[PATCH 1/2] erofs: get rid of `struct z_erofs_collector'

From: Gao Xiang
Date: Tue Mar 01 2022 - 14:51:21 EST


Avoid `struct z_erofs_collector' since there is another context
structure called "struct z_erofs_decompress_frontend".

No logic changes.

Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
---
fs/erofs/zdata.c | 163 ++++++++++++++++++++++-------------------------
1 file changed, 77 insertions(+), 86 deletions(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 423bc1a61da5..2673fc105861 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -192,7 +192,10 @@ enum z_erofs_collectmode {
COLLECT_PRIMARY_FOLLOWED,
};

-struct z_erofs_collector {
+struct z_erofs_decompress_frontend {
+ struct inode *const inode;
+ struct erofs_map_blocks map;
+
struct z_erofs_pagevec_ctor vector;

struct z_erofs_pcluster *pcl, *tailpcl;
@@ -202,13 +205,6 @@ struct z_erofs_collector {
z_erofs_next_pcluster_t owned_head;

enum z_erofs_collectmode mode;
-};
-
-struct z_erofs_decompress_frontend {
- struct inode *const inode;
-
- struct z_erofs_collector clt;
- struct erofs_map_blocks map;

bool readahead;
/* used for applying cache strategy on the fly */
@@ -216,30 +212,26 @@ struct z_erofs_decompress_frontend {
erofs_off_t headoffset;
};

-#define COLLECTOR_INIT() { \
- .owned_head = Z_EROFS_PCLUSTER_TAIL, \
- .mode = COLLECT_PRIMARY_FOLLOWED }
-
#define DECOMPRESS_FRONTEND_INIT(__i) { \
- .inode = __i, .clt = COLLECTOR_INIT(), \
- .backmost = true, }
+ .inode = __i, .owned_head = Z_EROFS_PCLUSTER_TAIL, \
+ .mode = COLLECT_PRIMARY_FOLLOWED }

static struct page *z_pagemap_global[Z_EROFS_VMAP_GLOBAL_PAGES];
static DEFINE_MUTEX(z_pagemap_global_lock);

-static void preload_compressed_pages(struct z_erofs_collector *clt,
+static void preload_compressed_pages(struct z_erofs_decompress_frontend *fe,
struct address_space *mc,
enum z_erofs_cache_alloctype type,
struct page **pagepool)
{
- struct z_erofs_pcluster *pcl = clt->pcl;
+ struct z_erofs_pcluster *pcl = fe->pcl;
bool standalone = true;
gfp_t gfp = (mapping_gfp_mask(mc) & ~__GFP_DIRECT_RECLAIM) |
__GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
struct page **pages;
pgoff_t index;

- if (clt->mode < COLLECT_PRIMARY_FOLLOWED)
+ if (fe->mode < COLLECT_PRIMARY_FOLLOWED)
return;

pages = pcl->compressed_pages;
@@ -288,7 +280,7 @@ static void preload_compressed_pages(struct z_erofs_collector *clt,
* managed cache since it can be moved to the bypass queue instead.
*/
if (standalone)
- clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
+ fe->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
}

/* called by erofs_shrinker to get rid of all compressed_pages */
@@ -350,47 +342,47 @@ int erofs_try_to_free_cached_page(struct page *page)
}

/* page_type must be Z_EROFS_PAGE_TYPE_EXCLUSIVE */
-static bool z_erofs_try_inplace_io(struct z_erofs_collector *clt,
+static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe,
struct page *page)
{
- struct z_erofs_pcluster *const pcl = clt->pcl;
+ struct z_erofs_pcluster *const pcl = fe->pcl;

- while (clt->icpage_ptr > pcl->compressed_pages)
- if (!cmpxchg(--clt->icpage_ptr, NULL, page))
+ while (fe->icpage_ptr > pcl->compressed_pages)
+ if (!cmpxchg(--fe->icpage_ptr, NULL, page))
return true;
return false;
}

/* callers must be with collection lock held */
-static int z_erofs_attach_page(struct z_erofs_collector *clt,
+static int z_erofs_attach_page(struct z_erofs_decompress_frontend *fe,
struct page *page, enum z_erofs_page_type type,
bool pvec_safereuse)
{
int ret;

/* give priority for inplaceio */
- if (clt->mode >= COLLECT_PRIMARY &&
+ if (fe->mode >= COLLECT_PRIMARY &&
type == Z_EROFS_PAGE_TYPE_EXCLUSIVE &&
- z_erofs_try_inplace_io(clt, page))
+ z_erofs_try_inplace_io(fe, page))
return 0;

