| Message ID | 20210924130959.2695749-4-ruansy.fnst@fujitsu.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fsdax: introduce fs query to support reflink | expand |
On Fri, Sep 24, 2021 at 09:09:54PM +0800, Shiyang Ruan wrote: > memory_failure_dev_pagemap code is a bit complex before introduce RMAP > feature for fsdax. So it is needed to factor some helper functions to > simplify these code. > > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> This looks like a reasonable hoist... Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > mm/memory-failure.c | 140 ++++++++++++++++++++++++-------------------- > 1 file changed, 76 insertions(+), 64 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 54879c339024..8ff9b52823c0 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1430,6 +1430,79 @@ static int try_to_split_thp_page(struct page *page, const char *msg) > return 0; > } > > +static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, > + struct address_space *mapping, pgoff_t index, int flags) > +{ > + struct to_kill *tk; > + unsigned long size = 0; > + > + list_for_each_entry(tk, to_kill, nd) > + if (tk->size_shift) > + size = max(size, 1UL << tk->size_shift); > + if (size) { > + /* > + * Unmap the largest mapping to avoid breaking up device-dax > + * mappings which are constant size. The actual size of the > + * mapping being torn down is communicated in siginfo, see > + * kill_proc() > + */ > + loff_t start = (index << PAGE_SHIFT) & ~(size - 1); > + > + unmap_mapping_range(mapping, start, size, 0); > + } > + > + kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags); > +} > + > +static int mf_generic_kill_procs(unsigned long long pfn, int flags, > + struct dev_pagemap *pgmap) > +{ > + struct page *page = pfn_to_page(pfn); > + LIST_HEAD(to_kill); > + dax_entry_t cookie; > + > + /* > + * Prevent the inode from being freed while we are interrogating > + * the address_space, typically this would be handled by > + * lock_page(), but dax pages do not use the page lock. This > + * also prevents changes to the mapping of this pfn until > + * poison signaling is complete. > + */ > + cookie = dax_lock_page(page); > + if (!cookie) > + return -EBUSY; > + > + if (hwpoison_filter(page)) > + return 0; > + > + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { > + /* > + * TODO: Handle HMM pages which may need coordination > + * with device-side memory. > + */ > + return -EBUSY; > + } > + > + /* > + * Use this flag as an indication that the dax page has been > + * remapped UC to prevent speculative consumption of poison. > + */ > + SetPageHWPoison(page); > + > + /* > + * Unlike System-RAM there is no possibility to swap in a > + * different physical page at a given virtual address, so all > + * userspace consumption of ZONE_DEVICE memory necessitates > + * SIGBUS (i.e. MF_MUST_KILL) > + */ > + flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; > + collect_procs(page, &to_kill, true); > + > + unmap_and_kill(&to_kill, pfn, page->mapping, page->index, flags); > + dax_unlock_page(page, cookie); > + return 0; > +} > + > static int memory_failure_hugetlb(unsigned long pfn, int flags) > { > struct page *p = pfn_to_page(pfn); > @@ -1519,12 +1592,8 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, > struct dev_pagemap *pgmap) > { > struct page *page = pfn_to_page(pfn); > - unsigned long size = 0; > - struct to_kill *tk; > LIST_HEAD(tokill); > - int rc = -EBUSY; > - loff_t start; > - dax_entry_t cookie; > + int rc = -ENXIO; > > if (flags & MF_COUNT_INCREASED) > /* > @@ -1533,67 +1602,10 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, > put_page(page); > > /* device metadata space is not recoverable */ > - if (!pgmap_pfn_valid(pgmap, pfn)) { > - rc = -ENXIO; > - goto out; > - } > - > - /* > - * Prevent the inode from being freed while we are interrogating > - * the address_space, typically this would be handled by > - * lock_page(), but dax pages do not use the page lock. This > - * also prevents changes to the mapping of this