From d364fb18cd991734eb54aa8840e70030b0c9f699 Mon Sep 17 00:00:00 2001 From: Joakim Tjernlund Date: Wed, 27 Jun 2007 01:24:09 +0200 Subject: [PATCH] [JFFS2] Reduce time for which erase_free_sem is held during erase. With current desing erase_free_sem is locked every time the flash block is being erased. For NOR flashes - ~1 second is needed to erase single flash block. In the worst case scenario erase_free_sem may be locked for a couple of seconds when the number of blocks is being erased (e.g. after large file was removed). When erase_free_sem is locked all read/write operations for given JFFS2 partition are locked too - in effect from time to time access to the JFFS2 partition is locked for a number of seconds. This fix makes critical section in flash erasing procedure shorter - now erase_free_sem is locked around erase_completion_lock spinlock only. Originally from Radoslaw Bisewski Signed-off-by: Joakim Tjernlund Signed-off-by: David Woodhouse --- fs/jffs2/erase.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/fs/jffs2/erase.c b/fs/jffs2/erase.c index e9e3c2c..f81148a 100644 --- a/fs/jffs2/erase.c +++ b/fs/jffs2/erase.c @@ -50,12 +50,14 @@ static void jffs2_erase_block(struct jffs2_sb_info *c, instr = kmalloc(sizeof(struct erase_info) + sizeof(struct erase_priv_struct), GFP_KERNEL); if (!instr) { printk(KERN_WARNING "kmalloc for struct erase_info in jffs2_erase_block failed. Refiling block for later\n"); + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); list_move(&jeb->list, &c->erase_pending_list); c->erasing_size -= c->sector_size; c->dirty_size += c->sector_size; jeb->dirty_size = c->sector_size; spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); return; } @@ -82,12 +84,14 @@ static void jffs2_erase_block(struct jffs2_sb_info *c, if (ret == -ENOMEM || ret == -EAGAIN) { /* Erase failed immediately. Refile it on the list */ D1(printk(KERN_DEBUG "Erase at 0x%08x failed: %d. Refiling on erase_pending_list\n", jeb->offset, ret)); + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); list_move(&jeb->list, &c->erase_pending_list); c->erasing_size -= c->sector_size; c->dirty_size += c->sector_size; jeb->dirty_size = c->sector_size; spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); return; } @@ -114,6 +118,7 @@ void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count) jeb = list_entry(c->erase_complete_list.next, struct jffs2_eraseblock, list); list_del(&jeb->list); spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); jffs2_mark_erased_block(c, jeb); if (!--count) { @@ -134,6 +139,7 @@ void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count) jffs2_free_jeb_node_refs(c, jeb); list_add(&jeb->list, &c->erasing_list); spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); jffs2_erase_block(c, jeb); @@ -143,22 +149,24 @@ void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count) /* Be nice */ yield(); + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); } spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); done: D1(printk(KERN_DEBUG "jffs2_erase_pending_blocks completed\n")); - - up(&c->erase_free_sem); } static void jffs2_erase_succeeded(struct jffs2_sb_info *c, struct jffs2_eraseblock *jeb) { D1(printk(KERN_DEBUG "Erase completed successfully at 0x%08x\n", jeb->offset)); + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); list_move_tail(&jeb->list, &c->erase_complete_list); spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); /* Ensure that kupdated calls us again to mark them clean */ jffs2_erase_pending_trigger(c); } @@ -172,22 +180,26 @@ static void jffs2_erase_failed(struct jffs2_sb_info *c, struct jffs2_eraseblock failed too many times. */ if (!jffs2_write_nand_badblock(c, jeb, bad_offset)) { /* We'd like to give this block another try. */ + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); list_move(&jeb->list, &c->erase_pending_list); c->erasing_size -= c->sector_size; c->dirty_size += c->sector_size; jeb->dirty_size = c->sector_size; spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); return; } } + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); c->erasing_size -= c->sector_size; c->bad_size += c->sector_size; list_move(&jeb->list, &c->bad_list); c->nr_erasing_blocks--; spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); wake_up(&c->erase_wait); } @@ -444,6 +456,7 @@ static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseb jffs2_link_node_ref(c, jeb, jeb->offset | REF_NORMAL, c->cleanmarker_size, NULL); } + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); c->erasing_size -= c->sector_size; c->free_size += jeb->free_size; @@ -456,23 +469,28 @@ static void jffs2_mark_erased_block(struct jffs2_sb_info *c, struct jffs2_eraseb c->nr_erasing_blocks--; c->nr_free_blocks++; spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); wake_up(&c->erase_wait); return; filebad: + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); /* Stick it on a list (any list) so erase_failed can take it right off again. Silly, but shouldn't happen often. */ list_add(&jeb->list, &c->erasing_list); spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); jffs2_erase_failed(c, jeb, bad_offset); return; refile: /* Stick it back on the list from whence it came and come back later */ jffs2_erase_pending_trigger(c); + down(&c->erase_free_sem); spin_lock(&c->erase_completion_lock); list_add(&jeb->list, &c->erase_complete_list); spin_unlock(&c->erase_completion_lock); + up(&c->erase_free_sem); return; } -- 1.8.2.3