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Commit 7ef751c5 authored by Andrew Morton's avatar Andrew Morton Committed by Linus Torvalds
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[PATCH] Remove ext2's buffer_head cache 

Remove ext2's open-coded bitmap LRUs.  Core kernel does this for it now.
parent e7ae11b6
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Showing with 107 additions and 249 deletions
fs/ext2/balloc.c
View file @ 7ef751c5
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fs/ext2/ialloc.c
View file @ 7ef751c5
......@@ -30,8 +30,7 @@
*
* The file system contains group descriptors which are located after the
* super block. Each descriptor contains the number of the bitmap block and
* the free blocks count in the block. The descriptors are loaded in memory
* when a file system is mounted (see ext2_read_super).
* the free blocks count in the block.
*/
......@@ -41,8 +40,8 @@
*
* Return buffer_head of bitmap on success or NULL.
*/
static struct buffer_head *read_inode_bitmap (struct super_block * sb,
unsigned long block_group)
static struct buffer_head *
read_inode_bitmap(struct super_block * sb, unsigned long block_group)
{
struct ext2_group_desc *desc;
struct buffer_head *bh = NULL;
......@@ -53,7 +52,7 @@ static struct buffer_head *read_inode_bitmap (struct super_block * sb,
bh = sb_bread(sb, le32_to_cpu(desc->bg_inode_bitmap));
if (!bh)
ext2_error (sb, "read_inode_bitmap",
ext2_error(sb, "read_inode_bitmap",
"Cannot read inode bitmap - "
"block_group = %lu, inode_bitmap = %lu",
block_group, (unsigned long) desc->bg_inode_bitmap);
......@@ -61,75 +60,6 @@ static struct buffer_head *read_inode_bitmap (struct super_block * sb,
return bh;
}
/*
* load_inode_bitmap loads the inode bitmap for a blocks group
*
* It maintains a cache for the last bitmaps loaded. This cache is managed
* with a LRU algorithm.
*
* Notes:
* 1/ There is one cache per mounted file system.
* 2/ If the file system contains less than EXT2_MAX_GROUP_LOADED groups,
* this function reads the bitmap without maintaining a LRU cache.
*
* Return the buffer_head of the bitmap or the ERR_PTR(error)
*/
static struct buffer_head *load_inode_bitmap (struct super_block * sb,
unsigned int block_group)
{
int i, slot = 0;
struct ext2_sb_info *sbi = EXT2_SB(sb);
struct buffer_head *bh = sbi->s_inode_bitmap[0];
if (block_group >= sbi->s_groups_count)
ext2_panic (sb, "load_inode_bitmap",
"block_group >= groups_count - "
"block_group = %d, groups_count = %lu",
block_group, sbi->s_groups_count);
if (sbi->s_loaded_inode_bitmaps > 0 &&
sbi->s_inode_bitmap_number[0] == block_group && bh)
goto found;
if (sbi->s_groups_count <= EXT2_MAX_GROUP_LOADED) {
slot = block_group;
bh = sbi->s_inode_bitmap[slot];
if (!bh)
goto read_it;
if (sbi->s_inode_bitmap_number[slot] == slot)
goto found;
ext2_panic (sb, "load_inode_bitmap",
"block_group != inode_bitmap_number");
}
bh = NULL;
for (i = 0; i < sbi->s_loaded_inode_bitmaps &&
sbi->s_inode_bitmap_number[i] != block_group;
i++)
;
if (i < sbi->s_loaded_inode_bitmaps)
bh = sbi->s_inode_bitmap[i];
else if (sbi->s_loaded_inode_bitmaps < EXT2_MAX_GROUP_LOADED)
sbi->s_loaded_inode_bitmaps++;
else
brelse (sbi->s_inode_bitmap[--i]);
while (i--) {
sbi->s_inode_bitmap_number[i+1] = sbi->s_inode_bitmap_number[i];
sbi->s_inode_bitmap[i+1] = sbi->s_inode_bitmap[i];
}
read_it:
if (!bh)
bh = read_inode_bitmap (sb, block_group);
sbi->s_inode_bitmap_number[slot] = block_group;
sbi->s_inode_bitmap[slot] = bh;
if (!bh)
return ERR_PTR(-EIO);
found:
return bh;
}
/*
* NOTE! When we get the inode, we're the only people
* that have access to it, and as such there are no
......@@ -151,8 +81,8 @@ void ext2_free_inode (struct inode * inode)
struct super_block * sb = inode->i_sb;
int is_directory;
unsigned long ino;
struct buffer_head * bh;
struct buffer_head * bh2;
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *bh2;
unsigned long block_group;
unsigned long bit;
struct ext2_group_desc * desc;
