From 9641b784ff82cf0a48a6c70ef9867f5fd728de67 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 20 May 2006 16:13:34 +0100 Subject: [JFFS2] Optimise reading of eraseblock summary nodes This improves the time to mount 512MiB of NAND flash on my OLPC prototype by about 4%. We used to read the last page of the eraseblock twice -- once to find the offset of the summary node, and again to actually _read_ the summary node. Now we read the last page only once, and read more only if we need to. We also don't allocate a new buffer just for the summary code -- we use the buffer which was already allocated for the scan. Better still, if the 'buffer' for the scan is actually just a pointer directly into NOR flash, we use that too, avoiding the memcpy() which we used to do. Signed-off-by: David Woodhouse --- fs/jffs2/summary.c | 36 ++++++------------------------------ 1 file changed, 6 insertions(+), 30 deletions(-) (limited to 'fs/jffs2/summary.c') diff --git a/fs/jffs2/summary.c b/fs/jffs2/summary.c index 48293c197f13..82a3706c54d8 100644 --- a/fs/jffs2/summary.c +++ b/fs/jffs2/summary.c @@ -318,7 +318,6 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras raw = jffs2_alloc_raw_node_ref(); if (!raw) { JFFS2_NOTICE("allocation of node reference failed\n"); - kfree(summary); return -ENOMEM; } @@ -326,7 +325,6 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras if (!ic) { JFFS2_NOTICE("scan_make_ino_cache failed\n"); jffs2_free_raw_node_ref(raw); - kfree(summary); return -ENOMEM; } @@ -358,10 +356,8 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras jeb->offset + je32_to_cpu(spd->offset)); fd = jffs2_alloc_full_dirent(spd->nsize+1); - if (!fd) { - kfree(summary); + if (!fd) return -ENOMEM; - } memcpy(&fd->name, spd->name, spd->nsize); fd->name[spd->nsize] = 0; @@ -370,7 +366,6 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras if (!raw) { jffs2_free_full_dirent(fd); JFFS2_NOTICE("allocation of node reference failed\n"); - kfree(summary); return -ENOMEM; } @@ -378,7 +373,6 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras if (!ic) { jffs2_free_full_dirent(fd); jffs2_free_raw_node_ref(raw); - kfree(summary); return -ENOMEM; } @@ -411,45 +405,28 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras default : { JFFS2_WARNING("Unsupported node type found in summary! Exiting..."); - kfree(summary); return -EIO; } } } - kfree(summary); return 0; } /* Process the summary node - called from jffs2_scan_eraseblock() */ - int jffs2_sum_scan_sumnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb, - uint32_t ofs, uint32_t *pseudo_random) + struct jffs2_raw_summary *summary, uint32_t sumsize, + uint32_t *pseudo_random) { struct jffs2_unknown_node crcnode; struct jffs2_raw_node_ref *cache_ref; - struct jffs2_raw_summary *summary; - int ret, sumsize; + int ret, ofs; uint32_t crc; - sumsize = c->sector_size - ofs; - ofs += jeb->offset; + ofs = jeb->offset + c->sector_size - sumsize; dbg_summary("summary found for 0x%08x at 0x%08x (0x%x bytes)\n", - jeb->offset, ofs, sumsize); - - summary = kmalloc(sumsize, GFP_KERNEL); - - if (!summary) { - return -ENOMEM; - } - - ret = jffs2_fill_scan_buf(c, (unsigned char *)summary, ofs, sumsize); - - if (ret) { - kfree(summary); - return ret; - } + jeb->offset, ofs, sumsize); /* OK, now check for node validity and CRC */ crcnode.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK); @@ -499,7 +476,6 @@ int jffs2_sum_scan_sumnode(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb if (!marker_ref) { JFFS2_NOTICE("Failed to allocate node ref for clean marker\n"); - kfree(summary); return -ENOMEM; } -- cgit v1.2.3-59-g8ed1b