diff options
| -rw-r--r-- | fs/gfs2/ops_address.c | 211 |
1 files changed, 127 insertions, 84 deletions
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c index 873a511..9679f8b 100644 --- a/fs/gfs2/ops_address.c +++ b/fs/gfs2/ops_address.c @@ -17,6 +17,7 @@ #include <linux/mpage.h> #include <linux/fs.h> #include <linux/writeback.h> +#include <linux/swap.h> #include <linux/gfs2_ondisk.h> #include <linux/lm_interface.h> @@ -349,45 +350,49 @@ out_unlock: } /** - * gfs2_prepare_write - Prepare to write a page to a file + * gfs2_write_begin - Begin to write to a file * @file: The file to write to - * @page: The page which is to be prepared for writing - * @from: From (byte range within page) - * @to: To (byte range within page) + * @mapping: The mapping in which to write + * @pos: The file offset at which to start writing + * @len: Length of the write + * @flags: Various flags + * @pagep: Pointer to return the page + * @fsdata: Pointer to return fs data (unused by GFS2) * * Returns: errno */ -static int gfs2_prepare_write(struct file *file, struct page *page, - unsigned from, unsigned to) +static int gfs2_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) { - struct gfs2_inode *ip = GFS2_I(page->mapping->host); - struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); + struct gfs2_inode *ip = GFS2_I(mapping->host); + struct gfs2_sbd *sdp = GFS2_SB(mapping->host); unsigned int data_blocks, ind_blocks, rblocks; int alloc_required; int error = 0; - loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + from; - loff_t end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; struct gfs2_alloc *al; - unsigned int write_len = to - from; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + unsigned from = pos & (PAGE_CACHE_SIZE - 1); + unsigned to = from + len; + struct page *page; - - gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|LM_FLAG_TRY_1CB, &ip->i_gh); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh); error = gfs2_glock_nq_atime(&ip->i_gh); - if (unlikely(error)) { - if (error == GLR_TRYFAILED) { - unlock_page(page); - error = AOP_TRUNCATED_PAGE; - yield(); - } + if (unlikely(error)) goto out_uninit; - } - gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks); + error = -ENOMEM; + page = __grab_cache_page(mapping, index); + *pagep = page; + if (!page) + goto out_unlock; + + gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks); - error = gfs2_write_alloc_required(ip, pos, write_len, &alloc_required); + error = gfs2_write_alloc_required(ip, pos, len, &alloc_required); if (error) - goto out_unlock; + goto out_putpage; ip->i_alloc.al_requested = 0; @@ -420,7 +425,7 @@ static int gfs2_prepare_write(struct file *file, struct page *page, goto out_trans_fail; if (gfs2_is_stuffed(ip)) { - if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { + if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { error = gfs2_unstuff_dinode(ip, page); if (error == 0) goto prepare_write; @@ -443,6 +448,10 @@ out_qunlock: out_alloc_put: gfs2_alloc_put(ip); } +out_putpage: + page_cache_release(page); + if (pos + len > ip->i_inode.i_size) + vmtruncate(&ip->i_inode, ip->i_inode.i_size); out_unlock: gfs2_glock_dq_m(1, &ip->i_gh); out_uninit: @@ -478,65 +487,117 @@ static void adjust_fs_space(struct inode *inode) } /** - * gfs2_commit_write - Commit write to a file + * gfs2_stuffed_write_end - Write end for stuffed files + * @inode: The inode + * @dibh: The buffer_head containing the on-disk inode + * @pos: The file position + * @len: The length of the write + * @copied: How much was actually copied by the VFS + * @page: The page + * + * This copies the data from the page into the inode block after + * the inode data structure itself. + * + * Returns: errno + */ +static int gfs2_stuffed_write_end(struct inode *inode, struct buffer_head *dibh, + loff_t pos, unsigned len, unsigned copied, + struct page *page) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + u64 to = pos + copied; + void *kaddr; + unsigned char *buf = dibh->b_data + sizeof(struct gfs2_dinode); + struct gfs2_dinode *di = (struct gfs2_dinode *)dibh->b_data; + + BUG_ON((pos + len) > (dibh->b_size - sizeof(struct gfs2_dinode))); + kaddr = kmap_atomic(page, KM_USER0); + memcpy(buf + pos, kaddr + pos, copied); + memset(kaddr + pos + copied, 0, len - copied); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); + + if (!PageUptodate(page)) + SetPageUptodate(page); + unlock_page(page); + page_cache_release(page); + + if (inode->i_size < to) { + i_size_write(inode, to); + ip->i_di.di_size = inode->i_size; + di->di_size = cpu_to_be64(inode->i_size); + mark_inode_dirty(inode); + } + + if (inode == sdp->sd_rindex) + adjust_fs_space(inode); + + brelse(dibh); + gfs2_trans_end(sdp); + gfs2_glock_dq(&ip->i_gh); + gfs2_holder_uninit(&ip->i_gh); + return copied; +} + +/** + * gfs2_write_end * @file: The file to write to - * @page: The page containing the data - * @from: From (byte range within page) - * @to: To (byte range within page) + * @mapping: The address space to write to + * @pos: The file position + * @len: The length of the data + * @copied: + * @page: The page that has been written + * @fsdata: The fsdata (unused in GFS2) + * + * The main write_end function for GFS2. We have a separate one for + * stuffed files as they are slightly different, otherwise we just + * put our locking around the VFS provided functions. * * Returns: errno */ -static int gfs2_commit_write(struct file *file, struct page *page, - unsigned from, unsigned to) +static int gfs2_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) { struct inode *inode = page->mapping->host; struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_sbd *sdp = GFS2_SB(inode); - int error = -EOPNOTSUPP; struct buffer_head *dibh; struct gfs2_alloc *al = &ip->i_alloc; struct gfs2_dinode *di; + unsigned int from = pos & (PAGE_CACHE_SIZE - 1); + unsigned int to = from + len; + int ret; - if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl))) - goto fail_nounlock; + BUG_ON(gfs2_glock_is_locked_by_me(ip->i_gl) == 0); - error = gfs2_meta_inode_buffer(ip, &dibh); - if (error) - goto fail_endtrans; + ret = gfs2_meta_inode_buffer(ip, &dibh); + if (unlikely(ret)) { + unlock_page(page); + page_cache_release(page); + goto failed; + } gfs2_trans_add_bh(ip->i_gl, dibh, 1); - di = (struct gfs2_dinode *)dibh->b_data; - - if (gfs2_is_stuffed(ip)) { - u64 file_size; - void *kaddr; - file_size = ((u64)page->index << PAGE_CACHE_SHIFT) + to; + if (gfs2_is_stuffed(ip)) + return gfs2_stuffed_write_end(inode, dibh, pos, len, copied, page); - kaddr = kmap_atomic(page, KM_USER0); - memcpy(dibh->b_data + sizeof(struct gfs2_dinode) + from, - kaddr + from, to - from); - kunmap_atomic(kaddr, KM_USER0); + if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || gfs2_is_jdata(ip)) + gfs2_page_add_databufs(ip, page, from, to); - SetPageUptodate(page); + ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata); - if (inode->i_size < file_size) { - i_size_write(inode, file_size); + if (likely(ret >= 0)) { + copied = ret; + if ((pos + copied) > inode->i_size) { + di = (struct gfs2_dinode *)dibh->b_data; + ip->i_di.di_size = inode->i_size; + di->di_size = cpu_to_be64(inode->i_size); mark_inode_dirty(inode); } - } else { - if (sdp->sd_args.ar_data == GFS2_DATA_ORDERED || - gfs2_is_jdata(ip)) - gfs2_page_add_databufs(ip, page, from, to); - error = generic_commit_write(file, page, from, to); - if (error) - goto fail; - } - - if (ip->i_di.di_size < inode->i_size) { - ip->i_di.di_size = inode->i_size; - di->di_size = cpu_to_be64(inode->i_size); } if (inode == sdp->sd_rindex) @@ -544,33 +605,15 @@ static int gfs2_commit_write(struct file *file, struct page *page, brelse(dibh); gfs2_trans_end(sdp); +failed: if (al->al_requested) { gfs2_inplace_release(ip); gfs2_quota_unlock(ip); gfs2_alloc_put(ip); } - unlock_page(page); - gfs2_glock_dq_m(1, &ip->i_gh); - lock_page(page); + gfs2_glock_dq(&ip->i_gh); gfs2_holder_uninit(&ip->i_gh); - return 0; - -fail: - brelse(dibh); -fail_endtrans: - gfs2_trans_end(sdp); - if (al->al_requested) { - gfs2_inplace_release(ip); - gfs2_quota_unlock(ip); - gfs2_alloc_put(ip); - } - unlock_page(page); - gfs2_glock_dq_m(1, &ip->i_gh); - lock_page(page); - gfs2_holder_uninit(&ip->i_gh); -fail_nounlock: - ClearPageUptodate(page); - return error; + return ret; } /** @@ -799,8 +842,8 @@ const struct address_space_operations gfs2_file_aops = { .readpage = gfs2_readpage, .readpages = gfs2_readpages, .sync_page = block_sync_page, - .prepare_write = gfs2_prepare_write, - .commit_write = gfs2_commit_write, + .write_begin = gfs2_write_begin, + .write_end = gfs2_write_end, .set_page_dirty = gfs2_set_page_dirty, .bmap = gfs2_bmap, .invalidatepage = gfs2_invalidatepage, |
