Hi Jaegeuk, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaeg...@kernel.org] > Sent: Tuesday, March 10, 2015 12:16 AM > To: Chao Yu > Cc: 'Changman Lee'; linux-f2fs-de...@lists.sourceforge.net; > linux-kernel@vger.kernel.org > Subject: Re: [PATCH] f2fs: fix to truncate inline data past EOF > > Hi Chao, > > On Mon, Mar 09, 2015 at 04:30:32PM +0800, Chao Yu wrote: > > Hi Jaegeuk, > > > > > -----Original Message----- > > > From: Jaegeuk Kim [mailto:jaeg...@kernel.org] > > > Sent: Monday, March 09, 2015 11:49 AM > > > To: Chao Yu > > > Cc: 'Changman Lee'; linux-f2fs-de...@lists.sourceforge.net; > > > linux-kernel@vger.kernel.org > > > Subject: Re: [PATCH] f2fs: fix to truncate inline data past EOF > > > > > > Hi Chao, > > > > > > > > > On Mon, Mar 09, 2015 at 10:24:35AM +0800, Chao Yu wrote: > > > > Hi Jaegeuk, > > > > > > > > > -----Original Message----- > > > > > From: Jaegeuk Kim [mailto:jaeg...@kernel.org] > > > > > Sent: Friday, March 06, 2015 5:34 AM > > > > > To: Chao Yu > > > > > Cc: Changman Lee; linux-f2fs-de...@lists.sourceforge.net; > > > > > linux-kernel@vger.kernel.org > > > > > Subject: Re: [PATCH] f2fs: fix to truncate inline data past EOF > > > > > > > > > > Hi Chao, > > > > > > > > > > On Thu, Mar 05, 2015 at 05:41:32PM +0800, Chao Yu wrote: > > > > > > Previously if inode is with inline data, we will try to invalid > > > > > > partial inline > > > > > > data in page #0 when we truncate size of inode in > > > > > > truncate_partial_data_page(). > > > > > > And then we set page #0 to dirty, after this we can synchronize > > > > > > inode page with > > > > > > page #0 at ->writepage(). > > > > > > > > > > > > But sometimes we will fail to operate page #0 in > > > > > > truncate_partial_data_page() > > > > > > due to below reason: > > > > > > a) if offset is zero, we will skip setting page #0 to dirty. > > > > > > b) if page #0 is not uptodate, we will fail to update it as it has > > > > > > no mapping > > > > > > data. > > > > > > > > > > > > So with following operations, we will meet recent data which should > > > > > > be > > > > > > truncated. > > > > > > > > > > > > 1.write inline data to file > > > > > > 2.sync first data page to inode page > > > > > > 3.truncate file size to 0 > > > > > > 4.truncate file size to max_inline_size > > > > > > 5.echo 1 > /proc/sys/vm/drop_caches > > > > > > 6.read file --> meet original inline data which is remained in > > > > > > inode page. > > > > > > > > > > > > This patch renames truncate_inline_data() to > > > > > > truncate_inline_inode() for code > > > > > > readability, then intruduces new truncate_inline_data() and use it > > > > > > to truncate > > > > > > inline data in page #0 and inode page in > > > > > > truncate_partial_data_page() for > > > > > > fixing. > > > > > > > > > > > > Signed-off-by: Chao Yu <chao2...@samsung.com> > > > > > > --- > > > > > > fs/f2fs/f2fs.h | 1 + > > > > > > fs/f2fs/file.c | 13 ++++++++----- > > > > > > fs/f2fs/inline.c | 57 > > > > > > +++++++++++++++++++++++++++++++++++++++++++++++++++----- > > > > > > 3 files changed, 61 insertions(+), 10 deletions(-) > > > > > > > > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > > > > index 511d6cd..55dbbe7 100644 > > > > > > --- a/fs/f2fs/f2fs.h > > > > > > +++ b/fs/f2fs/f2fs.h > > > > > > @@ -1754,6 +1754,7 @@ extern struct kmem_cache *inode_entry_slab; > > > > > > */ > > > > > > bool f2fs_may_inline(struct inode *); > > > > > > void read_inline_data(struct page *, struct page *); > > > > > > +int truncate_inline_data(struct inode *, u64 from); > > > > > > int f2fs_read_inline_data(struct inode *, struct page *); > > > > > > int f2fs_convert_inline_page(struct dnode_of_data *, struct page > > > > > > *); > > > > > > int f2fs_convert_inline_inode(struct inode *); > > > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > > > > > index f1341c7..6c4443e 100644 > > > > > > --- a/fs/f2fs/file.c > > > > > > +++ b/fs/f2fs/file.c > > > > > > @@ -461,6 +461,9 @@ static int truncate_partial_data_page(struct > > > > > > inode *inode, u64 > from) > > > > > > unsigned offset = from & (PAGE_CACHE_SIZE - 1); > > > > > > struct page *page; > > > > > > > > > > > > + if (f2fs_has_inline_data(inode)) > > > > > > + return 0; > > > > > > + > > > > > > if (!offset) > > > > > > return 0; > > > > > > > > > > > > @@ -497,14 +500,14 @@ int truncate_blocks(struct inode *inode, u64 > > > > > > from, bool lock) > > > > > > if (lock) > > > > > > f2fs_lock_op(sbi); > > > > > > > > > > > > - ipage = get_node_page(sbi, inode->i_ino); > > > > > > - if (IS_ERR(ipage)) { > > > > > > - err = PTR_ERR(ipage); > > > > > > + if (f2fs_has_inline_data(inode)) { > > > > > > + err = truncate_inline_data(inode, from); > > > > > > goto out; > > > > > > } > > > > > > > > > > > > - if (f2fs_has_inline_data(inode)) { > > > > > > - f2fs_put_page(ipage, 1); > > > > > > + ipage = get_node_page(sbi, inode->i_ino); > > > > > > + if (IS_ERR(ipage)) { > > > > > > + err = PTR_ERR(ipage); > > > > > > goto out; > > > > > > } > > > > > > > > > > > > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > > > > > > index 4ba9732..a8189c92 100644 > > > > > > --- a/fs/f2fs/inline.c > > > > > > +++ b/fs/f2fs/inline.c > > > > > > @@ -50,10 +50,57 @@ void read_inline_data(struct page *page, struct > > > > > > page *ipage) > > > > > > SetPageUptodate(page); > > > > > > } > > > > > > > > > > > > -static void truncate_inline_data(struct page *ipage) > > > > > > +static void truncate_inline_inode(struct page *ipage, u64 from) > > > > > > { > > > > > > + void *addr = inline_data_addr(ipage); > > > > > > + > > > > > > f2fs_wait_on_page_writeback(ipage, NODE); > > > > > > - memset(inline_data_addr(ipage), 0, MAX_INLINE_DATA); > > > > > > + memset(addr + from, 0, MAX_INLINE_DATA - from); > > > > > > +} > > > > > > + > > > > > > +int truncate_inline_data(struct inode *inode, u64 from) > > > > > > +{ > > > > > > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > > > > > > + struct page *page, *ipage; > > > > > > + void *addr; > > > > > > + int err = 0; > > > > > > + > > > > > > + /* > > > > > > + * we should never truncate inline data past max inline data > > > > > > size, > > > > > > + * because we always convert inline inode to normal one before > > > > > > + * truncating real data if new size is past max inline data > > > > > > size. > > > > > > + */ > > > > > > + f2fs_bug_on(sbi, from > MAX_INLINE_DATA); > > > > > > + > > > > > > + if (from == MAX_INLINE_DATA) > > > > > > + return 0; > > > > > > + > > > > > > + page = grab_cache_page(inode->i_mapping, 0); > > > > > > + if (!page) > > > > > > + return -ENOMEM; > > > > > > > > > > Do we need to grab and read #0 page? > > > > > > > > No need to read #0 page, sorry for the mistake. > > > > > > > > > How about checking its cached page after on-disk truncation? > > > > > > > > > > 1. page = get_node_page() > > > > > 2. check_inline > > > > > 3. truncate_inline_inode > > > > > 4. f2fs_put_page(ipage) > > > > > > > > > > 5. truncate_partial_data_page(inode, from, force) > > > > > if (!offset && !force) > > > > > return 0; > > > > > > > > > > > + > > > > > > + ipage = get_node_page(sbi, inode->i_ino); > > > > > > + if (IS_ERR(ipage)) { > > > > > > + err = PTR_ERR(ipage); > > > > > > + goto out; > > > > > > + } > > > > > > + > > > > > > + if (!f2fs_has_inline_data(inode)) { > > > > > > + f2fs_put_page(ipage, 1); > > > > > > + goto out; > > > > > > + } > > > > > > + > > > > > > + truncate_inline_inode(ipage, from); > > > > > > + set_page_dirty(ipage); > > > > > > + > > > > > > + read_inline_data(page, ipage); > > > > > > + f2fs_put_page(ipage, 1); > > > > > > + > > > > > > + addr = inline_data_addr(page); > > > > > > + memset(addr + from, 0, MAX_INLINE_DATA - from); > > > > > > > > > > It needs to do likewise truncate_partial_data_page. > > > > > > > > Do you