| Message ID | 20220310140911.50924-4-chao.p.peng@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KVM: mm: fd-based approach for supporting KVM guest private memory | expand |
On Thu, Mar 10, 2022 at 10:09:01PM +0800, Chao Peng wrote: > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > It maintains a memfile_notifier list in shmem_inode_info structure and > implements memfile_pfn_ops callbacks defined by memfile_notifier. It > then exposes them to memfile_notifier via > shmem_get_memfile_notifier_info. > > We use SGP_NOALLOC in shmem_get_lock_pfn since the pages should be > allocated by userspace for private memory. If there is no pages > allocated at the offset then error should be returned so KVM knows that > the memory is not private memory. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > --- > include/linux/shmem_fs.h | 4 +++ > mm/shmem.c | 76 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 80 insertions(+) > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > index 2dde843f28ef..7bb16f2d2825 100644 > --- a/include/linux/shmem_fs.h > +++ b/include/linux/shmem_fs.h > @@ -9,6 +9,7 @@ > #include <linux/percpu_counter.h> > #include <linux/xattr.h> > #include <linux/fs_parser.h> > +#include <linux/memfile_notifier.h> > > /* inode in-kernel data */ > > @@ -28,6 +29,9 @@ struct shmem_inode_info { > struct simple_xattrs xattrs; /* list of xattrs */ > atomic_t stop_eviction; /* hold when working on inode */ > unsigned int xflags; /* shmem extended flags */ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct memfile_notifier_list memfile_notifiers; > +#endif > struct inode vfs_inode; > }; > > diff --git a/mm/shmem.c b/mm/shmem.c > index 9b31a7056009..7b43e274c9a2 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > return page ? page_folio(page) : NULL; > } > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > +{ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct shmem_inode_info *info = SHMEM_I(inode); > + > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > +#endif > +} *notify_populate(), not fallocate. This is a notification that a range has been populated, not that the fallocate() syscall was run to populate the backing store of a file. i.e. fallocate is the name of a userspace filesystem API that can be used to manipulate the backing store of a file in various ways. It can both populate and punch away the backing store of a file, and some operations that fallocate() can run will do both (e.g. FALLOC_FL_ZERO_RANGE) and so could generate both notify_invalidate() and a notify_populate() events. Hence "fallocate" as an internal mm namespace or operation does not belong anywhere in core MM infrastructure - it should never get used anywhere other than the VFS/filesystem layers that implement the fallocate() syscall or use it directly. Cheers, Dave.
On Fri, Mar 11, 2022 at 10:08:22AM +1100, Dave Chinner wrote: > On Thu, Mar 10, 2022 at 10:09:01PM +0800, Chao Peng wrote: > > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > > > It maintains a memfile_notifier list in shmem_inode_info structure and > > implements memfile_pfn_ops callbacks defined by memfile_notifier. It > > then exposes them to memfile_notifier via > > shmem_get_memfile_notifier_info. > > > > We use SGP_NOALLOC in shmem_get_lock_pfn since the pages should be > > allocated by userspace for private memory. If there is no pages > > allocated at the offset then error should be returned so KVM knows that > > the memory is not private memory. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > > --- > > include/linux/shmem_fs.h | 4 +++ > > mm/shmem.c | 76 ++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 80 insertions(+) > > > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > > index 2dde843f28ef..7bb16f2d2825 100644 > > --- a/include/linux/shmem_fs.h > > +++ b/include/linux/shmem_fs.h > > @@ -9,6 +9,7 @@ > > #include <linux/percpu_counter.h> > > #include <linux/xattr.h> > > #include <linux/fs_parser.h> > > +#include <linux/memfile_notifier.h> > > > > /* inode in-kernel data */ > > > > @@ -28,6 +29,9 @@ struct shmem_inode_info { > > struct simple_xattrs xattrs; /* list of xattrs */ > > atomic_t stop_eviction; /* hold when working on inode */ > > unsigned int xflags; /* shmem extended flags */ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct memfile_notifier_list memfile_notifiers; > > +#endif > > struct inode vfs_inode; > > }; > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 9b31a7056009..7b43e274c9a2 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > > return page ? page_folio(page) : NULL; > > } > > > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > > +#endif > > +} > > *notify_populate(), not fallocate. This is a notification that a > range has been populated, not that the fallocate() syscall was run > to populate the backing store of a file. > > i.e. fallocate is the name of a userspace filesystem API that can > be used to manipulate the backing store of a file in various ways. > It can both populate and punch away the backing store of a file, and > some operations that fallocate() can run will do both (e.g. > FALLOC_FL_ZERO_RANGE) and so could generate both > notify_invalidate() and a notify_populate() events. Yes, I fully agreed fallocate syscall has both populating and hole punching semantics so notify_fallocate can be misleading since we actually mean populate here. > > Hence "fallocate" as an internal mm namespace or operation does not > belong anywhere in core MM infrastructure - it should never get used > anywhere other than the VFS/filesystem layers that implement the > fallocate() syscall or use it directly. Will use your suggestion through the series where applied. Thanks for your suggestion. Chao > > Cheers, > > Dave. > > -- > Dave Chinner > david@fromorbit.com
On Thu, Mar 10, 2022 at 10:09:01PM +0800, Chao Peng wrote: > diff --git a/mm/shmem.c b/mm/shmem.c > index 9b31a7056009..7b43e274c9a2 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > return page ? page_folio(page) : NULL; > } > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > +{ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct shmem_inode_info *info = SHMEM_I(inode); > + > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > +#endif All these #ifdefs look ugly. Could you provide dummy memfile_* for !MEMFILE_NOTIFIER case?
