On Tue, Nov 26, 2013 at 5:36 AM, Dave Chinner <david@xxxxxxxxxxxxx> wrote:
> On Mon, Nov 25, 2013 at 07:32:32PM +0800, Zhi Yong Wu wrote:
>> From: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
>>
>> The function is used to create one O_TMPFILE file.
>>
>> http://oss.sgi.com/archives/xfs/2013-08/msg00339.html
>>
>> Signed-off-by: Zhi Yong Wu <wuzhy@xxxxxxxxxxxxxxxxxx>
>> ---
>> fs/xfs/xfs_inode.c | 129
>> ++++++++++++++++++++++++++++++++++++++++++++++
>> fs/xfs/xfs_inode.h | 2 +
>> fs/xfs/xfs_shared.h | 4 +-
>> fs/xfs/xfs_trans_resv.c | 35 ++++++++++++
>> fs/xfs/xfs_trans_resv.h | 2 +
>> fs/xfs/xfs_trans_space.h | 2 +
>> 6 files changed, 173 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>> index 1c23bdf..e1832de 100644
>> --- a/fs/xfs/xfs_inode.c
>> +++ b/fs/xfs/xfs_inode.c
>> @@ -1337,6 +1337,135 @@ xfs_create(
>> }
>>
>> int
>> +xfs_create_tmpfile(
>> + xfs_mount_t *mp,
>> + umode_t mode,
>> + dev_t rdev,
>> + xfs_inode_t **ipp)
>> +{
>> + struct xfs_inode *ip = NULL;
>> + struct xfs_trans *tp = NULL;
>> + int error;
>> + uint cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
>> + struct xfs_dquot *udqp = NULL;
>> + struct xfs_dquot *gdqp = NULL;
>> + struct xfs_dquot *pdqp = NULL;
>> + struct xfs_trans_res *tres;
>> + uint resblks;
>> +
>> + if (XFS_FORCED_SHUTDOWN(mp))
>> + return XFS_ERROR(EIO);
>> +
>> + /*
>> + * Make sure that we have allocated dquot(s) on disk.
>> + */
>> + error = xfs_qm_vop_dqalloc(NULL, mp, xfs_kuid_to_uid(current_fsuid()),
>> + xfs_kgid_to_gid(current_fsgid()),
>> + XFS_PROJID_DEFAULT,
>> + XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
>> + &udqp, &gdqp, &pdqp);
>> + if (error)
>> + return error;
>
> Is XFS_PROJID_DEFAULT correct here? If we are getting a parent inode
> from ->tmpfile, then this should be handled the same way as for
> xfs_create.
ok, will fix it.
>
>> +
>> + resblks = XFS_CREATE_TMPFILE_SPACE_RES(mp);
>> + tp = xfs_trans_alloc(mp, XFS_TRANS_CREATE_TMPFILE);
>> +
>> + /*
>> + * Initially assume that the file does not exist and
>> + * reserve the resources for that case. If that is not
>> + * the case we'll drop the one we have and get a more
>> + * appropriate transaction later.
>> + */
>> + tres = &M_RES(mp)->tr_create_tmpfile;
>> + error = xfs_trans_reserve(tp, tres, resblks, 0);
>> + if (error == ENOSPC) {
>> + /* flush outstanding delalloc blocks and retry */
>> + xfs_flush_inodes(mp);
>> + error = xfs_trans_reserve(tp, tres, resblks, 0);
>> + }
>> + if (error == ENOSPC) {
>> + /* No space at all so try a "no-allocation" reservation */
>> + resblks = 0;
>> + error = xfs_trans_reserve(tp, tres, 0, 0);
>> + }
>> + if (error) {
>> + cancel_flags = 0;
>> + goto out_trans_cancel;
>> + }
>
> I don't think this is necessary here. The ENOSPC flushing in
> xfs_create() is done to ensure we have space for directory block
> creation, not so much for inode allocation. Hence it doesn't make a
> lot of sense to have this here....
Good explaination, will fix it, thanks.
>
>> + /*
>> + * Reserve disk quota and the inode.
>> + */
>> + error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
>> + pdqp, resblks, 1, 0);
>> + if (error)
>> + goto out_trans_cancel;
>> +
>> + /*
>> + * A newly created regular or special file just has one directory
>> + * entry pointing to them, but a directory also the "." entry
>> + * pointing to itself.