- ret = z_erofs_pagevec_enqueue(&clt->vector, page, type,
+ ret = z_erofs_pagevec_enqueue(&fe->vector, page, type,
pvec_safereuse);
- clt->cl->vcnt += (unsigned int)ret;
+ fe->cl->vcnt += (unsigned int)ret;
return ret ? 0 : -EAGAIN;
}

-static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt)
+static void z_erofs_try_to_claim_pcluster(struct z_erofs_decompress_frontend *f)
{
- struct z_erofs_pcluster *pcl = clt->pcl;
- z_erofs_next_pcluster_t *owned_head = &clt->owned_head;
+ struct z_erofs_pcluster *pcl = f->pcl;
+ z_erofs_next_pcluster_t *owned_head = &f->owned_head;

/* type 1, nil pcluster (this pcluster doesn't belong to any chain.) */
if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_NIL,
*owned_head) == Z_EROFS_PCLUSTER_NIL) {
*owned_head = &pcl->next;
/* so we can attach this pcluster to our submission chain. */
- clt->mode = COLLECT_PRIMARY_FOLLOWED;
+ f->mode = COLLECT_PRIMARY_FOLLOWED;
return;
}

@@ -401,24 +393,24 @@ static void z_erofs_try_to_claim_pcluster(struct z_erofs_collector *clt)
if (cmpxchg(&pcl->next, Z_EROFS_PCLUSTER_TAIL,
*owned_head) == Z_EROFS_PCLUSTER_TAIL) {
*owned_head = Z_EROFS_PCLUSTER_TAIL;
- clt->mode = COLLECT_PRIMARY_HOOKED;
- clt->tailpcl = NULL;
+ f->mode = COLLECT_PRIMARY_HOOKED;
+ f->tailpcl = NULL;
return;
}
/* type 3, it belongs to a chain, but it isn't the end of the chain */
- clt->mode = COLLECT_PRIMARY;
+ f->mode = COLLECT_PRIMARY;
}

-static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
+static int z_erofs_lookup_collection(struct z_erofs_decompress_frontend *fe,
struct inode *inode,
struct erofs_map_blocks *map)
{
- struct z_erofs_pcluster *pcl = clt->pcl;
+ struct z_erofs_pcluster *pcl = fe->pcl;
struct z_erofs_collection *cl;
unsigned int length;

/* to avoid unexpected loop formed by corrupted images */
- if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
+ if (fe->owned_head == &pcl->next || pcl == fe->tailpcl) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
@@ -449,15 +441,15 @@ static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
}
mutex_lock(&cl->lock);
/* used to check tail merging loop due to corrupted images */
- if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
- clt->tailpcl = pcl;
+ if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL)
+ fe->tailpcl = pcl;

- z_erofs_try_to_claim_pcluster(clt);
- clt->cl = cl;
+ z_erofs_try_to_claim_pcluster(fe);
+ fe->cl = cl;
return 0;
}

-static int z_erofs_register_collection(struct z_erofs_collector *clt,
+static int z_erofs_register_collection(struct z_erofs_decompress_frontend *fe,
struct inode *inode,
struct erofs_map_blocks *map)
{
@@ -485,8 +477,8 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
Z_EROFS_PCLUSTER_FULL_LENGTH : 0);

/* new pclusters should be claimed as type 1, primary and followed */
- pcl->next = clt->owned_head;
- clt->mode = COLLECT_PRIMARY_FOLLOWED;
+ pcl->next = fe->owned_head;
+ fe->mode = COLLECT_PRIMARY_FOLLOWED;

cl = z_erofs_primarycollection(pcl);
cl->pageofs = map->m_la & ~PAGE_MASK;
@@ -512,18 +504,18 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
}

if (grp != &pcl->obj) {
- clt->pcl = container_of(grp,
+ fe->pcl = container_of(grp,
struct z_erofs_pcluster, obj);
err = -EEXIST;
goto err_out;
}
}
/* used to check tail merging loop due to corrupted images */
- if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
- clt->tailpcl = pcl;
- clt->owned_head = &pcl->next;
- clt->pcl = pcl;
- clt->cl = cl;
+ if (fe->owned_head == Z_EROFS_PCLUSTER_TAIL)
+ fe->tailpcl = pcl;
+ fe->owned_head = &pcl->next;
+ fe->pcl = pcl;
+ fe->cl = cl;
return 0;

err_out:
@@ -532,18 +524,18 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
return err;
}

-static int z_erofs_collector_begin(struct z_erofs_collector *clt,
+static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe,
struct inode *inode,
struct erofs_map_blocks *map)
{
struct erofs_workgroup *grp;
int ret;