On Mon, Apr 11, 2022 at 06:26:47PM +0300, Kirill A. Shutemov wrote: > On Thu, Mar 10, 2022 at 10:09:01PM +0800, Chao Peng wrote: > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 9b31a7056009..7b43e274c9a2 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > > return page ? page_folio(page) : NULL; > > } > > > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > > +#endif > > All these #ifdefs look ugly. Could you provide dummy memfile_* for > !MEMFILE_NOTIFIER case? Sure. Chao > > -- > Kirill A. Shutemov
On Thu, Mar 10, 2022 at 6:10 AM Chao Peng <chao.p.peng@linux.intel.com> wrote: > > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > It maintains a memfile_notifier list in shmem_inode_info structure and > implements memfile_pfn_ops callbacks defined by memfile_notifier. It > then exposes them to memfile_notifier via > shmem_get_memfile_notifier_info. > > We use SGP_NOALLOC in shmem_get_lock_pfn since the pages should be > allocated by userspace for private memory. If there is no pages > allocated at the offset then error should be returned so KVM knows that > the memory is not private memory. > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > --- > include/linux/shmem_fs.h | 4 +++ > mm/shmem.c | 76 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 80 insertions(+) > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > index 2dde843f28ef..7bb16f2d2825 100644 > --- a/include/linux/shmem_fs.h > +++ b/include/linux/shmem_fs.h > @@ -9,6 +9,7 @@ > #include <linux/percpu_counter.h> > #include <linux/xattr.h> > #include <linux/fs_parser.h> > +#include <linux/memfile_notifier.h> > > /* inode in-kernel data */ > > @@ -28,6 +29,9 @@ struct shmem_inode_info { > struct simple_xattrs xattrs; /* list of xattrs */ > atomic_t stop_eviction; /* hold when working on inode */ > unsigned int xflags; /* shmem extended flags */ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct memfile_notifier_list memfile_notifiers; > +#endif > struct inode vfs_inode; > }; > > diff --git a/mm/shmem.c b/mm/shmem.c > index 9b31a7056009..7b43e274c9a2 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > return page ? page_folio(page) : NULL; > } > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > +{ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct shmem_inode_info *info = SHMEM_I(inode); > + > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > +#endif > +} > + > +static void notify_invalidate_page(struct inode *inode, struct folio *folio, > + pgoff_t start, pgoff_t end) > +{ > +#ifdef CONFIG_MEMFILE_NOTIFIER > + struct shmem_inode_info *info = SHMEM_I(inode); > + > + start = max(start, folio->index); > + end = min(end, folio->index + folio_nr_pages(folio)); > + > + memfile_notifier_invalidate(&info->memfile_notifiers, start, end); > +#endif > +} > + > /* > * Remove range of pages and swap entries from page cache, and free them. > * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. > @@ -946,6 +968,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > } > index += folio_nr_pages(folio) - 1; > > + notify_invalidate_page(inode, folio, start, end); > + > if (!unfalloc || !folio_test_uptodate(folio)) > truncate_inode_folio(mapping, folio); > folio_unlock(folio); > @@ -1019,6 +1043,9 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > index--; > break; > } > + > + notify_invalidate_page(inode, folio, start, end); > + Should this be done in batches or done once for all of range [start, end)? > VM_BUG_ON_FOLIO(folio_test_writeback(folio), > folio); > truncate_inode_folio(mapping, folio); > @@ -2279,6 +2306,9 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > info->flags = flags & VM_NORESERVE; > INIT_LIST_HEAD(&info->shrinklist); > INIT_LIST_HEAD(&info->swaplist); > +#ifdef CONFIG_MEMFILE_NOTIFIER > + memfile_notifier_list_init(&info->memfile_notifiers); > +#endif > simple_xattrs_init(&info->xattrs); > cache_no_acl(inode); > mapping_set_large_folios(inode->i_mapping); > @@ -2802,6 +2832,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, > if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) > i_size_write(inode, offset + len); > inode->i_ctime = current_time(inode); > + notify_fallocate(inode, start, end); > undone: > spin_lock(&inode->i_lock); > inode->i_private = NULL; > @@ -3909,6 +3940,47 @@ static struct file_system_type shmem_fs_type = { > .fs_flags = FS_USERNS_MOUNT, > }; > > +#ifdef CONFIG_MEMFILE_NOTIFIER > +static long shmem_get_lock_pfn(struct inode *inode, pgoff_t offset, int *order) > +{ > + struct page *page; > + int ret; > + > + ret = shmem_getpage(inode, offset, &page, SGP_NOALLOC); > + if (ret) > + return ret; > + > + *order = thp_order(compound_head(page)); > + > + return page_to_pfn(page); > +} > + > +static void shmem_put_unlock_pfn(unsigned long pfn) > +{ > + struct page *page = pfn_to_page(pfn); > + > + VM_BUG_ON_PAGE(!PageLocked(page), page); > + > + set_page_dirty(page); > + unlock_page(page); > + put_page(page); > +} > + > +static struct memfile_notifier_list* shmem_get_notifier_list(struct inode *inode) > +{ > + if (!shmem_mapping(inode->i_mapping)) > + return NULL; > + > + return &SHMEM_I(inode)->memfile_notifiers; > +} > + > +static struct memfile_backing_store shmem_backing_store = { > + .pfn_ops.get_lock_pfn = shmem_get_lock_pfn, > + .pfn_ops.put_unlock_pfn = shmem_put_unlock_pfn, > + .get_notifier_list = shmem_get_notifier_list, > +}; > +#endif /* CONFIG_MEMFILE_NOTIFIER */ > + > int __init shmem_init(void) > { > int error; > @@ -3934,6 +4006,10 @@ int __init shmem_init(void) > else > shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */ > #endif > + > +#ifdef CONFIG_MEMFILE_NOTIFIER > + memfile_register_backing_store(&shmem_backing_store); > +#endif > return 0; > > out1: > -- > 2.17.1 >
On Tue, Apr 19, 2022 at 03:40:09PM -0700, Vishal Annapurve wrote: > On Thu, Mar 10, 2022 at 6:10 AM Chao Peng <chao.p.peng@linux.intel.com> wrote: > > > > From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > > > > It maintains a memfile_notifier list in shmem_inode_info structure and > > implements memfile_pfn_ops callbacks defined by memfile_notifier. It > > then exposes them to memfile_notifier via > > shmem_get_memfile_notifier_info. > > > > We use SGP_NOALLOC in shmem_get_lock_pfn since the pages should be > > allocated by userspace for private memory. If there is no pages > > allocated at the offset then error should be returned so KVM knows that > > the memory is not private memory. > > > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> > > Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com> > > --- > > include/linux/shmem_fs.h | 4 +++ > > mm/shmem.c | 76 ++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 80 insertions(+) > > > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > > index 2dde843f28ef..7bb16f2d2825 100644 > > --- a/include/linux/shmem_fs.h > > +++ b/include/linux/shmem_fs.h > > @@ -9,6 +9,7 @@ > > #include <linux/percpu_counter.h> > > #include <linux/xattr.h> > > #include <linux/fs_parser.h> > > +#include <linux/memfile_notifier.h> > > > > /* inode in-kernel data */ > > > > @@ -28,6 +29,9 @@ struct shmem_inode_info { > > struct simple_xattrs xattrs; /* list of xattrs */ > > atomic_t stop_eviction; /* hold when working on inode */ > > unsigned int xflags; /* shmem extended flags */ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct memfile_notifier_list memfile_notifiers; > > +#endif > > struct inode vfs_inode; > > }; > > > > diff --git a/mm/shmem.c b/mm/shmem.c > > index 9b31a7056009..7b43e274c9a2 100644 > > --- a/mm/shmem.c > > +++ b/mm/shmem.c > > @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) > > return page ? page_folio(page) : NULL; > > } > > > > +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); > > +#endif > > +} > > + > > +static void notify_invalidate_page(struct inode *inode, struct