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Move compress_{alloc,free}_pages up for use by async I/O

This commit is contained in:
Tom Marshall 2019-10-09 19:49:47 -07:00
parent 7326fe2e14
commit 26152ce1ec
1 changed files with 50 additions and 46 deletions
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96
dm-compress/dm-compress.c
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@ -114,6 +114,56 @@ dm_target_pblk_size(struct dm_target* ti)
return ti->len >> (PBLK_SHIFT - SECTOR_SHIFT);
}
/*************************************
* Page level memory allocator
**************************************/
static void*
compress_alloc_pages(size_t size)
{
unsigned int order = get_order(size);
void* ret;
if (size > (PAGE_SIZE * 128) || order > 7) {
printk(KERN_ERR "%s: size %zu order %u too large\n", __func__, size, order);
return NULL;
}
ret = (void*)__get_free_pages(GFP_KERNEL, order);
if (!ret) {
printk(KERN_ERR "%s: failed to alloc %zu bytes\n", __func__, size);
}
memset(ret, 0, size);
return ret;
}
static void
compress_free_pages(void* ptr, size_t size)
{
unsigned int order = get_order(size);
size_t n;
size_t in_use = 0;
if (!ptr) {
return;
}
for (n = 0; n < (1 << order); ++n) {
struct page* pg = virt_to_page(ptr + n * PAGE_SIZE);
int refcount = page_ref_count(pg);
if (n == 0) {
--refcount;
}
if (refcount) {
++in_use;
}
}
if (in_use) {
printk(KERN_ERR "%s: *** %zu of %zu pages in use ***\n", __func__, in_use, n);
return;
}
free_pages((unsigned long)ptr, order);
}
/**************************************
* Core low-level I/O.
*
@ -631,52 +681,6 @@ lblk_read(struct dm_compress* dc, u64 idx)
* Main functions
**************************************/
static void*
compress_alloc_pages(size_t size)
{
unsigned int order = get_order(size);
void* ret;
if (size > (PAGE_SIZE * 128) || order > 7) {
printk(KERN_ERR "%s: size %zu order %u too large\n", __func__, size, order);
return NULL;
}
ret = (void*)__get_free_pages(GFP_KERNEL, order);
if (!ret) {
printk(KERN_ERR "%s: failed to alloc %zu bytes\n", __func__, size);
}
memset(ret, 0, size);
return ret;
}
static void
compress_free_pages(void* ptr, size_t size)
{
unsigned int order = get_order(size);
size_t n;
size_t in_use = 0;
if (!ptr) {
return;
}
for (n = 0; n < (1 << order); ++n) {
struct page* pg = virt_to_page(ptr + n * PAGE_SIZE);
int refcount = page_ref_count(pg);
if (n == 0) {
--refcount;
}
if (refcount) {
++in_use;
}
}
if (in_use) {
printk(KERN_ERR "%s: *** %zu of %zu pages in use ***\n", __func__, in_use, n);
return;
}
free_pages((unsigned long)ptr, order);
}
static void
compress_free_buffers(struct dm_compress* dc)
{