From: Mingming Cao <cmm@us.ibm.com>
Since now the ei->truncate_sem is guarding the concurrent allocation and
the deallocation, there is no need to use the the rsv_seqlock lock in the
ext3_reserve_window_node, which was there to protect using/allocating
reservation window race between two threads allocating blocks at the same
time.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---
25-akpm/fs/ext3/balloc.c | 30 +++++++++++-------------------
25-akpm/fs/ext3/ioctl.c | 5 ++---
25-akpm/include/linux/ext3_fs_i.h | 5 ++---
3 files changed, 15 insertions(+), 25 deletions(-)
diff -puN fs/ext3/balloc.c~ext3-reservation-info-cleanup-remove-rsv_seqlock fs/ext3/balloc.c
--- 25/fs/ext3/balloc.c~ext3-reservation-info-cleanup-remove-rsv_seqlock 2005-03-23 01:33:50.000000000 -0800
+++ 25-akpm/fs/ext3/balloc.c 2005-03-23 01:33:50.000000000 -0800
@@ -250,7 +250,7 @@ static void rsv_window_remove(struct sup
{
rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
- atomic_set(&rsv->rsv_alloc_hit, 0);
+ rsv->rsv_alloc_hit = 0;
rb_erase(&rsv->rsv_node, &EXT3_SB(sb)->s_rsv_window_root);
}
@@ -268,9 +268,8 @@ void ext3_alloc_init_reservation(struct
if (rsv) {
rsv->rsv_start = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
rsv->rsv_end = EXT3_RESERVE_WINDOW_NOT_ALLOCATED;
- atomic_set(&rsv->rsv_goal_size, EXT3_DEFAULT_RESERVE_BLOCKS);
- atomic_set(&rsv->rsv_alloc_hit, 0);
- seqlock_init(&rsv->rsv_seqlock);
+ rsv->rsv_goal_size = EXT3_DEFAULT_RESERVE_BLOCKS;
+ rsv->rsv_alloc_hit = 0;
}
ei->i_rsv_window = rsv;
}
@@ -856,7 +855,7 @@ static int alloc_new_reservation(struct
else
start_block = goal + group_first_block;
- size = atomic_read(&my_rsv->rsv_goal_size);
+ size = my_rsv->rsv_goal_size;
if (!rsv_is_empty(&my_rsv->rsv_window)) {
/*
* if the old reservation is cross group boundary
@@ -877,7 +876,7 @@ static int alloc_new_reservation(struct
(start_block >= my_rsv->rsv_start))
return -1;
- if ((atomic_read(&my_rsv->rsv_alloc_hit) >
+ if ((my_rsv->rsv_alloc_hit >
(my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) {
/*
* if we previously allocation hit ration is greater than half
@@ -887,7 +886,7 @@ static int alloc_new_reservation(struct
size = size * 2;
if (size > EXT3_MAX_RESERVE_BLOCKS)
size = EXT3_MAX_RESERVE_BLOCKS;
- atomic_set(&my_rsv->rsv_goal_size, size);
+ my_rsv->rsv_goal_size= size;
}
}
/*
@@ -962,7 +961,7 @@ found_rsv_window:
}
my_rsv->rsv_start = reservable_space_start;
my_rsv->rsv_end = my_rsv->rsv_start + size - 1;
- atomic_set(&my_rsv->rsv_alloc_hit, 0);
+ my_rsv->rsv_alloc_hit = 0;
if (my_rsv != prev_rsv) {
ext3_rsv_window_add(sb, my_rsv);
}
@@ -1061,23 +1060,17 @@ ext3_try_to_allocate_with_rsv(struct sup
*/
while (1) {
struct ext3_reserve_window rsv_copy;