pfn until > - * poison signaling is complete. > - */ > - cookie = dax_lock_page(page); > - if (!cookie) > + if (!pgmap_pfn_valid(pgmap, pfn)) > goto out; > > - if (hwpoison_filter(page)) { > - rc = 0; > - goto unlock; > - } > - > - if (pgmap->type == MEMORY_DEVICE_PRIVATE) { > - /* > - * TODO: Handle HMM pages which may need coordination > - * with device-side memory. > - */ > - goto unlock; > - } > - > - /* > - * Use this flag as an indication that the dax page has been > - * remapped UC to prevent speculative consumption of poison. > - */ > - SetPageHWPoison(page); > - > - /* > - * Unlike System-RAM there is no possibility to swap in a > - * different physical page at a given virtual address, so all > - * userspace consumption of ZONE_DEVICE memory necessitates > - * SIGBUS (i.e. MF_MUST_KILL) > - */ > - flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; > - collect_procs(page, &tokill, flags & MF_ACTION_REQUIRED); > - > - list_for_each_entry(tk, &tokill, nd) > - if (tk->size_shift) > - size = max(size, 1UL << tk->size_shift); > - if (size) { > - /* > - * Unmap the largest mapping to avoid breaking up > - * device-dax mappings which are constant size. The > - * actual size of the mapping being torn down is > - * communicated in siginfo, see kill_proc() > - */ > - start = (page->index << PAGE_SHIFT) & ~(size - 1); > - unmap_mapping_range(page->mapping, start, size, 0); > - } > - kill_procs(&tokill, flags & MF_MUST_KILL, false, pfn, flags); > - rc = 0; > -unlock: > - dax_unlock_page(page, cookie); > + rc = mf_generic_kill_procs(pfn, flags, pgmap); > out: > /* drop pgmap ref acquired in caller */ > put_dev_pagemap(pgmap); > -- > 2.33.0 > > >
On Fri, Sep 24, 2021 at 09:09:54PM +0800, Shiyang Ruan wrote: > memory_failure_dev_pagemap code is a bit complex before introduce RMAP > feature for fsdax. So it is needed to factor some helper functions to > simplify these code. > > Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> > --- > mm/memory-failure.c | 140 ++++++++++++++++++++++++-------------------- > 1 file changed, 76 insertions(+), 64 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 54879c339024..8ff9b52823c0 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1430,6 +1430,79 @@ static int try_to_split_thp_page(struct page *page, const char *msg) > return 0; > } > > +static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, > + struct address_space *mapping, pgoff_t index, int flags) > +{ > + struct to_kill *tk; > + unsigned long size = 0; > + > + list_for_each_entry(tk, to_kill, nd) > + if (tk->size_shift) > + size = max(size, 1UL << tk->size_shift); > + if (size) { Nit: an empty line here would be nice for readability. > + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { > + /* > + * TODO: Handle HMM pages which may need coordination > + * with device-side memory. > + */ > + return -EBUSY; We've got rid of the HMM terminology for device private memory, so I'd reword this update the comment to follow that while you're at it. Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 54879c339024..8ff9b52823c0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1430,6 +1430,79 @@ static int try_to_split_thp_page(struct page *page, const char *msg) return 0; } +static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, + struct address_space *mapping, pgoff_t index, int flags) +{ + struct to_kill *tk; + unsigned long size = 0; + + list_for_each_entry(tk, to_kill, nd) + if (tk->size_shift) + size = max(size, 1UL << tk->size_shift); + if (size) { + /* + * Unmap the largest mapping to avoid breaking up device-dax + * mappings which are constant size. The actual size of the + * mapping being torn down is communicated in siginfo, see + * kill_proc() + */ + loff_t start = (index << PAGE_SHIFT) & ~(size - 1); + + unmap_mapping_range(mapping, start, size, 0); + } + + kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags); +} + +static int mf_generic_kill_procs(unsigned long long pfn, int flags, + struct dev_pagemap *pgmap) +{ + struct page *page = pfn_to_page(pfn); + LIST_HEAD(to_kill); + dax_entry_t cookie; + + /* + * Prevent the inode from being freed while we are interrogating + * the address_space, typically this would be handled by + * lock_page(), but dax pages do not use the page lock. This + * also prevents changes to the mapping of this pfn until + * poison signaling is complete. + */ + cookie = dax_lock_page(page); + if (!cookie) + return -EBUSY; + + if (hwpoison_filter(page)) + return 0; + + if (pgmap->type == MEMORY_DEVICE_PRIVATE) { + /* + * TODO: Handle HMM pages which may need coordination + * with device-side memory. + */ + return -EBUSY; + } + + /* + * Use this flag as an indication that the dax page has been + * remapped UC to prevent speculative consumption of poison. + */ + SetPageHWPoison(page); + + /* + * Unlike System-RAM there is no possibility to swap in a + * different physical page at a given virtual address, so all + * userspace consumption of ZONE_DEVICE memory necessitates + * SIGBUS (i.e. MF_MUST_KILL) + */ + flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; + collect_procs(page, &to_kill, true); + + unmap_and_kill(&to_kill, pfn, page->mapping, page->index, flags); + dax_unlock_page(page, cookie); + return 0; +} + static int memory_failure_hugetlb(unsigned long pfn, int flags) { struct page *p = pfn_to_page(pfn); @@ -1519,12 +1592,8 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, struct dev_pagemap *pgmap) { struct page *page = pfn_to_page(pfn); - unsigned long size = 0; - struct to_kill *tk; LIST_HEAD(tokill); - int rc = -EBUSY; - loff_t start; - dax_entry_t cookie; + int rc = -ENXIO; if (flags & MF_COUNT_INCREASED) /* @@ -1533,67 +1602,10 @@ static int memory_failure_dev_pagemap(unsigned long pfn, int flags, put_page(page); /* device metadata space is not recoverable */ - if (!pgmap_pfn_valid(pgmap, pfn)) { - rc = -ENXIO; - goto out; - } - - /* - * Prevent the inode from being freed while we are interrogating - * the address_space, typically this would be handled by - * lock_page(), but dax pages do not use the page lock. This - * also prevents changes to the mapping of this pfn until - * poison signaling is complete. - */ - cookie = dax_lock_page(page); - if (!cookie) + if (!pgmap_pfn_valid(pgmap, pfn)) goto out; - if (hwpoison_filter(page)) { - rc = 0; - goto unlock; - } - - if (pgmap->type == MEMORY_DEVICE_PRIVATE) { - /* - * TODO: Handle HMM pages which may need coordination - * with device-side memory. - */ - goto unlock; - } - - /* - * Use this flag as an indication that the dax page has been - * remapped UC to prevent speculative consumption of poison. - */ - SetPageHWPoison(page); - - /* - * Unlike System-RAM there is no possibility to swap in a - * different physical page at a given virtual address, so all - * userspace consumption of ZONE_DEVICE memory necessitates - * SIGBUS (i.e. MF_MUST_KILL) - */ - flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; - collect_procs(page, &tokill, flags & MF_ACTION_REQUIRED); - - list_for_each_entry(tk, &tokill, nd) - if (tk->size_shift) - size = max(size, 1UL << tk->size_shift); - if (size) { - /* - * Unmap the largest mapping to avoid breaking up - * device-dax mappings which are constant size. The - * actual size of the mapping being torn down is - * communicated in siginfo, see kill_proc() - */ - start = (page->index << PAGE_SHIFT) & ~(size - 1); - unmap_mapping_range(page->mapping, start, size, 0); - } - kill_procs(&tokill, flags & MF_MUST_KILL, false, pfn, flags); - rc = 0; -unlock: - dax_unlock_page(page, cookie); + rc = mf_generic_kill_procs(pfn, flags, pgmap); out: /* drop pgmap ref acquired in caller */ put_dev_pagemap(pgmap);
memory_failure_dev_pagemap code is a bit complex before introduce RMAP feature for fsdax. So it is needed to factor some helper functions to simplify these code. Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> --- mm/memory-failure.c | 140 ++++++++++++++++++++++++-------------------- 1 file changed, 76 insertions(+), 64 deletions(-)