folio *folio, > > + pgoff_t start, pgoff_t end) > > +{ > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + struct shmem_inode_info *info = SHMEM_I(inode); > > + > > + start = max(start, folio->index); > > + end = min(end, folio->index + folio_nr_pages(folio)); > > + > > + memfile_notifier_invalidate(&info->memfile_notifiers, start, end); > > +#endif > > +} > > + > > /* > > * Remove range of pages and swap entries from page cache, and free them. > > * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. > > @@ -946,6 +968,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > > } > > index += folio_nr_pages(folio) - 1; > > > > + notify_invalidate_page(inode, folio, start, end); > > + > > if (!unfalloc || !folio_test_uptodate(folio)) > > truncate_inode_folio(mapping, folio); > > folio_unlock(folio); > > @@ -1019,6 +1043,9 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, > > index--; > > break; > > } > > + > > + notify_invalidate_page(inode, folio, start, end); > > + > > Should this be done in batches or done once for all of range [start, end)? Batching is definitely prefered. Will look at that. Thanks, Chao > > > VM_BUG_ON_FOLIO(folio_test_writeback(folio), > > folio); > > truncate_inode_folio(mapping, folio); > > @@ -2279,6 +2306,9 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode > > info->flags = flags & VM_NORESERVE; > > INIT_LIST_HEAD(&info->shrinklist); > > INIT_LIST_HEAD(&info->swaplist); > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + memfile_notifier_list_init(&info->memfile_notifiers); > > +#endif > > simple_xattrs_init(&info->xattrs); > > cache_no_acl(inode); > > mapping_set_large_folios(inode->i_mapping); > > @@ -2802,6 +2832,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, > > if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) > > i_size_write(inode, offset + len); > > inode->i_ctime = current_time(inode); > > + notify_fallocate(inode, start, end); > > undone: > > spin_lock(&inode->i_lock); > > inode->i_private = NULL; > > @@ -3909,6 +3940,47 @@ static struct file_system_type shmem_fs_type = { > > .fs_flags = FS_USERNS_MOUNT, > > }; > > > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > +static long shmem_get_lock_pfn(struct inode *inode, pgoff_t offset, int *order) > > +{ > > + struct page *page; > > + int ret; > > + > > + ret = shmem_getpage(inode, offset, &page, SGP_NOALLOC); > > + if (ret) > > + return ret; > > + > > + *order = thp_order(compound_head(page)); > > + > > + return page_to_pfn(page); > > +} > > + > > +static void shmem_put_unlock_pfn(unsigned long pfn) > > +{ > > + struct page *page = pfn_to_page(pfn); > > + > > + VM_BUG_ON_PAGE(!PageLocked(page), page); > > + > > + set_page_dirty(page); > > + unlock_page(page); > > + put_page(page); > > +} > > + > > +static struct memfile_notifier_list* shmem_get_notifier_list(struct inode *inode) > > +{ > > + if (!shmem_mapping(inode->i_mapping)) > > + return NULL; > > + > > + return &SHMEM_I(inode)->memfile_notifiers; > > +} > > + > > +static struct memfile_backing_store shmem_backing_store = { > > + .pfn_ops.get_lock_pfn = shmem_get_lock_pfn, > > + .pfn_ops.put_unlock_pfn = shmem_put_unlock_pfn, > > + .get_notifier_list = shmem_get_notifier_list, > > +}; > > +#endif /* CONFIG_MEMFILE_NOTIFIER */ > > + > > int __init shmem_init(void) > > { > > int error; > > @@ -3934,6 +4006,10 @@ int __init shmem_init(void) > > else > > shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */ > > #endif > > + > > +#ifdef CONFIG_MEMFILE_NOTIFIER > > + memfile_register_backing_store(&shmem_backing_store); > > +#endif > > return 0; > > > > out1: > > -- > > 2.17.1 > >
