On Wed, Nov 19, 2014 at 10:45:33PM -0800, Jaegeuk Kim wrote: > On Thu, Nov 20, 2014 at 03:04:10PM +0900, Changman Lee wrote: > > Hi Jaegeuk, > > > > We should call flush_dcache_page before kunmap because the purpose of the > > cache flush is to address aliasing problem related to virtual address. > > Oh, I just followed zero_user_segments below. > > static inline void zero_user_segments(struct page *page, > unsigned start1, unsigned end1, > unsigned start2, unsigned end2) > { > void *kaddr = kmap_atomic(page); > > BUG_ON(end1 > PAGE_SIZE || end2 > PAGE_SIZE); > > if (end1 > start1) > memset(kaddr + start1, 0, end1 - start1); > > if (end2 > start2) > memset(kaddr + start2, 0, end2 - start2); > > kunmap_atomic(kaddr); > flush_dcache_page(page); > } > > Is this a wrong reference? Or, a bug? >
Well.. Data in cache only have to be flushed until before other users read the data. If so, it's not a bug. > Anyway I modified as below. > > Thanks, > > >From 7cb7b27c8cd2efc8a31d79239bef5b41c6e79216 Mon Sep 17 00:00:00 2001 > From: Jaegeuk Kim <jaeg...@kernel.org> > Date: Tue, 18 Nov 2014 10:50:21 -0800 > Subject: [PATCH] f2fs: call flush_dcache_page when the page was updated > > Whenever f2fs updates mapped pages, it needs to call flush_dcache_page. > > Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > --- > fs/f2fs/dir.c | 7 ++++++- > fs/f2fs/inline.c | 2 ++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c > index 5a49995..fabf4ee 100644 > --- a/fs/f2fs/dir.c > +++ b/fs/f2fs/dir.c > @@ -287,8 +287,10 @@ void f2fs_set_link(struct inode *dir, struct > f2fs_dir_entry *de, > f2fs_wait_on_page_writeback(page, type); > de->ino = cpu_to_le32(inode->i_ino); > set_de_type(de, inode); > - if (!f2fs_has_inline_dentry(dir)) > + if (!f2fs_has_inline_dentry(dir)) { > + flush_dcache_page(page); > kunmap(page); > + } > set_page_dirty(page); > dir->i_mtime = dir->i_ctime = CURRENT_TIME; > mark_inode_dirty(dir); > @@ -365,6 +367,7 @@ static int make_empty_dir(struct inode *inode, > make_dentry_ptr(&d, (void *)dentry_blk, 1); > do_make_empty_dir(inode, parent, &d); > > + flush_dcache_page(dentry_page); > kunmap_atomic(dentry_blk); > > set_page_dirty(dentry_page); > @@ -578,6 +581,7 @@ fail: > update_inode_page(dir); > clear_inode_flag(F2FS_I(dir), FI_UPDATE_DIR); > } > + flush_dcache_page(dentry_page); > kunmap(dentry_page); > f2fs_put_page(dentry_page, 1); > return err; > @@ -660,6 +664,7 @@ void f2fs_delete_entry(struct f2fs_dir_entry *dentry, > struct page *page, > bit_pos = find_next_bit_le(&dentry_blk->dentry_bitmap, > NR_DENTRY_IN_BLOCK, > 0); > + flush_dcache_page(page); > kunmap(page); /* kunmap - pair of f2fs_find_entry */ > set_page_dirty(page); > > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > index f26fb87..4291c1f 100644 > --- a/fs/f2fs/inline.c > +++ b/fs/f2fs/inline.c > @@ -106,6 +106,7 @@ int f2fs_convert_inline_page(struct dnode_of_data *dn, > struct page *page) > src_addr = inline_data_addr(dn->inode_page); > dst_addr = kmap_atomic(page); > memcpy(dst_addr, src_addr, MAX_INLINE_DATA); > + flush_dcache_page(page); > kunmap_atomic(dst_addr); > SetPageUptodate(page); > no_update: > @@ -357,6 +358,7 @@ static int f2fs_convert_inline_dir(struct inode *dir, > struct page *ipage, > memcpy(dentry_blk->filename, inline_dentry->filename, > NR_INLINE_DENTRY * F2FS_SLOT_LEN); > > + flush_dcache_page(page); > kunmap_atomic(dentry_blk); > SetPageUptodate(page); > set_page_dirty(page); > -- > 2.1.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/