- unsigned int seq;
- do {
- seq = read_seqbegin(&my_rsv->rsv_seqlock);
- rsv_copy._rsv_start = my_rsv->rsv_start;
- rsv_copy._rsv_end = my_rsv->rsv_end;
- } while (read_seqretry(&my_rsv->rsv_seqlock, seq));
+ rsv_copy._rsv_start = my_rsv->rsv_start;
+ rsv_copy._rsv_end = my_rsv->rsv_end;
if (rsv_is_empty(&rsv_copy) || (ret < 0) ||
!goal_in_my_reservation(&rsv_copy, goal, group, sb)) {
spin_lock(rsv_lock);
- write_seqlock(&my_rsv->rsv_seqlock);
ret = alloc_new_reservation(my_rsv, goal, sb,
group, bitmap_bh);
rsv_copy._rsv_start = my_rsv->rsv_start;
rsv_copy._rsv_end = my_rsv->rsv_end;
- write_sequnlock(&my_rsv->rsv_seqlock);
spin_unlock(rsv_lock);
if (ret < 0)
break; /* failed */
@@ -1091,8 +1084,7 @@ ext3_try_to_allocate_with_rsv(struct sup
ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal,
&rsv_copy);
if (ret >= 0) {
- if (!read_seqretry(&my_rsv->rsv_seqlock, seq))
- atomic_inc(&my_rsv->rsv_alloc_hit);
+ my_rsv->rsv_alloc_hit++;
break; /* succeed */
}
}
@@ -1202,7 +1194,7 @@ int ext3_new_block(handle_t *handle, str
* command EXT3_IOC_SETRSVSZ to set the window size to 0 to turn off
* reservation on that particular file)
*/
- if (rsv && ((windowsz = atomic_read(&rsv->rsv_goal_size)) > 0))
+ if (rsv && ((windowsz = rsv->rsv_goal_size) > 0))
my_rsv = rsv;
if (!ext3_has_free_blocks(sbi)) {
diff -puN fs/ext3/ioctl.c~ext3-reservation-info-cleanup-remove-rsv_seqlock fs/ext3/ioctl.c
--- 25/fs/ext3/ioctl.c~ext3-reservation-info-cleanup-remove-rsv_seqlock 2005-03-23 01:33:50.000000000 -0800
+++ 25-akpm/fs/ext3/ioctl.c 2005-03-23 01:33:50.000000000 -0800
@@ -156,7 +156,7 @@ flags_err:
if (test_opt(inode->i_sb, RESERVATION)
&& S_ISREG(inode->i_mode)
&& ei->i_rsv_window) {
- rsv_window_size = atomic_read(&ei->i_rsv_window->rsv_goal_size);
+ rsv_window_size = ei->i_rsv_window->rsv_goal_size;
return put_user(rsv_window_size, (int __user *)arg);
}
return -ENOTTY;
@@ -186,8 +186,7 @@ flags_err:
ext3_alloc_init_reservation(inode);
if (ei->i_rsv_window)
- atomic_set(&ei->i_rsv_window->rsv_goal_size,
- rsv_window_size);
+ ei->i_rsv_window->rsv_goal_size = rsv_window_size;
up(&ei->truncate_sem);
return 0;
}
diff -puN include/linux/ext3_fs_i.h~ext3-reservation-info-cleanup-remove-rsv_seqlock include/linux/ext3_fs_i.h
--- 25/include/linux/ext3_fs_i.h~ext3-reservation-info-cleanup-remove-rsv_seqlock 2005-03-23 01:33:50.000000000 -0800
+++ 25-akpm/include/linux/ext3_fs_i.h 2005-03-23 01:33:50.000000000 -0800
@@ -27,9 +27,8 @@ struct ext3_reserve_window {
struct ext3_reserve_window_node {
struct rb_node rsv_node;
- atomic_t rsv_goal_size;
- atomic_t rsv_alloc_hit;
- seqlock_t rsv_seqlock;
+ __u32 rsv_goal_size;
+ __u32 rsv_alloc_hit;
struct ext3_reserve_window rsv_window;
};
_