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 2dde843f28ef..7bb16f2d2825 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -9,6 +9,7 @@ #include <linux/percpu_counter.h> #include <linux/xattr.h> #include <linux/fs_parser.h> +#include <linux/memfile_notifier.h> /* inode in-kernel data */ @@ -28,6 +29,9 @@ struct shmem_inode_info { struct simple_xattrs xattrs; /* list of xattrs */ atomic_t stop_eviction; /* hold when working on inode */ unsigned int xflags; /* shmem extended flags */ +#ifdef CONFIG_MEMFILE_NOTIFIER + struct memfile_notifier_list memfile_notifiers; +#endif struct inode vfs_inode; }; diff --git a/mm/shmem.c b/mm/shmem.c index 9b31a7056009..7b43e274c9a2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -903,6 +903,28 @@ static struct folio *shmem_get_partial_folio(struct inode *inode, pgoff_t index) return page ? page_folio(page) : NULL; } +static void notify_fallocate(struct inode *inode, pgoff_t start, pgoff_t end) +{ +#ifdef CONFIG_MEMFILE_NOTIFIER + struct shmem_inode_info *info = SHMEM_I(inode); + + memfile_notifier_fallocate(&info->memfile_notifiers, start, end); +#endif +} + +static void notify_invalidate_page(struct inode *inode, struct folio *folio, + pgoff_t start, pgoff_t end) +{ +#ifdef CONFIG_MEMFILE_NOTIFIER + struct shmem_inode_info *info = SHMEM_I(inode); + + start = max(start, folio->index); + end = min(end, folio->index + folio_nr_pages(folio)); + + memfile_notifier_invalidate(&info->memfile_notifiers, start, end); +#endif +} + /* * Remove range of pages and swap entries from page cache, and free them. * If !unfalloc, truncate or punch hole; if unfalloc, undo failed fallocate. @@ -946,6 +968,8 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, } index += folio_nr_pages(folio) - 1; + notify_invalidate_page(inode, folio, start, end); + if (!unfalloc || !folio_test_uptodate(folio)) truncate_inode_folio(mapping, folio); folio_unlock(folio); @@ -1019,6 +1043,9 @@ static void shmem_undo_range(struct inode *inode, loff_t lstart, loff_t lend, index--; break; } + + notify_invalidate_page(inode, folio, start, end); + VM_BUG_ON_FOLIO(folio_test_writeback(folio), folio); truncate_inode_folio(mapping, folio); @@ -2279,6 +2306,9 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode info->flags = flags & VM_NORESERVE; INIT_LIST_HEAD(&info->shrinklist); INIT_LIST_HEAD(&info->swaplist); +#ifdef CONFIG_MEMFILE_NOTIFIER + memfile_notifier_list_init(&info->memfile_notifiers); +#endif simple_xattrs_init(&info->xattrs); cache_no_acl(inode); mapping_set_large_folios(inode->i_mapping); @@ -2802,6 +2832,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset, if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) i_size_write(inode, offset + len); inode->i_ctime = current_time(inode); + notify_fallocate(inode, start, end); undone: spin_lock(&inode->i_lock); inode->i_private = NULL; @@ -3909,6 +3940,47 @@ static struct file_system_type shmem_fs_type = { .fs_flags = FS_USERNS_MOUNT, }; +#ifdef CONFIG_MEMFILE_NOTIFIER +static long shmem_get_lock_pfn(struct inode *inode, pgoff_t offset, int *order) +{ + struct page *page; + int ret; + + ret = shmem_getpage(inode, offset, &page, SGP_NOALLOC); + if (ret) + return ret; + + *order = thp_order(compound_head(page)); + + return page_to_pfn(page); +} + +static void shmem_put_unlock_pfn(unsigned long pfn) +{ + struct page *page = pfn_to_page(pfn); + + VM_BUG_ON_PAGE(!PageLocked(page), page); + + set_page_dirty(page); + unlock_page(page); + put_page(page); +} + +static struct memfile_notifier_list* shmem_get_notifier_list(struct inode *inode) +{ + if (!shmem_mapping(inode->i_mapping)) + return NULL; + + return &SHMEM_I(inode)->memfile_notifiers; +} + +static struct memfile_backing_store shmem_backing_store = { + .pfn_ops.get_lock_pfn = shmem_get_lock_pfn, + .pfn_ops.put_unlock_pfn = shmem_put_unlock_pfn, + .get_notifier_list = shmem_get_notifier_list, +}; +#endif /* CONFIG_MEMFILE_NOTIFIER */ + int __init shmem_init(void) { int error; @@ -3934,6 +4006,10 @@ int __init shmem_init(void) else shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */ #endif + +#ifdef CONFIG_MEMFILE_NOTIFIER + memfile_register_backing_store(&shmem_backing_store); +#endif return 0; out1: