Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423295AbWJZL7p (ORCPT ); Thu, 26 Oct 2006 07:59:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423305AbWJZL7p (ORCPT ); Thu, 26 Oct 2006 07:59:45 -0400 Received: from to-mmp-01.tel-ott.com ([142.46.202.39]:18581 "EHLO to-mmp-01.tel-ott.com") by vger.kernel.org with ESMTP id S1423295AbWJZL7o (ORCPT ); Thu, 26 Oct 2006 07:59:44 -0400 Date: Thu, 26 Oct 2006 07:59:42 -0400 From: Holden Karau Subject: [PATCH 1/1] fat: improve sync performance by grouping writes in fat_mirror_bhs [really unmangled] To: Josef Sipek Cc: hirofumi@mail.parknet.co.jp, linux-kernel@vger.kernel.org, holdenk@xandros.com, "akpm@osdl.org" , linux-fsdevel@vger.kernel.org, holden@pigscanfly.ca, holden.karau@gmail.com Message-id: <4540A32E.5050602@pigscanfly.ca> MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7BIT User-Agent: Thunderbird 1.5.0.7 (X11/20060918) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5791 Lines: 184 From: Holden Karau http://www.holdenkarau.com This is an attempt at improving fat_mirror_bhs in sync mode [namely it writes all of the data for a backup block, and then blocks untill finished]. The old behaviour would write & block in smaller chunks, so this should be slightly faster. It also removes the fixme requesting that it be fixed to behave this way :-) Signed-off-by: Holden Karau http://www.holdenkarau.com --- Sorry about the mangled patch, this time it really shouldn't be mangled :-) Important note; I do not normally play with filesystems. This MAY eat your file system, it has not eaten mine but that does not mean much at all [although I don't think it will]. I'd greatly appreciate comments & suggestions. In case the patch gets mangled [again] I've put it up at http://www.holdenkarau.com/~holden/projects/fat/001_improve_fat_sync_performance.patch And now for the actual patch: --- a/fs/fat/fatent.c 2006-09-19 23:42:06.000000000 -0400 +++ b/fs/fat/fatent.c 2006-10-25 19:14:14.000000000 -0400 @@ -1,5 +1,6 @@ /* * Copyright (C) 2004, OGAWA Hirofumi + * Copyright (C) 2006, Holden Karau [Xandros] * Released under GPL v2. */ @@ -343,34 +344,46 @@ int fat_ent_read(struct inode *inode, st return ops->ent_get(fatent); } -/* FIXME: We can write the blocks as more big chunk. */ static int fat_mirror_bhs(struct super_block *sb, struct buffer_head **bhs, - int nr_bhs) + int nr_bhs ) { + return fat_mirror_bhs_optw(sb , bhs , nr_bhs, 0); +} + +static int fat_mirror_bhs_optw(struct super_block *sb, struct buffer_head **bhs, + int nr_bhs , int wait) { struct msdos_sb_info *sbi = MSDOS_SB(sb); - struct buffer_head *c_bh; + struct buffer_head *c_bh[nr_bhs]; int err, n, copy; + /* Always wait if mounted -o sync */ + if (sb->s_flags & MS_SYNCHRONOUS ) { + wait = 1; + } + err = 0; + err = fat_sync_bhs_optw( bhs , nr_bhs , wait); + if (err) + goto error; for (copy = 1; copy < sbi->fats; copy++) { sector_t backup_fat = sbi->fat_length * copy; - for (n = 0; n < nr_bhs; n++) { - c_bh = sb_getblk(sb, backup_fat + bhs[n]->b_blocknr); - if (!c_bh) { + c_bh[n] = sb_getblk(sb, backup_fat + bhs[n]->b_blocknr); + if (!c_bh[n]) { err = -ENOMEM; goto