- DBG_BUGON(clt->cl);
+ DBG_BUGON(fe->cl);

/* must be Z_EROFS_PCLUSTER_TAIL or pointed to previous collection */
- DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_NIL);
- DBG_BUGON(clt->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);
+ DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_NIL);
+ DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_TAIL_CLOSED);

if (map->m_flags & EROFS_MAP_META) {
if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) {
@@ -555,28 +547,28 @@ static int z_erofs_collector_begin(struct z_erofs_collector *clt,

grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
if (grp) {
- clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
+ fe->pcl = container_of(grp, struct z_erofs_pcluster, obj);
} else {
tailpacking:
- ret = z_erofs_register_collection(clt, inode, map);
+ ret = z_erofs_register_collection(fe, inode, map);
if (!ret)
goto out;
if (ret != -EEXIST)
return ret;
}

- ret = z_erofs_lookup_collection(clt, inode, map);
+ ret = z_erofs_lookup_collection(fe, inode, map);
if (ret) {
- erofs_workgroup_put(&clt->pcl->obj);
+ erofs_workgroup_put(&fe->pcl->obj);
return ret;
}

out:
- z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
- clt->cl->pagevec, clt->cl->vcnt);
+ z_erofs_pagevec_ctor_init(&fe->vector, Z_EROFS_NR_INLINE_PAGEVECS,
+ fe->cl->pagevec, fe->cl->vcnt);
/* since file-backed online pages are traversed in reverse order */
- clt->icpage_ptr = clt->pcl->compressed_pages +
- z_erofs_pclusterpages(clt->pcl);
+ fe->icpage_ptr = fe->pcl->compressed_pages +
+ z_erofs_pclusterpages(fe->pcl);
return 0;
}

@@ -610,24 +602,24 @@ static void z_erofs_collection_put(struct z_erofs_collection *cl)
erofs_workgroup_put(&pcl->obj);
}

-static bool z_erofs_collector_end(struct z_erofs_collector *clt)
+static bool z_erofs_collector_end(struct z_erofs_decompress_frontend *fe)
{
- struct z_erofs_collection *cl = clt->cl;
+ struct z_erofs_collection *cl = fe->cl;

if (!cl)
return false;

- z_erofs_pagevec_ctor_exit(&clt->vector, false);
+ z_erofs_pagevec_ctor_exit(&fe->vector, false);
mutex_unlock(&cl->lock);

/*
* if all pending pages are added, don't hold its reference
* any longer if the pcluster isn't hosted by ourselves.
*/
- if (clt->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
+ if (fe->mode < COLLECT_PRIMARY_FOLLOWED_NOINPLACE)
z_erofs_collection_put(cl);

- clt->cl = NULL;
+ fe->cl = NULL;
return true;
}

@@ -651,7 +643,6 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
struct inode *const inode = fe->inode;
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
struct erofs_map_blocks *const map = &fe->map;
- struct z_erofs_collector *const clt = &fe->clt;
const loff_t offset = page_offset(page);
bool tight = true;

@@ -672,7 +663,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
if (offset + cur >= map->m_la &&
offset + cur < map->m_la + map->m_llen) {
/* didn't get a valid collection previously (very rare) */
- if (!clt->cl)
+ if (!fe->cl)
goto restart_now;
goto hitted;
}
@@ -680,7 +671,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
/* go ahead the next map_blocks */
erofs_dbg("%s: [out-of-range] pos %llu", __func__, offset + cur);

- if (z_erofs_collector_end(clt))
+ if (z_erofs_collector_end(fe))
fe->backmost = false;

map->m_la = offset + cur;
@@ -693,11 +684,11 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
if (!(map->m_flags & EROFS_MAP_MAPPED))
goto hitted;

- err = z_erofs_collector_begin(clt, inode, map);
+ err = z_erofs_collector_begin(fe, inode, map);
if (err)
goto err_out;

- if (z_erofs_is_inline_pcluster(clt->pcl)) {
+ if (z_erofs_is_inline_pcluster(fe->pcl)) {
void *mp;

mp = erofs_read_metabuf(&fe->map.buf, inode->i_sb,
@@ -709,8 +700,8 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
goto err_out;
}
get_page(fe->map.buf.page);
- WRITE_ONCE(clt->pcl->compressed_pages[0], fe->map.buf.page);
- clt->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
+ WRITE_ONCE(fe->pcl->compressed_pages[0], fe->map.buf.page);
+ fe->mode = COLLECT_PRIMARY_FOLLOWED_NOINPLACE;
} else {
/* preload all compressed pages (can change mode if needed) */
if (should_alloc_managed_pages(fe, sbi->opt.cache_strategy,
@@ -719,7 +710,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
else
cache_strategy = DONTALLOC;

