This is a note to let you know that I've just added the patch titled
erofs: clean up cached I/O strategies
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-clean-up-cached-i-o-strategies.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d0c27c28c096f5e74d0ad9104715d80278e0d413
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Tue Dec 6 14:03:52 2022 +0800
erofs: clean up cached I/O strategies
[ Upstream commit 1282dea37b09087b8aec59f0774572c16b52276a ]
After commit 4c7e42552b3a ("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@xxxxxxxxxxx>
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Yue Hu <huyue2@xxxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20221206060352.152830-1-xiang@xxxxxxxxxx
Stable-dep-of: 967c28b23f6c ("erofs: kill hooked chains to avoid loops on deduplicated compressed images")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index cf4871834ebb2..ccf7c55d477fe 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -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,
@@ -638,20 +646,6 @@ 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)
@@ -688,12 +682,9 @@ 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;
@@ -747,13 +738,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
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:
/*
