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btrfs-progs: make free space checker work on non-4k sectorsize filesystems 

The value of sector for space cache was hardcoded to 4k, and used to
calculate bitmap sizes.  In kernel, the BITS_PER_BITMAP is derived from
PAGE_CACHE_SIZE which is not available for userspace, that can also deal
with filesystem of varying sectorsize.

Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
David Sterba 2014-05-28 11:25:24 +02:00
parent 6c9caa4dd6
commit 2c0e02a568
2 changed files with 25 additions and 15 deletions
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39
free-space-cache.c
View File

@ -25,8 +25,12 @@
#include "crc32c.h"
#include "bitops.h"
#define CACHE_SECTORSIZE 4096
#define BITS_PER_BITMAP (CACHE_SECTORSIZE * 8)
/*
* Kernel always uses PAGE_CACHE_SIZE for sectorsize, but we don't have
* anything like that in userspace and have to get the value from the
* filesystem
*/
#define BITS_PER_BITMAP(sectorsize) ((sectorsize) * 8)
#define MAX_CACHE_BYTES_PER_GIG (32 * 1024)
static int link_free_space(struct btrfs_free_space_ctl *ctl,
@ -48,7 +52,7 @@ static int io_ctl_init(struct io_ctl *io_ctl, u64 size, u64 ino,
struct btrfs_root *root)
{
memset(io_ctl, 0, sizeof(struct io_ctl));
io_ctl->num_pages = (size + CACHE_SECTORSIZE - 1) / CACHE_SECTORSIZE;
io_ctl->num_pages = (size + root->sectorsize - 1) / root->sectorsize;
io_ctl->buffer = kzalloc(size, GFP_NOFS);
if (!io_ctl->buffer)
return -ENOMEM;
@ -75,11 +79,11 @@ static void io_ctl_unmap_page(struct io_ctl *io_ctl)
static void io_ctl_map_page(struct io_ctl *io_ctl, int clear)
{
BUG_ON(io_ctl->index >= io_ctl->num_pages);
io_ctl->cur = io_ctl->buffer + (io_ctl->index++ * CACHE_SECTORSIZE);
io_ctl->cur = io_ctl->buffer + (io_ctl->index++ * io_ctl->root->sectorsize);
io_ctl->orig = io_ctl->cur;
io_ctl->size = CACHE_SECTORSIZE;
io_ctl->size = io_ctl->root->sectorsize;
if (clear)
memset(io_ctl->cur, 0, CACHE_SECTORSIZE);
memset(io_ctl->cur, 0, io_ctl->root->sectorsize);
}
static void io_ctl_drop_pages(struct io_ctl *io_ctl)
@ -203,7 +207,7 @@ static int io_ctl_check_crc(struct io_ctl *io_ctl, int index)
val = *tmp;
io_ctl_map_page(io_ctl, 0);
crc = crc32c(crc, io_ctl->orig + offset, CACHE_SECTORSIZE - offset);
crc = crc32c(crc, io_ctl->orig + offset, io_ctl->root->sectorsize - offset);
btrfs_csum_final(crc, (char *)&crc);
if (val != crc) {
printk("btrfs: csum mismatch on free space cache\n");
@ -250,7 +254,7 @@ static int io_ctl_read_bitmap(struct io_ctl *io_ctl,
if (ret)
return ret;
memcpy(entry->bitmap, io_ctl->cur, CACHE_SECTORSIZE);
memcpy(entry->bitmap, io_ctl->cur, io_ctl->root->sectorsize);
io_ctl_unmap_page(io_ctl);
return 0;
@ -375,7 +379,7 @@ static int __load_free_space_cache(struct btrfs_root *root,
} else {
BUG_ON(!num_bitmaps);
num_bitmaps--;
e->bitmap = kzalloc(CACHE_SECTORSIZE, GFP_NOFS);
e->bitmap = kzalloc(ctl->sectorsize, GFP_NOFS);
if (!e->bitmap) {
free(e);
goto free_cache;
@ -462,8 +466,9 @@ static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
{
u64 bitmap_start;
u64 bytes_per_bitmap;
u32 sectorsize = ctl->sectorsize;
bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
bytes_per_bitmap = BITS_PER_BITMAP(sectorsize) * ctl->unit;
bitmap_start = offset - ctl->start;
bitmap_start = bitmap_start / bytes_per_bitmap;
bitmap_start *= bytes_per_bitmap;
@ -532,6 +537,7 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl,
{
struct rb_node *n = ctl->free_space_offset.rb_node;
struct btrfs_free_space *entry, *prev = NULL;
u32 sectorsize = ctl->sectorsize;
/* find entry that is closest to the 'offset' */
while (1) {
@ -616,7 +622,7 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl,
prev->offset + prev->bytes > offset)
return prev;
}
if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
if (entry->offset + BITS_PER_BITMAP(sectorsize) * ctl->unit > offset)
return entry;
} else if (entry->offset + entry->bytes > offset)
return entry;
@ -626,7 +632,7 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl,
while (1) {
if (entry->bitmap) {
if (entry->offset + BITS_PER_BITMAP *
if (entry->offset + BITS_PER_BITMAP(sectorsize) *
ctl->unit > offset)
break;
} else {
@ -673,14 +679,15 @@ static int search_bitmap(struct btrfs_free_space_ctl *ctl,
unsigned long found_bits = 0;
unsigned long bits, i;
unsigned long next_zero;
u32 sectorsize = ctl->sectorsize;
i = offset_to_bit(bitmap_info->offset, ctl->unit,
max_t(u64, *offset, bitmap_info->offset));
bits = bytes_to_bits(*bytes, ctl->unit);
for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP(sectorsize)) {
next_zero = find_next_zero_bit(bitmap_info->bitmap,
BITS_PER_BITMAP, i);
BITS_PER_BITMAP(sectorsize), i);
if ((next_zero - i) >= bits) {
found_bits = next_zero - i;
break;
@ -767,6 +774,7 @@ int btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group,
if (!ctl)
return -ENOMEM;
ctl->sectorsize = sectorsize;
ctl->unit = sectorsize;
ctl->start = block_group->key.objectid;
ctl->private = block_group;
@ -827,6 +835,7 @@ static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
struct btrfs_free_space *e, *prev = NULL;
struct rb_node *n;
int ret;
u32 sectorsize = ctl->sectorsize;
again:
prev = NULL;
@ -836,7 +845,7 @@ again:
u64 offset = e->offset, bytes = ctl->unit;
u64 end;
end = e->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
end = e->offset + (u64)(BITS_PER_BITMAP(sectorsize) * ctl->unit);
unlink_free_space(ctl, e);
while (!(search_bitmap(ctl, e, &offset, &bytes))) {

1
free-space-cache.h
View File

@ -36,6 +36,7 @@ struct btrfs_free_space_ctl {
int unit;
u64 start;
void *private;
u32 sectorsize;
};
int load_free_space_cache(struct btrfs_fs_info *fs_info,