| Message ID | 20240814195915.249871-3-willy@infradead.org |
|---|---|
| State | New |
| Headers | show |
| Series | Finish converting jffs2 to folios | expand |
在 2024/8/15 3:59, Matthew Wilcox (Oracle) 写道: > Call read_cache_folio() instead of read_cache_page() to get the folio > containing the page. No attempt is made here to support large folios > as I assume that will never be interesting for jffs2. Includes a switch > from kmap to kmap_local which looks safe. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > fs/jffs2/gc.c | 25 ++++++++++++------------- > 1 file changed, 12 insertions(+), 13 deletions(-) Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com> > > diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c > index 5c6602f3c189..822949d0eb00 100644 > --- a/fs/jffs2/gc.c > +++ b/fs/jffs2/gc.c > @@ -1171,7 +1171,7 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era > uint32_t alloclen, offset, orig_end, orig_start; > int ret = 0; > unsigned char *comprbuf = NULL, *writebuf; > - struct page *page; > + struct folio *folio; > unsigned char *pg_ptr; > > memset(&ri, 0, sizeof(ri)); > @@ -1317,25 +1317,25 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era > BUG_ON(start > orig_start); > } > > - /* The rules state that we must obtain the page lock *before* f->sem, so > + /* The rules state that we must obtain the folio lock *before* f->sem, so > * drop f->sem temporarily. Since we also hold c->alloc_sem, nothing's > * actually going to *change* so we're safe; we only allow reading. > * > * It is important to note that jffs2_write_begin() will ensure that its > - * page is marked Uptodate before allocating space. That means that if we > - * end up here trying to GC the *same* page that jffs2_write_begin() is > - * trying to write out, read_cache_page() will not deadlock. */ > + * folio is marked uptodate before allocating space. That means that if we > + * end up here trying to GC the *same* folio that jffs2_write_begin() is > + * trying to write out, read_cache_folio() will not deadlock. */ > mutex_unlock(&f->sem); > - page = read_cache_page(inode->i_mapping, start >> PAGE_SHIFT, > + folio = read_cache_folio(inode->i_mapping, start >> PAGE_SHIFT, > __jffs2_read_folio, NULL); > - if (IS_ERR(page)) { > - pr_warn("read_cache_page() returned error: %ld\n", > - PTR_ERR(page)); > + if (IS_ERR(folio)) { > + pr_warn("read_cache_folio() returned error: %ld\n", > + PTR_ERR(folio)); > mutex_lock(&f->sem); > - return PTR_ERR(page); > + return PTR_ERR(folio); > } > > - pg_ptr = kmap(page); > + pg_ptr = kmap_local_folio(folio, 0); > mutex_lock(&f->sem); > > offset = start; > @@ -1400,7 +1400,6 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era > } > } > > - kunmap(page); > - put_page(page); > + folio_release_kmap(folio, pg_ptr); > return ret; > } >
diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c index 5c6602f3c189..822949d0eb00 100644 --- a/fs/jffs2/gc.c +++ b/fs/jffs2/gc.c @@ -1171,7 +1171,7 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era uint32_t alloclen, offset, orig_end, orig_start; int ret = 0; unsigned char *comprbuf = NULL, *writebuf; - struct page *page; + struct folio *folio; unsigned char *pg_ptr; memset(&ri, 0, sizeof(ri)); @@ -1317,25 +1317,25 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era BUG_ON(start > orig_start); } - /* The rules state that we must obtain the page lock *before* f->sem, so + /* The rules state that we must obtain the folio lock *before* f->sem, so * drop f->sem temporarily. Since we also hold c->alloc_sem, nothing's * actually going to *change* so we're safe; we only allow reading. * * It is important to note that jffs2_write_begin() will ensure that its - * page is marked Uptodate before allocating space. That means that if we - * end up here trying to GC the *same* page that jffs2_write_begin() is - * trying to write out, read_cache_page() will not deadlock. */ + * folio is marked uptodate before allocating space. That means that if we + * end up here trying to GC the *same* folio that jffs2_write_begin() is + * trying to write out, read_cache_folio() will not deadlock. */ mutex_unlock(&f->sem); - page = read_cache_page(inode->i_mapping, start >> PAGE_SHIFT, + folio = read_cache_folio(inode->i_mapping, start >> PAGE_SHIFT, __jffs2_read_folio, NULL); - if (IS_ERR(page)) { - pr_warn("read_cache_page() returned error: %ld\n", - PTR_ERR(page)); + if (IS_ERR(folio)) { + pr_warn("read_cache_folio() returned error: %ld\n", + PTR_ERR(folio)); mutex_lock(&f->sem); - return PTR_ERR(page); + return PTR_ERR(folio); } - pg_ptr = kmap(page); + pg_ptr = kmap_local_folio(folio, 0); mutex_lock(&f->sem); offset = start; @@ -1400,7 +1400,6 @@ static int jffs2_garbage_collect_dnode(struct jffs2_sb_info *c, struct jffs2_era } } - kunmap(page); - put_page(page); + folio_release_kmap(folio, pg_ptr); return ret; }
Call read_cache_folio() instead of read_cache_page() to get the folio containing the page. No attempt is made here to support large folios as I assume that will never be interesting for jffs2. Includes a switch from kmap to kmap_local which looks safe. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> --- fs/jffs2/gc.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)