Messages in this thread | | | Date | Fri, 27 Oct 2017 12:56:32 +0200 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] f2fs: fix to keep backward compatibility of flexible inline xattr feature |
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On 10/27, Chao Yu wrote: > On 2017/10/26 22:05, Jaegeuk Kim wrote: > > On 10/26, Chao Yu wrote: > >> On 2017/10/26 19:52, Jaegeuk Kim wrote: > >>> On 10/26, Chao Yu wrote: > >>>> Hi Jaegeuk, > >>>> > >>>> On 2017/10/26 18:02, Jaegeuk Kim wrote: > >>>>> Hi Chao, > >>>>> > >>>>> On 10/26, Jaegeuk Kim wrote: > >>>>>> On 10/26, Chao Yu wrote: > >>>>>>> Hi Jaegeuk, > >>>>>>> > >>>>>>> On 2017/10/26 16:42, Jaegeuk Kim wrote: > >>>>>>>> Hi Chao, > >>>>>>>> > >>>>>>>> It seems this is a critical problem, so let me integrate this patch with your > >>>>>>>> initial patch "f2fs: support flexible inline xattr size". > >>>>>>>> Let me know, if you have any other concern. > >>>>>>> > >>>>>>> Better. ;) > >>>>>>> > >>>>>>> Please add commit message of this patch into initial patch "f2fs: support > >>>>>>> flexible inline xattr size". > >>>>> > >>>>> BTW, I read the patch again, and couldn't catch the problem actually. > >>>>> We didn't assign inline_xattr all the time, instead do if inline_xattr > >>>> > >>>> But you can see, MAX_INLINE_DATA is calculated as below, in where we will always > >>>> reserve F2FS_INLINE_XATTR_ADDRS of 200 bytes, now we will change > >>>> F2FS_INLINE_XATTR_ADDRS to F2FS_INLINE_XATTR_ADDRS(inode) which is an flexible > >>>> size, so MAX_INLINE_DATA could be calculated to expand 200 bytes than before, > >>> > >>> That doesn't mean inline_addr is starting after 200 bytes. We're getting the > >>> address only if inline_xattr is set, no? The below size seems reserving the > >> > >> This isn't about inline_xattr_addr, it is about MAX_INLINE_DATA size calculation. > >> > >> For example, in old image, inode is with inline_{data,dentry} flag, but without > >> inline_xattr flag, it will only use 3688 - 200 bytes for storing inline data/dents, > >> which means, it reserves 200 bytes. > >> > >> If we update kernel, get_inline_xattr_addrs will return 0 if inline_xattr flag is not > >> set, so MAX_INLINE_DATA will be 3688, then inline_dentry page layout will change. > > > > Thanks. This makes much clear to me. It seems we need to handle directory only. > > Could you please check the dev-test branches in f2fs and f2fs-tools? > > This is a little complicated, as for non-inline_{data,dentry} inode, we will get > addrs number in inode by: > > static inline unsigned int addrs_per_inode(struct inode *inode) > { > if (f2fs_has_inline_xattr(inode)) > return CUR_ADDRS_PER_INODE(inode) - F2FS_INLINE_XATTR_ADDRS; > return CUR_ADDRS_PER_INODE(inode); > } > > It only cares about this inode is inline_xattr or not, so, if we reserve 200 > bytes for dir inode, it will cause incompatibility. > > So we need add this logic into i_inline_xattr_size calculation? Such as: > > a. new_inode: > > if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)) { > f2fs_bug_on(sbi, !f2fs_has_extra_attr(inode)); > if (f2fs_has_inline_xattr) > xattr_size = sbi->inline_xattr_size; > } else if (f2fs_has_inline_xattr(inode) || > (f2fs_has_inline_dentry(inode) && S_ISDIR(inode->i_mode))) {
We don't need to check both of them. It'd be enough to check f2fs_has_inline_dentry(inode).
> xattr = DEFAULT_INLINE_XATTR_ADDRS > } > F2FS_I(inode)->i_inline_xattr_size = xattr_size; > > b. do_read_inode > > if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)) { > f2fs_bug_on(sbi, !f2fs_has_extra_attr(inode)); > fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size); > } else if (f2fs_has_inline_xattr(inode) || > (f2fs_has_inline_dentry(inode) && S_ISDIR(inode->i_mode)) {
Ditto.
