RE: [PATCH v5 7/7] fs/xfs: Add dax dedupe support
> -Original Message-
> From: Darrick J. Wong
> Subject: Re: [PATCH v5 7/7] fs/xfs: Add dax dedupe support
>
> On Tue, May 11, 2021 at 11:09:33AM +0800, Shiyang Ruan wrote:
> > Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
> > who are going to be deduped. After that, call compare range function
> > only when files are both DAX or not.
> >
> > Signed-off-by: Shiyang Ruan
> > ---
> > fs/xfs/xfs_file.c| 2 +-
> > fs/xfs/xfs_inode.c | 66
> +++-
> > fs/xfs/xfs_inode.h | 1 +
> > fs/xfs/xfs_reflink.c | 4 +--
> > 4 files changed, 69 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index
> > 38d8eca05aee..bd5002d38df4 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -823,7 +823,7 @@ xfs_wait_dax_page(
> > xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> > }
> >
> > -static int
> > +int
> > xfs_break_dax_layouts(
> > struct inode*inode,
> > bool*retry)
> > diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index
> > 0369eb22c1bb..0774b6e2b940 100644
> > --- a/fs/xfs/xfs_inode.c
> > +++ b/fs/xfs/xfs_inode.c
> > @@ -3711,6 +3711,64 @@ xfs_iolock_two_inodes_and_break_layout(
> > return 0;
> > }
> >
> > +static int
> > +xfs_mmaplock_two_inodes_and_break_dax_layout(
> > + struct inode*src,
> > + struct inode*dest)
>
> MMAPLOCK is an xfs_inode lock, so please pass those in here.
>
> > +{
> > + int error, attempts = 0;
> > + boolretry;
> > + struct xfs_inode*ip0, *ip1;
> > + struct page *page;
> > + struct xfs_log_item *lp;
> > +
> > + if (src > dest)
> > + swap(src, dest);
>
> The MMAPLOCK (and ILOCK) locking order is increasing inode number, not the
> address of the incore object. This is different (and not consistent
> with) i_rwsem/XFS_IOLOCK, but those are the rules.
Yes, I misunderstood here.
>
> > + ip0 = XFS_I(src);
> > + ip1 = XFS_I(dest);
> > +
> > +again:
> > + retry = false;
> > + /* Lock the first inode */
> > + xfs_ilock(ip0, XFS_MMAPLOCK_EXCL);
> > + error = xfs_break_dax_layouts(src, &retry);
> > + if (error || retry) {
> > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> > + goto again;
> > + }
> > +
> > + if (src == dest)
> > + return 0;
> > +
> > + /* Nested lock the second inode */
> > + lp = &ip0->i_itemp->ili_item;
> > + if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
> > + if (!xfs_ilock_nowait(ip1,
> > + xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
> > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> > + if ((++attempts % 5) == 0)
> > + delay(1); /* Don't just spin the CPU */
> > + goto again;
> > + }
> > + } else
> > + xfs_ilock(ip1, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
> > + /*
> > +* We cannot use xfs_break_dax_layouts() directly here because it may
> > +* need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
> > +* for this nested lock case.
> > +*/
> > + page = dax_layout_busy_page(dest->i_mapping);
> > + if (page) {
> > + if (page_ref_count(page) != 1) {
>
> This could be flattened to:
>
> if (page && page_ref_count(page) != 1) {
> ...
> }
OK.
--
Thanks,
Ruan Shiyang.
>
> --D
>
> > + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> > + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> > + goto again;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > /*
> > * Lock two inodes so that userspace cannot initiate I/O via file syscalls
> > or
> > * mmap activity.
> > @@ -3721,10 +3779,16 @@ xfs_ilock2_io_mmap(
> > struct xfs_inode*ip2)
> > {
> > int ret;
> > + struct inode*ino1 = VFS_I(ip1);
> > + struct inode*ino2 = VFS_I(ip2);
> >
> > - ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
> > + ret = xfs_iolock_two_inodes_and_break_layout(ino1, ino2);
> &
Re: [PATCH v5 7/7] fs/xfs: Add dax dedupe support
On Tue, May 11, 2021 at 11:09:33AM +0800, Shiyang Ruan wrote:
> Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
> who are going to be deduped. After that, call compare range function
> only when files are both DAX or not.
