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erofs: clean up cached I/O strategies 

After commit 4c7e42552b ("erofs: remove useless cache strategy of
DELAYEDALLOC"), only one cached I/O allocation strategy is supported:

  When cached I/O is preferred, page allocation is applied without
  direct reclaim.  If allocation fails, fall back to inplace I/O.

Let's get rid of z_erofs_cache_alloctype.  No logical changes.

Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Yue Hu <huyue2@coolpad.com>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20221206060352.152830-1-xiang@kernel.org
This commit is contained in:
Gao Xiang 2022-12-06 14:03:52 +08:00
parent 2109901d49
commit 1282dea37b
1 changed files with 31 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
fs/erofs/zdata.c
View File

@ -175,16 +175,6 @@ static void z_erofs_free_pcluster(struct z_erofs_pcluster *pcl)
DBG_BUGON(1);
}
/* how to allocate cached pages for a pcluster */
enum z_erofs_cache_alloctype {
DONTALLOC, /* don't allocate any cached pages */
/*
* try to use cached I/O if page allocation succeeds or fallback
* to in-place I/O instead to avoid any direct reclaim.
*/
TRYALLOC,
};
/*
* tagged pointer with 1-bit tag for all compressed pages
* tag 0 - the page is just found with an extra page reference
@ -292,12 +282,29 @@ struct z_erofs_decompress_frontend {
.inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \
.mode = Z_EROFS_PCLUSTER_FOLLOWED, .backmost = true }
static bool z_erofs_should_alloc_cache(struct z_erofs_decompress_frontend *fe)
{
unsigned int cachestrategy = EROFS_I_SB(fe->inode)->opt.cache_strategy;
if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
return false;
if (fe->backmost)
return true;
if (cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
fe->map.m_la < fe->headoffset)
return true;
return false;
}
static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe,
enum z_erofs_cache_alloctype type,
struct page **pagepool)
{
struct address_space *mc = MNGD_MAPPING(EROFS_I_SB(fe->inode));
struct z_erofs_pcluster *pcl = fe->pcl;
bool shouldalloc = z_erofs_should_alloc_cache(fe);
bool standalone = true;
/*
* optimistic allocation without direct reclaim since inplace I/O
@ -326,18 +333,19 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe,
} else {
/* I/O is needed, no possible to decompress directly */
standalone = false;
switch (type) {
case TRYALLOC:
newpage = erofs_allocpage(pagepool, gfp);
if (!newpage)
continue;
set_page_private(newpage,
Z_EROFS_PREALLOCATED_PAGE);
t = tag_compressed_page_justfound(newpage);
break;
default: /* DONTALLOC */
if (!shouldalloc)
continue;
}
/*
* try to use cached I/O if page allocation
* succeeds or fallback to in-place I/O instead
* to avoid any direct reclaim.
*/
newpage = erofs_allocpage(pagepool, gfp);
if (!newpage)
continue;
set_page_private(newpage, Z_EROFS_PREALLOCATED_PAGE);
t = tag_compressed_page_justfound(newpage);
}
if (!cmpxchg_relaxed(&pcl->compressed_bvecs[i].page, NULL,
@ -637,20 +645,6 @@ static bool z_erofs_collector_end(struct z_erofs_decompress_frontend *fe)
return true;
}
static bool should_alloc_managed_pages(struct z_erofs_decompress_frontend *fe,
unsigned int cachestrategy,
erofs_off_t la)
{
if (cachestrategy <= EROFS_ZIP_CACHE_DISABLED)
return false;
if (fe->backmost)
return true;
return cachestrategy >= EROFS_ZIP_CACHE_READAROUND &&
la < fe->headoffset;
}
static int z_erofs_read_fragment(struct inode *inode, erofs_off_t pos,
struct page *page, unsigned int pageofs,
unsigned int len)
@ -687,12 +681,9 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
struct page *page, struct page **pagepool)
{
struct inode *const inode = fe->inode;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
struct erofs_map_blocks *const map = &fe->map;
const loff_t offset = page_offset(page);
bool tight = true, exclusive;
enum z_erofs_cache_alloctype cache_strategy;
unsigned int cur, end, spiltted;
int err = 0;
@ -746,13 +737,7 @@ repeat:
fe->mode = Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE;
} else {
/* bind cache first when cached decompression is preferred */
if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy,
map->m_la))
cache_strategy = TRYALLOC;
else
cache_strategy = DONTALLOC;
z_erofs_bind_cache(fe, cache_strategy, pagepool);
z_erofs_bind_cache(fe, pagepool);
}
hitted:
/*