......@@ -186,12 +116,13 @@ void ext2_free_inode (struct inode * inode)
}
block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
bit = (ino - 1) % EXT2_INODES_PER_GROUP(sb);
bh = load_inode_bitmap (sb, block_group);
if (IS_ERR(bh))
brelse(bitmap_bh);
bitmap_bh = read_inode_bitmap(sb, block_group);
if (!bitmap_bh)
goto error_return;
/* Ok, now we can actually update the inode bitmaps.. */
if (!ext2_clear_bit (bit, bh->b_data))
if (!ext2_clear_bit(bit, bitmap_bh->b_data))
ext2_error (sb, "ext2_free_inode",
"bit already cleared for inode %lu", ino);
else {
......@@ -208,13 +139,14 @@ void ext2_free_inode (struct inode * inode)
cpu_to_le32(le32_to_cpu(es->s_free_inodes_count) + 1);
mark_buffer_dirty(EXT2_SB(sb)->s_sbh);
}
mark_buffer_dirty(bh);
mark_buffer_dirty(bitmap_bh);
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
ll_rw_block(WRITE, 1, &bitmap_bh);
wait_on_buffer(bitmap_bh);
}
sb->s_dirt = 1;
error_return:
brelse(bitmap_bh);
unlock_super (sb);
}
......@@ -351,9 +283,9 @@ static int find_group_other(struct super_block *sb, int parent_group)
struct inode * ext2_new_inode(struct inode * dir, int mode)
{
struct super_block * sb;
struct buffer_head * bh;
struct buffer_head * bh2;
struct super_block *sb;
struct buffer_head *bitmap_bh = NULL;
struct buffer_head *bh2;
int group, i;
ino_t ino;
struct inode * inode;
......@@ -361,6 +293,7 @@ struct inode * ext2_new_inode(struct inode * dir, int mode)
struct ext2_super_block * es;
struct ext2_inode_info *ei;
int err;
struct inode *ret;
sb = dir->i_sb;
inode = new_inode(sb);
......@@ -381,20 +314,21 @@ struct inode * ext2_new_inode(struct inode * dir, int mode)
goto fail;
err = -EIO;
bh = load_inode_bitmap (sb, group);
if (IS_ERR(bh))
brelse(bitmap_bh);
bitmap_bh = read_inode_bitmap(sb, group);
if (!bitmap_bh)
goto fail2;
i = ext2_find_first_zero_bit ((unsigned long *) bh->b_data,
i = ext2_find_first_zero_bit((unsigned long *)bitmap_bh->b_data,
EXT2_INODES_PER_GROUP(sb));
if (i >= EXT2_INODES_PER_GROUP(sb))
goto bad_count;
ext2_set_bit (i, bh->b_data);
ext2_set_bit(i, bitmap_bh->b_data);
mark_buffer_dirty(bh);
mark_buffer_dirty(bitmap_bh);
if (sb->s_flags & MS_SYNCHRONOUS) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
ll_rw_block(WRITE, 1, &bitmap_bh);
wait_on_buffer(bitmap_bh);
}
ino = group * EXT2_INODES_PER_GROUP(sb) + i + 1;
......@@ -452,17 +386,19 @@ struct inode * ext2_new_inode(struct inode * dir, int mode)
insert_inode_hash(inode);
mark_inode_dirty(inode);
unlock_super (sb);
unlock_super(sb);
ret = inode;
if(DQUOT_ALLOC_INODE(inode)) {
DQUOT_DROP(inode);
inode->i_flags |= S_NOQUOTA;
inode->i_nlink = 0;
iput(inode);
return ERR_PTR(-EDQUOT);
ret = ERR_PTR(-EDQUOT);
} else {
ext2_debug("allocating inode %lu\n", inode->i_ino);
ext2_preread_inode(inode);
}
ext2_debug ("allocating inode %lu\n", inode->i_ino);
ext2_preread_inode(inode);
return inode;
goto out;
fail2:
desc = ext2_get_group_desc (sb, group, &bh2);
......@@ -476,7 +412,8 @@ struct inode * ext2_new_inode(struct inode * dir, int mode)
unlock_super(sb);
make_bad_inode(inode);
iput(inode);
return ERR_PTR(err);
ret = ERR_PTR(err);
goto out;
bad_count:
ext2_error (sb, "ext2_new_inode",
......@@ -491,6 +428,9 @@ struct inode * ext2_new_inode(struct inode * dir, int mode)
desc->bg_free_inodes_count = 0;
mark_buffer_dirty(bh2);
goto repeat;
out:
brelse(bitmap_bh);
return ret;
}
unsigned long ext2_count_free_inodes (struct super_block * sb)
......@@ -498,30 +438,33 @@ unsigned long ext2_count_free_inodes (struct super_block * sb)
#ifdef EXT2FS_DEBUG
struct ext2_super_block * es;
unsigned long desc_count = 0, bitmap_count = 0;
struct buffer_head *bitmap_bh = NULL;
int i;
lock_super (sb);
es = EXT2_SB(sb)->s_es;
for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
struct ext2_group_desc *desc = ext2_get_group_desc (sb, i, NULL);
struct buffer_head *bh;
struct ext2_group_desc *desc;
unsigned x;
desc = ext2_get_group_desc (sb, i, NULL);
if (!desc)
continue;
desc_count += le16_to_cpu(desc->bg_free_inodes_count);
bh = load_inode_bitmap (sb, i);
if (IS_ERR(bh))
brelse(bitmap_bh);
bitmap_bh = read_inode_bitmap(sb, i);
if (!bitmap_bh)
continue;
x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8);
x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
printk ("group %d: stored = %d, counted = %lu\n",
i, le16_to_cpu(desc->bg_free_inodes_count), x);
bitmap_count += x;
}
brelse(bitmap_bh);
printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n",
le32_to_cpu(es->s_free_inodes_count), desc_count, bitmap_count);
unlock_super (sb);
unlock_super(sb);
return desc_count;
#else
return le32_to_cpu(EXT2_SB(sb)->s_es->s_free_inodes_count);
......@@ -534,21 +477,23 @@ void ext2_check_inodes_bitmap (struct super_block * sb)
{
struct ext2_super_block * es = EXT2_SB(sb)->s_es;
unsigned long desc_count = 0, bitmap_count = 0;
struct buffer_head *bitmap_bh = NULL;
int i;
for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) {
struct ext2_group_desc *desc = ext2_get_group_desc(sb, i, NULL);
struct buffer_head *bh;
struct ext2_group_desc *desc;
unsigned x;
desc = ext2_get_group_desc(sb, i, NULL);
if (!desc)
continue;
desc_count += le16_to_cpu(desc->bg_free_inodes_count);
bh = load_inode_bitmap (sb, i);
if (IS_ERR(bh))
brelse(bitmap_bh);
bitmap_bh = read_inode_bitmap(sb, i);
if (!bitmap_bh)
continue;
x = ext2_count_free (bh, EXT2_INODES_PER_GROUP(sb) / 8);
x = ext2_count_free(bitmap_bh, EXT2_INODES_PER_GROUP(sb) / 8);
if (le16_to_cpu(desc->bg_free_inodes_count) != x)
ext2_error (sb, "ext2_check_inodes_bitmap",
"Wrong free inodes count in group %d, "
......@@ -556,8 +501,9 @@ void ext2_check_inodes_bitmap (struct super_block * sb)
le16_to_cpu(desc->bg_free_inodes_count), x);
bitmap_count += x;
}
brelse(bitmap_bh);
if (le32_to_cpu(es->s_free_inodes_count) != bitmap_count)
ext2_error (sb, "ext2_check_inodes_bitmap",
ext2_error(sb, "ext2_check_inodes_bitmap",
"Wrong free inodes count in super block, "
"stored = %lu, counted = %lu",
(unsigned long)le32_to_cpu(es->s_free_inodes_count),
......
fs/ext2/super.c
View file @ 7ef751c5
......@@ -142,12 +142,6 @@ static void ext2_put_super (struct super_block * sb)
if (sbi->s_group_desc[i])
brelse (sbi->s_group_desc[i]);
kfree(sbi->s_group_desc);
for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
if (sbi->s_inode_bitmap[i])
brelse (sbi->s_inode_bitmap[i]);
for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++)
if (sbi->s_block_bitmap[i])
brelse (sbi->s_block_bitmap[i]);
brelse (sbi->s_sbh);
sb->u.generic_sbp = NULL;
kfree(sbi);
......@@ -686,14 +680,6 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
db_count = i;
goto failed_mount2;
}
for (i = 0; i < EXT2_MAX_GROUP_LOADED; i++) {
sbi->s_inode_bitmap_number[i] = 0;
sbi->s_inode_bitmap[i] = NULL;
sbi->s_block_bitmap_number[i] = 0;
sbi->s_block_bitmap[i] = NULL;
}
sbi->s_loaded_inode_bitmaps = 0;
sbi->s_loaded_block_bitmaps = 0;
sbi->s_gdb_count = db_count;
get_random_bytes(&sbi->s_next_generation, sizeof(u32));
/*
......
include/linux/ext2_fs_sb.h
View file @ 7ef751c5
......@@ -16,14 +16,6 @@
#ifndef _LINUX_EXT2_FS_SB
#define _LINUX_EXT2_FS_SB
/*
* The following is not needed anymore since the descriptors buffer
* heads are now dynamically allocated
*/
/* #define EXT2_MAX_GROUP_DESC 8 */
#define EXT2_MAX_GROUP_LOADED 8
/*
* second extended-fs super-block data in memory
*/
......@@ -41,12 +33,6 @@ struct ext2_sb_info {
struct buffer_head * s_sbh; /* Buffer containing the super block */
struct ext2_super_block * s_es; /* Pointer to the super block in the buffer */
struct buffer_head ** s_group_desc;
unsigned short s_loaded_inode_bitmaps;
unsigned short s_loaded_block_bitmaps;
unsigned long s_inode_bitmap_number[EXT2_MAX_GROUP_LOADED];
struct buffer_head * s_inode_bitmap[EXT2_MAX_GROUP_LOADED];
unsigned long s_block_bitmap_number[EXT2_MAX_GROUP_LOADED];
struct buffer_head * s_block_bitmap[EXT2_MAX_GROUP_LOADED];
unsigned long s_mount_opt;
uid_t s_resuid;
gid_t s_resgid;
......
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