>> + */
>> + error = xfs_dir_ialloc(&tp, NULL, mode, 1, rdev,
>> + XFS_PROJID_DEFAULT, resblks > 0,
>> + &ip, NULL);
>> + if (error) {
>> + if (error == ENOSPC)
>> + goto out_trans_cancel;
>> + goto out_trans_abort;
>> + }
>> +
>> + /*
>> + * If this is a synchronous mount, make sure that the
>> + * create transaction goes to disk before returning to
>> + * the user.
>> + */
>> + if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
>> + xfs_trans_set_sync(tp);
>
> I'm not sure that XFS_MOUNT_DIRSYNC shoul dbe checked here, as there
> is no directory operations to synchronise at all...
ok, will fix it.
>
>> +STATIC uint
>> +xfs_calc_icreate_tmpfile_reservation(xfs_mount_t *mp)
>> +{
>> + return XFS_DQUOT_LOGRES(mp) +
>> + xfs_calc_icreate_resv_alloc(mp) +
>> + xfs_calc_inode_res(mp, 1) +
>> + xfs_calc_buf_res(1, XFS_FSB_TO_B(mp, 1)) +
>> + xfs_calc_buf_res(2, mp->m_sb.sb_sectsize);
>> +}
>> +
>> +STATIC uint
>> +__xfs_calc_create_tmpfile_reservation(
>> + struct xfs_mount *mp)
>> +{
>> + return XFS_DQUOT_LOGRES(mp) +
>> + xfs_calc_create_resv_alloc(mp) +
>> + xfs_calc_inode_res(mp, 1) +
>> + xfs_calc_buf_res(1, XFS_FSB_TO_B(mp, 1)) +
>> + xfs_calc_buf_res(2, mp->m_sb.sb_sectsize);
>> +}
>
> What exactly is being modified here? All of the other reservations
> have comments explaining what each of the individual components of
> the reservation are. Yes, I can see that there's an inode, a
> filesystem block and 2 sectors being reserved, but what are they?
Will add some comments in next version.
>
> It's also double counting the XFS_DQUOT_LOGRES(), as they are
> accounted for in xfs_calc_[i]create_reservation().
I don't understand why you said it double counts XFS_DQUOT_LOGRES()? i
only see it is counted once. Can you say more details?
>
> Also, the directory create reservations are broken up into two
> components - the inode allocation and the common directory name
> creation component, and so the tmpfile reservation should probably
> be broken up the same way. i.e this:
>
>> +
>> +STATIC uint
>> +xfs_calc_create_tmpfile_reservation(
>> + struct xfs_mount *mp)
>> +{
>> + if (xfs_sb_version_hascrc(&mp->m_sb))
>> + return xfs_calc_icreate_tmpfile_reservation(mp);
>> + return __xfs_calc_create_tmpfile_reservation(mp);
>> +}
>
> Could simply be:
>
> STATIC uint
> xfs_calc_create_tmpfile_reservation(
> struct xfs_mount *mp)
> {
> uint res;
>
> if (xfs_sb_version_hascrc(&mp->m_sb))
> res = xfs_calc_icreate_resv_alloc(mp);
> else
> res = xfs_calc_create_resv_alloc(mp);
> return res + xfs_calc_iunlink_add_resv(mp);
> }
Good suggestion, will apply this.
>
>
>> diff --git a/fs/xfs/xfs_trans_space.h b/fs/xfs/xfs_trans_space.h
>> index 7d2c920..16fba89 100644
>> --- a/fs/xfs/xfs_trans_space.h
>> +++ b/fs/xfs/xfs_trans_space.h
>> @@ -61,6 +61,8 @@
>> (XFS_DAENTER_SPACE_RES(mp, XFS_ATTR_FORK) + XFS_B_TO_FSB(mp, v))
>> #define XFS_CREATE_SPACE_RES(mp,nl) \
>> (XFS_IALLOC_SPACE_RES(mp) + XFS_DIRENTER_SPACE_RES(mp,nl))
>> +#define XFS_CREATE_TMPFILE_SPACE_RES(mp) \
>> + XFS_IALLOC_SPACE_RES(mp)
>
> I wouldn't bother with this macro - just use XFS_IALLOC_SPACE_RES()
> directly.
ok, will remove this macro.
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
--
Regards,
Zhi Yong Wu
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