error; } - memcpy(c_bh->b_data, bhs[n]->b_data, sb->s_blocksize); - set_buffer_uptodate(c_bh); - mark_buffer_dirty(c_bh); - if (sb->s_flags & MS_SYNCHRONOUS) - err = sync_dirty_buffer(c_bh); - brelse(c_bh); + set_buffer_uptodate(c_bh[n]); + mark_buffer_dirty(c_bh[n]); + memcpy(c_bh[n]->b_data, bhs[n]->b_data, sb->s_blocksize); + } + err = fat_sync_bhs_optw( c_bh , nr_bhs , wait ); + for (n = 0; n < nr_bhs; n++ ) { + brelse(c_bh[n]); + } if (err) goto error; } - } error: return err; } @@ -383,12 +396,7 @@ int fat_ent_write(struct inode *inode, s int err; ops->ent_put(fatent, new); - if (wait) { - err = fat_sync_bhs(fatent->bhs, fatent->nr_bhs); - if (err) - return err; - } - return fat_mirror_bhs(sb, fatent->bhs, fatent->nr_bhs); + return fat_mirror_bhs_optw(sb, fatent->bhs, fatent->nr_bhs , wait); } static inline int fat_ent_next(struct msdos_sb_info *sbi, @@ -505,9 +513,9 @@ out: fatent_brelse(&fatent); if (!err) { if (inode_needs_sync(inode)) - err = fat_sync_bhs(bhs, nr_bhs); - if (!err) - err = fat_mirror_bhs(sb, bhs, nr_bhs); + err = fat_mirror_bhs_optw(sb , bhs, nr_bhs , 1); + else + err = fat_mirror_bhs_optw(sb, bhs, nr_bhs , 0 ); } for (i = 0; i < nr_bhs; i++) brelse(bhs[i]); @@ -549,11 +557,6 @@ int fat_free_clusters(struct inode *inod } if (nr_bhs + fatent.nr_bhs > MAX_BUF_PER_PAGE) { - if (sb->s_flags & MS_SYNCHRONOUS) { - err = fat_sync_bhs(bhs, nr_bhs); - if (err) - goto error; - } err = fat_mirror_bhs(sb, bhs, nr_bhs); if (err) goto error; @@ -564,11 +567,6 @@ int fat_free_clusters(struct inode *inod fat_collect_bhs(bhs, &nr_bhs, &fatent); } while (cluster != FAT_ENT_EOF); - if (sb->s_flags & MS_SYNCHRONOUS) { - err = fat_sync_bhs(bhs, nr_bhs); - if (err) - goto error; - } err = fat_mirror_bhs(sb, bhs, nr_bhs); error: fatent_brelse(&fatent); --- a/fs/fat/misc.c 2006-09-19 23:42:06.000000000 -0400 +++ b/fs/fat/misc.c 2006-10-25 18:54:27.000000000 -0400 @@ -194,11 +194,17 @@ void fat_date_unix2dos(int unix_date, __ EXPORT_SYMBOL_GPL(fat_date_unix2dos); -int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs) + +int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs ) { + return fat_sync_bhs_optw(bhs , nr_bhs , 1); +} + +int fat_sync_bhs_optw(struct buffer_head **bhs, int nr_bhs ,int wait) { int i, err = 0; ll_rw_block(SWRITE, nr_bhs, bhs); + if (wait) { for (i = 0; i < nr_bhs; i++) { wait_on_buffer(bhs[i]); if (buffer_eopnotsupp(bhs[i])) { @@ -207,6 +213,7 @@ int fat_sync_bhs(struct buffer_head **bh } else if (!err && !buffer_uptodate(bhs[i])) err = -EIO; } + } return err; } --- a/include/linux/msdos_fs.h 2006-09-19 23:42:06.000000000 -0400 +++ b/include/linux/msdos_fs.h 2006-10-25 18:53:50.000000000 -0400 @@ -419,6 +419,7 @@ extern int fat_chain_add(struct inode *i extern int date_dos2unix(unsigned short time, unsigned short date); extern void fat_date_unix2dos(int unix_date, __le16 *time, __le16 *date); extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); +extern int fat_sync_bhs_optw(struct buffer_head **bhs, int nr_bhs, int wait); int fat_cache_init(void); void fat_cache_destroy(void); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/