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yaml
---
r: 3900
b: refs/heads/master
c: 21fe347
h: refs/heads/master
v: v3
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Mingming Cao authored and Linus Torvalds committed Jun 29, 2005
1 parent 05a412d commit 49a591c
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Showing 3 changed files with 68 additions and 73 deletions.
2 changes: 1 addition & 1 deletion [refs]
View file
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: fb3cc4320e1fd87143683b540e459a2e20fdc9bb
refs/heads/master: 21fe3471c3aaa5c489c5d3a4d705291eb7511248
135 changes: 63 additions & 72 deletions trunk/fs/ext3/balloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -749,24 +749,24 @@ ext3_try_to_allocate(struct super_block *sb, handle_t *handle, int group,
* to find a free region that is of my size and has not
* been reserved.
*
* on succeed, it returns the reservation window to be appended to.
* failed, return NULL.
*/
static struct ext3_reserve_window_node *find_next_reservable_window(
static int find_next_reservable_window(
struct ext3_reserve_window_node *search_head,
unsigned long size, int *start_block,
struct ext3_reserve_window_node *my_rsv,
struct super_block * sb, int start_block,
int last_block)
{
struct rb_node *next;
struct ext3_reserve_window_node *rsv, *prev;
int cur;
int size = my_rsv->rsv_goal_size;

/* TODO: make the start of the reservation window byte-aligned */
/* cur = *start_block & ~7;*/
cur = *start_block;
cur = start_block;
rsv = search_head;
if (!rsv)
return NULL;
return -1;

while (1) {
if (cur <= rsv->rsv_end)
Expand All @@ -782,11 +782,11 @@ static struct ext3_reserve_window_node *find_next_reservable_window(
* space with expected-size (or more)...
*/
if (cur > last_block)
return NULL; /* fail */
return -1; /* fail */

prev = rsv;
next = rb_next(&rsv->rsv_node);
rsv = list_entry(next, struct ext3_reserve_window_node, rsv_node);
rsv = list_entry(next,struct ext3_reserve_window_node,rsv_node);

/*
* Reached the last reservation, we can just append to the
Expand All @@ -813,8 +813,25 @@ static struct ext3_reserve_window_node *find_next_reservable_window(
* return the reservation window that we could append to.
* succeed.
*/
*start_block = cur;
return prev;

if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window)))
rsv_window_remove(sb, my_rsv);

/*
* Let's book the whole avaliable window for now. We will check the
* disk bitmap later and then, if there are free blocks then we adjust
* the window size if it's larger than requested.
* Otherwise, we will remove this node from the tree next time
* call find_next_reservable_window.
*/
my_rsv->rsv_start = cur;
my_rsv->rsv_end = cur + size - 1;
my_rsv->rsv_alloc_hit = 0;

if (prev != my_rsv)
ext3_rsv_window_add(sb, my_rsv);

return 0;
}

/**
Expand Down Expand Up @@ -852,6 +869,7 @@ static struct ext3_reserve_window_node *find_next_reservable_window(
* @sb: the super block
* @group: the group we are trying to allocate in
* @bitmap_bh: the block group block bitmap
*
*/
static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
int goal, struct super_block *sb,
Expand All @@ -860,10 +878,10 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
struct ext3_reserve_window_node *search_head;
int group_first_block, group_end_block, start_block;
int first_free_block;
int reservable_space_start;
struct ext3_reserve_window_node *prev_rsv;
struct rb_root *fs_rsv_root = &EXT3_SB(sb)->s_rsv_window_root;
unsigned long size;
int ret;
spinlock_t *rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;

group_first_block = le32_to_cpu(EXT3_SB(sb)->s_es->s_first_data_block) +
group * EXT3_BLOCKS_PER_GROUP(sb);
Expand All @@ -875,6 +893,7 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
start_block = goal + group_first_block;

size = my_rsv->rsv_goal_size;

if (!rsv_is_empty(&my_rsv->rsv_window)) {
/*
* if the old reservation is cross group boundary
Expand Down Expand Up @@ -908,6 +927,8 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
my_rsv->rsv_goal_size= size;
}
}

spin_lock(rsv_lock);
/*
* shift the search start to the window near the goal block
*/
Expand All @@ -921,11 +942,16 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
* need to check the bitmap after we found a reservable window.
*/
retry:
prev_rsv = find_next_reservable_window(search_head, size,
&start_block, group_end_block);
if (prev_rsv == NULL)
goto failed;
reservable_space_start = start_block;
ret = find_next_reservable_window(search_head, my_rsv, sb,
start_block, group_end_block);

if (ret == -1) {
if (!rsv_is_empty(&my_rsv->rsv_window))
rsv_window_remove(sb, my_rsv);
spin_unlock(rsv_lock);
return -1;
}

