| Message ID | 20210617151705.15367-2-alex.sierra@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Support DEVICE_GENERIC memory in migrate_vma_* | expand |
On Thu, Jun 17, 2021 at 10:16:58AM -0500, Alex Sierra wrote: > From: Ralph Campbell <rcampbell@nvidia.com> > > There are several places where ZONE_DEVICE struct pages assume a reference > count == 1 means the page is idle and free. Instead of open coding this, > add a helper function to hide this detail. > > v2: > [AS]: rename dax_layout_is_idle_page func to dax_page_unused > > Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> > Signed-off-by: Alex Sierra <alex.sierra@amd.com> > --- > fs/dax.c | 4 ++-- > fs/ext4/inode.c | 5 +---- > fs/xfs/xfs_file.c | 4 +--- > include/linux/dax.h | 10 ++++++++++ > 4 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 26d5dcd2d69e..321f4ddc6643 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); > + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); > WARN_ON_ONCE(page->mapping && page->mapping != mapping); > page->mapping = NULL; > page->index = 0; > @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - if (page_ref_count(page) > 1) > + if (!dax_layout_is_idle_page(page)) > return page; > } > return NULL; > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index c173c8405856..9ee00186412f 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3972,10 +3972,7 @@ int ext4_break_layouts(struct inode *inode) > if (!page) > return 0; > > - error = ___wait_var_event(&page->_refcount, > - atomic_read(&page->_refcount) == 1, > - TASK_INTERRUPTIBLE, 0, 0, > - ext4_wait_dax_page(ei)); > + error = dax_wait_page(ei, page, ext4_wait_dax_page); > } while (error == 0); > > return error; > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > index 5b0f93f73837..39565fe5f817 100644 > --- a/fs/xfs/xfs_file.c > +++ b/fs/xfs/xfs_file.c > @@ -782,9 +782,7 @@ xfs_break_dax_layouts( > return 0; > > *retry = true; > - return ___wait_var_event(&page->_refcount, > - atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, > - 0, 0, xfs_wait_dax_page(inode)); > + return dax_wait_page(inode, page, xfs_wait_dax_page); Mechanically, this looks like a straightforward replacement, so: Acked-by: Darrick J. Wong <djwong@kernel.org> --D > } > > int > diff --git a/include/linux/dax.h b/include/linux/dax.h > index b52f084aa643..8b5da1d60dbc 100644 > --- a/include/linux/dax.h > +++ b/include/linux/dax.h > @@ -243,6 +243,16 @@ static inline bool dax_mapping(struct address_space *mapping) > return mapping->host && IS_DAX(mapping->host); > } > > +static inline bool dax_page_unused(struct page *page) > +{ > + return page_ref_count(page) == 1; > +} > + > +#define dax_wait_page(_inode, _page, _wait_cb) \ > + ___wait_var_event(&(_page)->_refcount, \ > + dax_page_unused(_page), \ > + TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode)) > + > #ifdef CONFIG_DEV_DAX_HMEM_DEVICES > void hmem_register_device(int target_nid, struct resource *r); > #else > -- > 2.17.1 >
On Thu, Jun 17, 2021 at 10:16:58AM -0500, Alex Sierra wrote: > From: Ralph Campbell <rcampbell@nvidia.com> > > There are several places where ZONE_DEVICE struct pages assume a reference > count == 1 means the page is idle and free. Instead of open coding this, > add a helper function to hide this detail. > > v2: > [AS]: rename dax_layout_is_idle_page func to dax_page_unused Did you even compile test this? > Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> > Signed-off-by: Alex Sierra <alex.sierra@amd.com> > --- > fs/dax.c | 4 ++-- > fs/ext4/inode.c | 5 +---- > fs/xfs/xfs_file.c | 4 +--- > include/linux/dax.h | 10 ++++++++++ > 4 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/fs/dax.c b/fs/dax.c > index 26d5dcd2d69e..321f4ddc6643 100644 > --- a/fs/dax.c > +++ b/fs/dax.c > @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); > + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); Because you still use dax_layout_is_idle_page() here, not dax_page_unused()... > WARN_ON_ONCE(page->mapping && page->mapping != mapping); > page->mapping = NULL; > page->index = 0; > @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) > for_each_mapped_pfn(entry, pfn) { > struct page *page = pfn_to_page(pfn); > > - if (page_ref_count(page) > 1) > + if (!dax_layout_is_idle_page(page)) Here too. Cheers, Dave.