mean like this? > > > > > > I meant this. > > > > > > Anyway, I also wrote a patch about your testing scenario wrt inline_data. > > > So, let me submit the patch sooner or later to xfstests mailing list. > > > > Sounds good! :) > > > > > > > > Thanks, > > > > > > --- > > > fs/f2fs/f2fs.h | 1 + > > > fs/f2fs/file.c | 10 +++++++--- > > > fs/f2fs/inline.c | 12 +++++++----- > > > 3 files changed, 15 insertions(+), 8 deletions(-) > > > > > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > > > index 31b440e..b222b3a 100644 > > > --- a/fs/f2fs/f2fs.h > > > +++ b/fs/f2fs/f2fs.h > > > @@ -1760,6 +1760,7 @@ extern struct kmem_cache *inode_entry_slab; > > > */ > > > bool f2fs_may_inline(struct inode *); > > > void read_inline_data(struct page *, struct page *); > > > +void truncate_inline_inode(struct page *, u64); > > > int f2fs_read_inline_data(struct inode *, struct page *); > > > int f2fs_convert_inline_page(struct dnode_of_data *, struct page *); > > > int f2fs_convert_inline_inode(struct inode *); > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > > index f1341c7..ab249dd 100644 > > > --- a/fs/f2fs/file.c > > > +++ b/fs/f2fs/file.c > > > @@ -456,12 +456,12 @@ void truncate_data_blocks(struct dnode_of_data *dn) > > > truncate_data_blocks_range(dn, ADDRS_PER_BLOCK); > > > } > > > > > > -static int truncate_partial_data_page(struct inode *inode, u64 from) > > > +static int truncate_partial_data_page(struct inode *inode, u64 from, > > > bool force) > > > { > > > unsigned offset = from & (PAGE_CACHE_SIZE - 1); > > > struct page *page; > > > > > > - if (!offset) > > > + if (!offset && !force) > > > > We truncate on-disk inode page and #0 page separately, so IMO there is a > > very > > small chance the following issue will occur. > > > > (0 < truncated_size < MAX_INLINE_SIZE) > > ->f2fs_setattr > > ->truncate_setsize #0 page has been truncated partially > > ->f2fs_truncate > > ->truncate_blocks > > invalidate #0 page by reclaimer > > update #0 page with original data in > > inode page by reader > > truncate_setsize called > truncate_pagesize. > so #0 page was truncated successfully.
Yeah, but it's partially truncating as 0 < truncated_size < MAX_INLINE_SIZE, After truncating, we still keep [0, truncated_size) valid data in #0 page, and our #0 page status is uptodate | !dirty. So what I mean is that mm can reclaim this #0 page, then if someone else read the #0 page again, we will update the #0 page with original data in inode page since inode page haven't truncated yet. If this happened, if we don't truncate #0 page in following code of truncate_blocks, we will remain the original data for user, it's wrong. IMO, it's better to truncate inode page and #0 page together, or truncate #0 page in truncate_partial_data_page. How do you think? > > > ->truncate_inline_inode > > ->truncate_partial_data_page > > we will fail to truncate #0 page because we can't find valid > > blkaddr for > > #0 page in find_data_page(,,false) > > > > How about using find_data_page(,,true) to check weather this page is update > > or not > > for this condition. > > Oh, I realized that we don't need to call truncate_partial_data_page, since > the > cached #0 page was truncated already. We don't care about that. IMO, we should care about this #0 page if above example can happen. > So, do we need to add just truncate_inline_inode() like below? > > > > > > return 0; > > > > > > page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, false); > > > @@ -489,6 +489,7 @@ int truncate_blocks(struct inode *inode, u64 from, > > > bool lock) > > > pgoff_t free_from; > > > int count = 0, err = 0; > > > struct page *ipage; > > > + bool truncate_page = false; > > > > > > trace_f2fs_truncate_blocks_enter(inode, from); > > > > > > @@ -504,6 +505,9 @@ int truncate_blocks(struct inode *inode, u64 from, > > > bool lock) > > > } > > > > > > if (f2fs_has_inline_data(inode)) { > > > + truncate_inline_inode(ipage, from); > > > + set_page_dirty(ipage); > > > > If @from is the same as MAX_INLINE_DATA, we will change nothing in inode > > page, > > How about skipping set_page_dirty for inode page in this condition? > > Agreed. > How about adding this in truncate_inline_inode? > > if (from >= MAX_INLINE_DATA) > return; > ... > set_page_dirty(ipage); Yeah, that's good. And What I suggest is: bool truncate_inline_inode(struct page *ipage, u64 from) { /* * we should never truncate inline data past max inline data size, * because we always convert inline inode to normal one before * truncating real data if new size is past max inline data size. */ f2fs_bug_on(F2FS_P_SB(ipage), from > MAX_INLINE_DATA); if (from == MAX_INLINE_DATA) return false; ... return true; } in truncate_blocks() if (f2fs_has_inline_data(inode)) { if (truncate_inline_inode(ipage, from)) set_page_dirty(ipage); So by this way, we can distinguish between a bug and invalid truncating in truncate_inline_inode, and also we can avoid unneeded set_dirty_page for inode page in other call path. How do you think of this? > > Thanks, > > Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > --- > fs/f2fs/f2fs.h | 1 + > fs/f2fs/file.c | 1 + > fs/f2fs/inline.c | 16 +++++++++++----- > 3 files changed, 13 insertions(+), 5 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 511d6cd..5cd3a2f 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -1754,6 +1754,7 @@ extern struct kmem_cache *inode_entry_slab; > */ > bool f2fs_may_inline(struct inode *); > void read_inline_data(struct page *, struct page *); > +void truncate_inline_inode(struct page *, u64); > int f2fs_read_inline_data(struct inode *, struct page *); > int f2fs_convert_inline_page(struct dnode_of_data *, struct page *); > int f2fs_convert_inline_inode(struct inode *); > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > index f1341c7..b6b6a04 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -504,6 +504,7 @@ int truncate_blocks(struct inode *inode, u64 from, bool > lock) > } > > if (f2fs_has_inline_data(inode)) { > + truncate_inline_inode(ipage, from); > f2fs_put_page(ipage, 1); > goto out; > } > diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c > index 4ba9732..40bbf96 100644 > --- a/fs/f2fs/inline.c > +++ b/fs/f2fs/inline.c > @@ -50,10 +50,16 @@ void read_inline_data(struct page *page, struct page > *ipage) > SetPageUptodate(page); > } > > -static void truncate_inline_data(struct page *ipage) > +void truncate_inline_inode(struct page *ipage, u64 from) > { > + void *addr = inline_data_addr(ipage); > + > + if (from >= MAX_INLIE_DATA) > + return; > + > f2fs_wait_on_page_writeback(ipage, NODE); > - memset(inline_data_addr(ipage), 0, MAX_INLINE_DATA); > + memset(addr + from, 0, MAX_INLINE_DATA - from); > + set_page_dirty(ipage); > } > > int f2fs_read_inline_data(struct inode *inode, struct page *page) > @@ -131,7 +137,7 @@ no_update: > set_inode_flag(F2FS_I(dn->inode), FI_APPEND_WRITE); > > /* clear inline data and flag after data writeback */ > - truncate_inline_data(dn->inode_page); > + truncate_inline_inode(dn->inode_page, 0); > clear_out: > stat_dec_inline_inode(dn->inode); > f2fs_clear_inline_inode(dn->inode); > @@ -245,7 +251,7 @@ process_inline: > if (f2fs_has_inline_data(inode)) { > ipage = get_node_page(sbi, inode->i_ino); > f2fs_bug_on(sbi, IS_ERR(ipage)); > - truncate_inline_data(ipage); > + truncate_inline_inode(ipage, 0); > f2fs_clear_inline_inode(inode); > update_inode(inode, ipage); > f2fs_put_page(ipage, 1); > @@ -363,7 +369,7 @@ static int f2fs_convert_inline_dir(struct inode *dir, > struct page *ipage, > set_page_dirty(page); > > /* clear inline dir and flag after data writeback */ > - truncate_inline_data(ipage); > + truncate_inline_inode(ipage, 0); > > stat_dec_inline_dir(dir); > clear_inode_flag(F2FS_I(dir), FI_INLINE_DENTRY); > -- > 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/