[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 <Joakim.Tjernlund@transmode.se>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
This commit is contained in:
Joakim Tjernlund 2007-06-27 01:24:09 +02:00 committed by David Woodhouse
parent f79c44980a
commit d364fb18cd

View file

@ -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;
}