[PATCH] JFFS2 appears to "freeze" during erase, version 2
Joakim Tjernlund
joakim.tjernlund at transmode.se
Tue Jun 5 03:51:15 EDT 2007
Here is an updated version that contains all everything in one patch. I hope
this one can be applied as is.
Jocke
>From 87cd93db5895e1506a6abb0dbc891587e96d8547 Mon Sep 17 00:00:00 2001
From: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
Date: Tue, 5 Jun 2007 09:38:53 +0200
Subject: [PATCH] JFFS2 appears to "freeze" during erase
Radoslaw Bisewski <radbis at googlemail.com> writes:
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.
Additional bug fixes by me.
Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
---
fs/jffs2/erase.c | 22 ++++++++++++++++++++--
1 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/fs/jffs2/erase.c b/fs/jffs2/erase.c
index ad01210..0506a3c 100644
--- a/fs/jffs2/erase.c
+++ b/fs/jffs2/erase.c
@@ -52,12 +52,14 @@ 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;
}
@@ -84,12 +86,14 @@ 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;
}
@@ -116,6 +120,7 @@ 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) {
@@ -136,6 +141,7 @@ 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);
@@ -145,22 +151,24 @@ void jffs2_erase_pending_blocks(struct jffs2_sb_info *c, int count)
/* Be nice */
cond_resched();
+ 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);
}
@@ -174,22 +182,26 @@ 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);
}
@@ -419,6 +431,7 @@ 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;
@@ -431,23 +444,28 @@ 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;
}
--
1.5.1.3
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