On 6/17/2021 6:52 PM, Dave Chinner wrote: > On Thu, Jun 17, 2021 at 10:16:58AM -0500, Alex Sierra wrote: >> From: Ralph Campbell <rcampbell@nvidia.com> >> >> There are several places where ZONE_DEVICE struct pages assume a reference >> count == 1 means the page is idle and free. Instead of open coding this, >> add a helper function to hide this detail. >> >> v2: >> [AS]: rename dax_layout_is_idle_page func to dax_page_unused > Did you even compile test this? Thanks for catching this Dave, my mistake, I was building without CONFIG_FS_DAX, as I was using DEVICE_GENERIC only. I'll send the corrected patch in replay. Regards, Alex Sierra > >> Signed-off-by: Ralph Campbell <rcampbell@nvidia.com> >> Signed-off-by: Alex Sierra <alex.sierra@amd.com> >> --- >> fs/dax.c | 4 ++-- >> fs/ext4/inode.c | 5 +---- >> fs/xfs/xfs_file.c | 4 +--- >> include/linux/dax.h | 10 ++++++++++ >> 4 files changed, 14 insertions(+), 9 deletions(-) >> >> diff --git a/fs/dax.c b/fs/dax.c >> index 26d5dcd2d69e..321f4ddc6643 100644 >> --- a/fs/dax.c >> +++ b/fs/dax.c >> @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, >> for_each_mapped_pfn(entry, pfn) { >> struct page *page = pfn_to_page(pfn); >> >> - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); >> + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); > Because you still use dax_layout_is_idle_page() here, not > dax_page_unused()... > >> WARN_ON_ONCE(page->mapping && page->mapping != mapping); >> page->mapping = NULL; >> page->index = 0; >> @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) >> for_each_mapped_pfn(entry, pfn) { >> struct page *page = pfn_to_page(pfn); >> >> - if (page_ref_count(page) > 1) >> + if (!dax_layout_is_idle_page(page)) > Here too. > > Cheers, > > Dave.
diff --git a/fs/dax.c b/fs/dax.c index 26d5dcd2d69e..321f4ddc6643 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -358,7 +358,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - WARN_ON_ONCE(trunc && page_ref_count(page) > 1); + WARN_ON_ONCE(trunc && !dax_layout_is_idle_page(page)); WARN_ON_ONCE(page->mapping && page->mapping != mapping); page->mapping = NULL; page->index = 0; @@ -372,7 +372,7 @@ static struct page *dax_busy_page(void *entry) for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); - if (page_ref_count(page) > 1) + if (!dax_layout_is_idle_page(page)) return page; } return NULL; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c173c8405856..9ee00186412f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3972,10 +3972,7 @@ int ext4_break_layouts(struct inode *inode) if (!page) return 0; - error = ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, - TASK_INTERRUPTIBLE, 0, 0, - ext4_wait_dax_page(ei)); + error = dax_wait_page(ei, page, ext4_wait_dax_page); } while (error == 0); return error; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 5b0f93f73837..39565fe5f817 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -782,9 +782,7 @@ xfs_break_dax_layouts( return 0; *retry = true; - return ___wait_var_event(&page->_refcount, - atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE, - 0, 0, xfs_wait_dax_page(inode)); + return dax_wait_page(inode, page, xfs_wait_dax_page); } int diff --git a/include/linux/dax.h b/include/linux/dax.h index b52f084aa643..8b5da1d60dbc 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -243,6 +243,16 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } +static inline bool dax_page_unused(struct page *page) +{ + return page_ref_count(page) == 1; +} + +#define dax_wait_page(_inode, _page, _wait_cb) \ + ___wait_var_event(&(_page)->_refcount, \ + dax_page_unused(_page), \ + TASK_INTERRUPTIBLE, 0, 0, _wait_cb(_inode)) + #ifdef CONFIG_DEV_DAX_HMEM_DEVICES void hmem_register_device(int target_nid, struct resource *r); #else