>
> Signed-off-by: Shiyang Ruan
> ---
> fs/xfs/xfs_file.c| 2 +-
> fs/xfs/xfs_inode.c | 66 +++-
> fs/xfs/xfs_inode.h | 1 +
> fs/xfs/xfs_reflink.c | 4 +--
> 4 files changed, 69 insertions(+), 4 deletions(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 38d8eca05aee..bd5002d38df4 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -823,7 +823,7 @@ xfs_wait_dax_page(
> xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
> }
>
> -static int
> +int
> xfs_break_dax_layouts(
> struct inode*inode,
> bool*retry)
> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
> index 0369eb22c1bb..0774b6e2b940 100644
> --- a/fs/xfs/xfs_inode.c
> +++ b/fs/xfs/xfs_inode.c
> @@ -3711,6 +3711,64 @@ xfs_iolock_two_inodes_and_break_layout(
> return 0;
> }
>
> +static int
> +xfs_mmaplock_two_inodes_and_break_dax_layout(
> + struct inode*src,
> + struct inode*dest)
MMAPLOCK is an xfs_inode lock, so please pass those in here.
> +{
> + int error, attempts = 0;
> + boolretry;
> + struct xfs_inode*ip0, *ip1;
> + struct page *page;
> + struct xfs_log_item *lp;
> +
> + if (src > dest)
> + swap(src, dest);
The MMAPLOCK (and ILOCK) locking order is increasing inode number, not
the address of the incore object. This is different (and not consistent
with) i_rwsem/XFS_IOLOCK, but those are the rules.
> + ip0 = XFS_I(src);
> + ip1 = XFS_I(dest);
> +
> +again:
> + retry = false;
> + /* Lock the first inode */
> + xfs_ilock(ip0, XFS_MMAPLOCK_EXCL);
> + error = xfs_break_dax_layouts(src, &retry);
> + if (error || retry) {
> + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> + goto again;
> + }
> +
> + if (src == dest)
> + return 0;
> +
> + /* Nested lock the second inode */
> + lp = &ip0->i_itemp->ili_item;
> + if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
> + if (!xfs_ilock_nowait(ip1,
> + xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
> + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> + if ((++attempts % 5) == 0)
> + delay(1); /* Don't just spin the CPU */
> + goto again;
> + }
> + } else
> + xfs_ilock(ip1, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
> + /*
> + * We cannot use xfs_break_dax_layouts() directly here because it may
> + * need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
> + * for this nested lock case.
> + */
> + page = dax_layout_busy_page(dest->i_mapping);
> + if (page) {
> + if (page_ref_count(page) != 1) {
This could be flattened to:
if (page && page_ref_count(page) != 1) {
...
}
--D
> + xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
> + xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
> + goto again;
> + }
> + }
> +
> + return 0;
> +}
> +
> /*
> * Lock two inodes so that userspace cannot initiate I/O via file syscalls or
> * mmap activity.
> @@ -3721,10 +3779,16 @@ xfs_ilock2_io_mmap(
> struct xfs_inode*ip2)
> {
> int ret;
> + struct inode*ino1 = VFS_I(ip1);
> + struct inode*ino2 = VFS_I(ip2);
>
> - ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
> + ret = xfs_iolock_two_inodes_and_break_layout(ino1, ino2);
> if (ret)
> return ret;
> +
> + if (IS_DAX(ino1) && IS_DAX(ino2))
> + return xfs_mmaplock_two_inodes_and_break_dax_layout(ino1, ino2);
> +
> if (ip1 == ip2)
> xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
> else
> diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
> index ca826cfba91c..2d0b344fb100 100644
> --- a/fs/xfs/xfs_inode.h
> +++ b/fs/xfs/xfs_inode.h
> @@ -457,6 +457,7 @@ enum xfs_prealloc_flags {
>
> int xfs_update_prealloc_flags(struct xfs_inode *ip,
> enum xfs_prealloc_flags flags);
> +int xfs_break_dax_layouts(struct inode *inode, bool *retry);
> int xfs_break_layouts(struct inode *inode, uint *iolock,
> enum layout_break_reason reason);
>
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index 9a780948dbd0..ff308304c5cd 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1324,8 +1324,8 @@ xfs_reflink_remap_prep(
> if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
> goto
[PATCH v5 7/7] fs/xfs: Add dax dedupe support
Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files
who are going to be deduped. After that, call compare range function
only when files are both DAX or not.