- preload_compressed_pages(clt, MNGD_MAPPING(sbi),
+ preload_compressed_pages(fe, MNGD_MAPPING(sbi),
cache_strategy, pagepool);
}

@@ -730,8 +721,8 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
* those chains are handled asynchronously thus the page cannot be used
* for inplace I/O or pagevec (should be processed in strict order.)
*/
- tight &= (clt->mode >= COLLECT_PRIMARY_HOOKED &&
- clt->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);
+ tight &= (fe->mode >= COLLECT_PRIMARY_HOOKED &&
+ fe->mode != COLLECT_PRIMARY_FOLLOWED_NOINPLACE);

cur = end - min_t(unsigned int, offset + end - map->m_la, end);
if (!(map->m_flags & EROFS_MAP_MAPPED)) {
@@ -746,18 +737,18 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED));

if (cur)
- tight &= (clt->mode >= COLLECT_PRIMARY_FOLLOWED);
+ tight &= (fe->mode >= COLLECT_PRIMARY_FOLLOWED);

retry:
- err = z_erofs_attach_page(clt, page, page_type,
- clt->mode >= COLLECT_PRIMARY_FOLLOWED);
+ err = z_erofs_attach_page(fe, page, page_type,
+ fe->mode >= COLLECT_PRIMARY_FOLLOWED);
/* should allocate an additional short-lived page for pagevec */
if (err == -EAGAIN) {
struct page *const newpage =
alloc_page(GFP_NOFS | __GFP_NOFAIL);

set_page_private(newpage, Z_EROFS_SHORTLIVED_PAGE);
- err = z_erofs_attach_page(clt, newpage,
+ err = z_erofs_attach_page(fe, newpage,
Z_EROFS_PAGE_TYPE_EXCLUSIVE, true);
if (!err)
goto retry;
@@ -773,7 +764,7 @@ static int z_erofs_do_read_page(struct z_erofs_decompress_frontend *fe,
/* bump up the number of spiltted parts of a page */
++spiltted;
/* also update nr_pages */
- clt->cl->nr_pages = max_t(pgoff_t, clt->cl->nr_pages, index + 1);
+ fe->cl->nr_pages = max_t(pgoff_t, fe->cl->nr_pages, index + 1);
next_part:
/* can be used for verification */
map->m_llen = offset + cur - map->m_la;
@@ -1309,7 +1300,7 @@ static void z_erofs_submit_queue(struct super_block *sb,
z_erofs_next_pcluster_t qtail[NR_JOBQUEUES];
struct z_erofs_decompressqueue *q[NR_JOBQUEUES];
void *bi_private;
- z_erofs_next_pcluster_t owned_head = f->clt.owned_head;
+ z_erofs_next_pcluster_t owned_head = f->owned_head;
/* bio is NULL initially, so no need to initialize last_{index,bdev} */
pgoff_t last_index;
struct block_device *last_bdev;
@@ -1417,7 +1408,7 @@ static void z_erofs_runqueue(struct super_block *sb,
{
struct z_erofs_decompressqueue io[NR_JOBQUEUES];

- if (f->clt.owned_head == Z_EROFS_PCLUSTER_TAIL)
+ if (f->owned_head == Z_EROFS_PCLUSTER_TAIL)
return;
z_erofs_submit_queue(sb, f, pagepool, io, &force_fg);

@@ -1517,7 +1508,7 @@ static int z_erofs_readpage(struct file *file, struct page *page)
err = z_erofs_do_read_page(&f, page, &pagepool);
z_erofs_pcluster_readmore(&f, NULL, 0, &pagepool, false);

- (void)z_erofs_collector_end(&f.clt);
+ (void)z_erofs_collector_end(&f);

/* if some compressed cluster ready, need submit them anyway */
z_erofs_runqueue(inode->i_sb, &f, &pagepool,
@@ -1567,7 +1558,7 @@ static void z_erofs_readahead(struct readahead_control *rac)
put_page(page);
}
z_erofs_pcluster_readmore(&f, rac, 0, &pagepool, false);
- (void)z_erofs_collector_end(&f.clt);
+ (void)z_erofs_collector_end(&f);

z_erofs_runqueue(inode->i_sb, &f, &pagepool,
z_erofs_get_sync_decompress_policy(sbi, nr_pages));
--
2.24.4