/*
* On success, find_next_reservable_window() returns the
* reservation window where there is a reservable space after it.
Expand All @@ -937,63 +963,39 @@ static int alloc_new_reservation(struct ext3_reserve_window_node *my_rsv,
* block. Search start from the start block of the reservable space
* we just found.
*/
spin_unlock(rsv_lock);
first_free_block = bitmap_search_next_usable_block(
reservable_space_start - group_first_block,
my_rsv->rsv_start - group_first_block,
bitmap_bh, group_end_block - group_first_block + 1);

if (first_free_block < 0) {
/*
* no free block left on the bitmap, no point
* to reserve the space. return failed.
*/
goto failed;
spin_lock(rsv_lock);
if (!rsv_is_empty(&my_rsv->rsv_window))
rsv_window_remove(sb, my_rsv);
spin_unlock(rsv_lock);
return -1; /* failed */
}

start_block = first_free_block + group_first_block;
/*
* check if the first free block is within the
* free space we just found
* free space we just reserved
*/
if ((start_block >= reservable_space_start) &&
(start_block < reservable_space_start + size))
goto found_rsv_window;
if (start_block >= my_rsv->rsv_start && start_block < my_rsv->rsv_end)
return 0; /* success */
/*
* if the first free bit we found is out of the reservable space
* this means there is no free block on the reservable space
* we should continue search for next reservable space,
* continue search for next reservable space,
* start from where the free block is,
* we also shift the list head to where we stopped last time
*/
search_head = prev_rsv;
search_head = my_rsv;
spin_lock(rsv_lock);
goto retry;

found_rsv_window:
/*
* great! the reservable space contains some free blocks.
* if the search returns that we should add the new
* window just next to where the old window, we don't
* need to remove the old window first then add it to the
* same place, just update the new start and new end.
*/
if (my_rsv != prev_rsv) {
if (!rsv_is_empty(&my_rsv->rsv_window))
rsv_window_remove(sb, my_rsv);
}
my_rsv->rsv_start = reservable_space_start;
my_rsv->rsv_end = my_rsv->rsv_start + size - 1;
my_rsv->rsv_alloc_hit = 0;
if (my_rsv != prev_rsv) {
ext3_rsv_window_add(sb, my_rsv);
}
return 0; /* succeed */
failed:
/*
* failed to find a new reservation window in the current
* group, remove the current(stale) reservation window
* if there is any
*/
if (!rsv_is_empty(&my_rsv->rsv_window))
rsv_window_remove(sb, my_rsv);
return -1; /* failed */
}

/*
Expand Down Expand Up @@ -1023,7 +1025,6 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
int goal, struct ext3_reserve_window_node * my_rsv,
int *errp)
{
spinlock_t *rsv_lock;
unsigned long group_first_block;
int ret = 0;
int fatal;
Expand Down Expand Up @@ -1052,7 +1053,6 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal, NULL);
goto out;
}
rsv_lock = &EXT3_SB(sb)->s_rsv_window_lock;
/*
* goal is a group relative block number (if there is a goal)
* 0 < goal < EXT3_BLOCKS_PER_GROUP(sb)
Expand All @@ -1078,30 +1078,21 @@ ext3_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
* then we could go to allocate from the reservation window directly.
*/
while (1) {
struct ext3_reserve_window rsv_copy;

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);
if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) ||
!goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb)) {
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;
spin_unlock(rsv_lock);
if (ret < 0)
break; /* failed */

if (!goal_in_my_reservation(&rsv_copy, goal, group, sb))
if (!goal_in_my_reservation(&my_rsv->rsv_window, goal, group, sb))
goal = -1;
}
if ((rsv_copy._rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
|| (rsv_copy._rsv_end < group_first_block))
if ((my_rsv->rsv_start >= group_first_block + EXT3_BLOCKS_PER_GROUP(sb))
|| (my_rsv->rsv_end < group_first_block))
BUG();
ret = ext3_try_to_allocate(sb, handle, group, bitmap_bh, goal,
&rsv_copy);
&my_rsv->rsv_window);
if (ret >= 0) {
my_rsv->rsv_alloc_hit++;
break; /* succeed */
Expand Down
4 changes: 4 additions & 0 deletions trunk/fs/ext3/file.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,7 +36,11 @@ static int ext3_release_file (struct inode * inode, struct file * filp)
/* if we are the last writer on the inode, drop the block reservation */
if ((filp->f_mode & FMODE_WRITE) &&
(atomic_read(&inode->i_writecount) == 1))
{
down(&EXT3_I(inode)->truncate_sem);
ext3_discard_reservation(inode);
up(&EXT3_I(inode)->truncate_sem);
}
if (is_dx(inode) && filp->private_data)
ext3_htree_free_dir_info(filp->private_data);

Expand Down

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