I merged the change in dev-test, so could you check that out again? ;)
Thanks,
> fi->i_inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS; > } else { > /* > * Previous inline_data always reserved 200 bytes, even if > * inline_xattr is disabled. But only inline_data is safe > * to get back the space. > */ > fi->i_inline_xattr_size = 0; > } > > How about this? IMO, it's better to keep codes similar in between new_inode > and do_read_inode. :) > > Thanks, > > > > > Thanks, > > > >> > >> Thanks, > >> > >>> last 200 bytes which we just didn't use fully before. > >>> > >>> Thanks, > >>> > >>>> > >>>> It is okay for regular or symlink inode generated in old kernel to enlarge > >>>> MAX_INLINE_DATA in new kernel, as reserved 200 bytes in inode are zero all the > >>>> time, for directory, it will be problematic because our layout of inline > >>>> dentry page is fixed and calculated according to MAX_INLINE_DATA, so if > >>>> MAX_INLINE_DATA is enlarged, fields offset in dentry structure will relocate, > >>>> result in incompatibility. > >>>> > >>>> #define MAX_INLINE_DATA(inode) (sizeof(__le32) * \ > >>>> (CUR_ADDRS_PER_INODE(inode) - \ > >>>> DEF_INLINE_RESERVED_SIZE - \ > >>>> F2FS_INLINE_XATTR_ADDRS)) > >>>> > >>>>> is set. Have you done some tests with this? I'm failing tests with these > >>>>> changes. > >>>> > >>>> Oh, sorry, I just tested with this patch without the modification of f2fs-tools, > >>>> fstest didn't report any errors so far. > >>>> > >>>> Thanks, > >>>> > >>>>> > >>>>>>> > >>>>>>> And please fix related issue in f2fs-tools with below diff code: > >>>>>> > >>>>>> Okay, merged. > >>>>>> > >>>>>> Thanks, > >>>>>> > >>>>>>> > >>>>>>> --- > >>>>>>> include/f2fs_fs.h | 9 ++++++--- > >>>>>>> 1 file changed, 6 insertions(+), 3 deletions(-) > >>>>>>> > >>>>>>> diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h > >>>>>>> index 2db7495804fd..a0e15ba85d97 100644 > >>>>>>> --- a/include/f2fs_fs.h > >>>>>>> +++ b/include/f2fs_fs.h > >>>>>>> @@ -1047,11 +1047,14 @@ static inline int __get_extra_isize(struct f2fs_inode *inode) > >>>>>>> extern struct f2fs_configuration c; > >>>>>>> static inline int get_inline_xattr_addrs(struct f2fs_inode *inode) > >>>>>>> { > >>>>>>> - if (!(inode->i_inline & F2FS_INLINE_XATTR)) > >>>>>>> + if ((c.feature & cpu_to_le32(F2FS_FEATURE_EXTRA_ATTR)) && > >>>>>>> + (c.feature & cpu_to_le32(F2FS_FEATURE_FLEXIBLE_INLINE_XATTR))) > >>>>>>> + return le16_to_cpu(inode->i_inline_xattr_size); > >>>>>>> + else if (!(inode->i_inline & F2FS_INLINE_XATTR) && > >>>>>>> + (S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode))) > >>>>>>> return 0; > >>>>>>> - if (!(c.feature & cpu_to_le32(F2FS_FEATURE_FLEXIBLE_INLINE_XATTR))) > >>>>>>> + else > >>>>>>> return DEFAULT_INLINE_XATTR_ADDRS; > >>>>>>> - return le16_to_cpu(inode->i_inline_xattr_size); > >>>>>>> } > >>>>>>> > >>>>>>> #define get_extra_isize(node) __get_extra_isize(&node->i) > >>>>>>> -- > >>>>>>> > >>>>>>> Thanks, > >>>>>>> > >>>>>>>> > >>>>>>>> Thanks, > >>>>>>>> > >>>>>>>> On 10/25, Chao Yu wrote: > >>>>>>>>> Previously, in inode layout, we will always reserve 200 bytes for inline > >>>>>>>>> xattr space no matter the inode enables inline xattr feature or not, due > >>>>>>>>> to this reason, max inline size of inode is fixed, but now, if inline > >>>>>>>>> xattr is not enabled, max inline size of inode will be enlarged by 200 > >>>>>>>>> bytes, for regular and symlink inode, it will be safe to reuse resevered > >>>>>>>>> space as they are all zero, but for directory, we need to keep the > >>>>>>>>> reservation for stablizing directory structure. > >>>>>>>>> > >>>>>>>>> Reported-by: Sheng Yong <shengyong1@huawei.com> > >>>>>>>>> Signed-off-by: Chao Yu <yuchao0@huawei.com> > >>>>>>>>> --- > >>>>>>>>> fs/f2fs/f2fs.h | 5 +---- > >>>>>>>>> fs/f2fs/inode.c | 15 ++++++++++++--- > >>>>>>>>> fs/f2fs/namei.c | 2 ++ > >>>>>>>>> 3 files changed, 15 insertions(+), 7 deletions(-) > >>>>>>>>> > >>>>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > >>>>>>>>> index 2af1d31ae74b..7ddd0d085e3b 100644 > >>>>>>>>> --- a/fs/f2fs/f2fs.h > >>>>>>>>> +++ b/fs/f2fs/f2fs.h > >>>>>>>>> @@ -2393,10 +2393,7 @@ static inline int get_extra_isize(struct inode *inode) > >>>>>>>>> static inline int f2fs_sb_has_flexible_inline_xattr(struct super_block *sb); > >>>>>>>>> static inline int get_inline_xattr_addrs(struct inode *inode) > >>>>>>>>> { > >>>>>>>>> - if (!f2fs_has_inline_xattr(inode)) > >>>>>>>>> - return 0; > >>>>>>>>> - if (!f2fs_sb_has_flexible_inline_xattr(F2FS_I_SB(inode)->sb)) > >>>>>>>>> - return DEFAULT_INLINE_XATTR_ADDRS; > >>>>>>>>> + > >>>>>>>>> return F2FS_I(inode)->i_inline_xattr_size; > >>>>>>>>> } > >>>>>>>>> > >>>>>>>>> diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c > >>>>>>>>> index bb876737e653..7f31b22c9efa 100644 > >>>>>>>>> --- a/fs/f2fs/inode.c > >>>>>>>>> +++ b/fs/f2fs/inode.c > >>>>>>>>> @@ -232,10 +232,19 @@ static int do_read_inode(struct inode *inode) > >>>>>>>>> fi->i_extra_isize = f2fs_has_extra_attr(inode) ? > >>>>>>>>> le16_to_cpu(ri->i_extra_isize) : 0; > >>>>>>>>> > >>>>>>>>> - if (!f2fs_has_inline_xattr(inode)) > >>>>>>>>> - fi->i_inline_xattr_size = 0; > >>>>>>>>> - else if (f2fs_sb_has_flexible_inline_xattr(sbi->sb)) > >>>>>>>>> + /* > >>>>>>>>> + * Previously, we will always reserve DEFAULT_INLINE_XATTR_ADDRS size > >>>>>>>>> + * space for inline xattr datas, if inline xattr is not enabled, we > >>>>>>>>> + * can expect all zero in reserved area, so for regular or symlink, > >>>>>>>>> + * it will be safe to reuse reserved area, but for directory, we > >>>>>>>>> + * should keep the reservation for stablizing directory structure. > >>>>>>>>> + */ > >>>>>>>>> + if (f2fs_has_extra_attr(inode) && > >>>>>>>>> + f2fs_sb_has_flexible_inline_xattr(sbi->sb)) > >>>>>>>>> fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size); > >>>>>>>>> + else if (!f2fs_has_inline_xattr(inode) && > >>>>>>>>> + (S_ISREG(inode->i_mode) || S_ISLNK(inode->i_mode))) > >>>>>>>>> + fi->i_inline_xattr_size = 0; > >>>>>>>>> else > >>>>>>>>> fi->i_inline_xattr_size = DEFAULT_INLINE_XATTR_ADDRS; > >>>>>>>>> > >>>>>>>>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c > >>>>>>>>> index e6f86d5d97b9..a1c56a14c191 100644 > >>>>>>>>> --- a/fs/f2fs/namei.c > >>>>>>>>> +++ b/fs/f2fs/namei.c > >>>>>>>>> @@ -91,6 +91,8 @@ static struct inode *f2fs_new_inode(struct inode *dir, umode_t mode) > >>>>>>>>> f2fs_sb_has_flexible_inline_xattr(sbi->sb) && > >>>>>>>>> f2fs_has_inline_xattr(inode)) > >>>>>>>>> F2FS_I(inode)->i_inline_xattr_size = sbi->inline_xattr_size; > >>>>>>>>> + else > >>>>>>>>> + F2FS_I(inode)->i_inline_xattr_size = 0; > >>>>>>>>> > >>>>>>>>> if (test_opt(sbi, INLINE_DATA) && f2fs_may_inline_data(inode)) > >>>>>>>>> set_inode_flag(inode, FI_INLINE_DATA); > >>>>>>>>> -- > >>>>>>>>> 2.13.1.388.g69e6b9b4f4a9 > >>>>>>>> > >>>>>>>> . > >>>>>>>> > > > > . > >
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