */ +int ocfs2_zero_tail_for_truncate(struct inode *inode, handle_t *handle, + u64 new_i_size) +{ + int ret, numpages; + struct page **pages = NULL; + u64 phys; + + /* + * File systems which don't support sparse files zero on every + * extend. + */ + if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) + return 0; + + pages = kcalloc(ocfs2_pages_per_cluster(inode->i_sb), + sizeof(struct page *), GFP_NOFS); + if (pages == NULL) { + ret = -ENOMEM; + mlog_errno(ret); + goto out; + } + + ret = ocfs2_grab_eof_pages(inode, new_i_size, pages, &numpages, &phys); + if (ret) { + mlog_errno(ret); + goto out; + } + + /* + * Truncate on an i_size boundary - nothing more to do. + */ + if (numpages == 0) + goto out; + + ocfs2_zero_cluster_pages(inode, new_i_size, pages, numpages, phys, + handle); + + /* + * Initiate writeout of the pages we zero'd here. We don't + * wait on them - the truncate_inode_pages() call later will + * do that for us. + */ + ret = filemap_fdatawrite(inode->i_mapping); + if (ret) + mlog_errno(ret); + +out: + if (pages) + kfree(pages); + + return ret; +} + /* * It is expected, that by the time you call this function, * inode->i_size and fe->i_size have been adjusted. |