Signed-off-by: Shiyang Ruan
---
fs/xfs/xfs_file.c| 2 +-
fs/xfs/xfs_inode.c | 66 +++-
fs/xfs/xfs_inode.h | 1 +
fs/xfs/xfs_reflink.c | 4 +--
4 files changed, 69 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 38d8eca05aee..bd5002d38df4 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -823,7 +823,7 @@ xfs_wait_dax_page(
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
}
-static int
+int
xfs_break_dax_layouts(
struct inode*inode,
bool*retry)
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 0369eb22c1bb..0774b6e2b940 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3711,6 +3711,64 @@ xfs_iolock_two_inodes_and_break_layout(
return 0;
}
+static int
+xfs_mmaplock_two_inodes_and_break_dax_layout(
+ struct inode*src,
+ struct inode*dest)
+{
+ int error, attempts = 0;
+ boolretry;
+ struct xfs_inode*ip0, *ip1;
+ struct page *page;
+ struct xfs_log_item *lp;
+
+ if (src > dest)
+ swap(src, dest);
+ ip0 = XFS_I(src);
+ ip1 = XFS_I(dest);
+
+again:
+ retry = false;
+ /* Lock the first inode */
+ xfs_ilock(ip0, XFS_MMAPLOCK_EXCL);
+ error = xfs_break_dax_layouts(src, &retry);
+ if (error || retry) {
+ xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
+ goto again;
+ }
+
+ if (src == dest)
+ return 0;
+
+ /* Nested lock the second inode */
+ lp = &ip0->i_itemp->ili_item;
+ if (lp && test_bit(XFS_LI_IN_AIL, &lp->li_flags)) {
+ if (!xfs_ilock_nowait(ip1,
+ xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1))) {
+ xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
+ if ((++attempts % 5) == 0)
+ delay(1); /* Don't just spin the CPU */
+ goto again;
+ }
+ } else
+ xfs_ilock(ip1, xfs_lock_inumorder(XFS_MMAPLOCK_EXCL, 1));
+ /*
+* We cannot use xfs_break_dax_layouts() directly here because it may
+* need to unlock & lock the XFS_MMAPLOCK_EXCL which is not suitable
+* for this nested lock case.
+*/
+ page = dax_layout_busy_page(dest->i_mapping);
+ if (page) {
+ if (page_ref_count(page) != 1) {
+ xfs_iunlock(ip1, XFS_MMAPLOCK_EXCL);
+ xfs_iunlock(ip0, XFS_MMAPLOCK_EXCL);
+ goto again;
+ }
+ }
+
+ return 0;
+}
+
/*
* Lock two inodes so that userspace cannot initiate I/O via file syscalls or
* mmap activity.
@@ -3721,10 +3779,16 @@ xfs_ilock2_io_mmap(
struct xfs_inode*ip2)
{
int ret;
+ struct inode*ino1 = VFS_I(ip1);
+ struct inode*ino2 = VFS_I(ip2);
- ret = xfs_iolock_two_inodes_and_break_layout(VFS_I(ip1), VFS_I(ip2));
+ ret = xfs_iolock_two_inodes_and_break_layout(ino1, ino2);
if (ret)
return ret;
+
+ if (IS_DAX(ino1) && IS_DAX(ino2))
+ return xfs_mmaplock_two_inodes_and_break_dax_layout(ino1, ino2);
+
if (ip1 == ip2)
xfs_ilock(ip1, XFS_MMAPLOCK_EXCL);
else
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index ca826cfba91c..2d0b344fb100 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -457,6 +457,7 @@ enum xfs_prealloc_flags {
intxfs_update_prealloc_flags(struct xfs_inode *ip,
enum xfs_prealloc_flags flags);
+intxfs_break_dax_layouts(struct inode *inode, bool *retry);
intxfs_break_layouts(struct inode *inode, uint *iolock,
enum layout_break_reason reason);
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 9a780948dbd0..ff308304c5cd 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1324,8 +1324,8 @@ xfs_reflink_remap_prep(
if (XFS_IS_REALTIME_INODE(src) || XFS_IS_REALTIME_INODE(dest))
goto out_unlock;
- /* Don't share DAX file data for now. */
- if (IS_DAX(inode_in) || IS_DAX(inode_out))
+ /* Don't share DAX file data with non-DAX file. */
+ if (IS_DAX(inode_in) != IS_DAX(inode_out))
goto out_unlock;
if (!IS_DAX(inode_in))
--
2.31.1
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