From: Shiyang Ruan <ruansy.fnst@fujitsu.com> To: <linux-kernel@vger.kernel.org>, <linux-xfs@vger.kernel.org>, <linux-nvdimm@lists.01.org>, <linux-fsdevel@vger.kernel.org> Cc: <darrick.wong@oracle.com>, <dan.j.williams@intel.com>, <willy@infradead.org>, <viro@zeniv.linux.org.uk>, <david@fromorbit.com>, <hch@lst.de>, <rgoldwyn@suse.de>, Goldwyn Rodrigues <rgoldwyn@suse.com>, Ritesh Harjani <riteshh@linux.ibm.com> Subject: [PATCH v5 2/7] fsdax: Replace mmap entry in case of CoW Date: Tue, 11 May 2021 11:09:28 +0800 [thread overview] Message-ID: <20210511030933.3080921-3-ruansy.fnst@fujitsu.com> (raw) In-Reply-To: <20210511030933.3080921-1-ruansy.fnst@fujitsu.com> We replace the existing entry to the newly allocated one in case of CoW. Also, we mark the entry as PAGECACHE_TAG_TOWRITE so writeback marks this entry as writeprotected. This helps us snapshots so new write pagefaults after snapshots trigger a CoW. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> --- fs/dax.c | 39 ++++++++++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 11 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index f0249bb1d46a..ef0e564e7904 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -722,6 +722,10 @@ static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_d return 0; } +/* DAX Insert Flag: The state of the entry we insert */ +#define DAX_IF_DIRTY (1 << 0) +#define DAX_IF_COW (1 << 1) + /* * By this point grab_mapping_entry() has ensured that we have a locked entry * of the appropriate size so we don't have to worry about downgrading PMDs to @@ -729,16 +733,19 @@ static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_d * already in the tree, we will skip the insertion and just dirty the PMD as * appropriate. */ -static void *dax_insert_entry(struct xa_state *xas, - struct address_space *mapping, struct vm_fault *vmf, - void *entry, pfn_t pfn, unsigned long flags, bool dirty) +static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf, + void *entry, pfn_t pfn, unsigned long flags, + unsigned int insert_flags) { + struct address_space *mapping = vmf->vma->vm_file->f_mapping; void *new_entry = dax_make_entry(pfn, flags); + bool dirty = insert_flags & DAX_IF_DIRTY; + bool cow = insert_flags & DAX_IF_COW; if (dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); - if (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE)) { + if (cow || (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE))) { unsigned long index = xas->xa_index; /* we are replacing a zero page with block mapping */ if (dax_is_pmd_entry(entry)) @@ -750,7 +757,7 @@ static void *dax_insert_entry(struct xa_state *xas, xas_reset(xas); xas_lock_irq(xas); - if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { + if (cow || dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { void *old; dax_disassociate_entry(entry, mapping, false); @@ -774,6 +781,9 @@ static void *dax_insert_entry(struct xa_state *xas, if (dirty) xas_set_mark(xas, PAGECACHE_TAG_DIRTY); + if (cow) + xas_set_mark(xas, PAGECACHE_TAG_TOWRITE); + xas_unlock_irq(xas); return entry; } @@ -1109,8 +1119,7 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr)); vm_fault_t ret; - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, - DAX_ZERO_PAGE, false); + *entry = dax_insert_entry(xas, vmf, *entry, pfn, DAX_ZERO_PAGE, 0); ret = vmf_insert_mixed(vmf->vma, vaddr, pfn); trace_dax_load_hole(inode, vmf, ret); @@ -1137,8 +1146,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, goto fallback; pfn = page_to_pfn_t(zero_page); - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, - DAX_PMD | DAX_ZERO_PAGE, false); + *entry = dax_insert_entry(xas, vmf, *entry, pfn, + DAX_PMD | DAX_ZERO_PAGE, 0); if (arch_needs_pgtable_deposit()) { pgtable = pte_alloc_one(vma->vm_mm); @@ -1448,6 +1457,7 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, bool write = vmf->flags & FAULT_FLAG_WRITE; bool sync = dax_fault_is_synchronous(flags, vmf->vma, iomap); unsigned long entry_flags = pmd ? DAX_PMD : 0; + unsigned int insert_flags = 0; int err = 0; pfn_t pfn; void *kaddr; @@ -1470,8 +1480,15 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, if (err) return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, entry_flags, - write && !sync); + if (write) { + if (!sync) + insert_flags |= DAX_IF_DIRTY; + if (iomap->flags & IOMAP_F_SHARED) + insert_flags |= DAX_IF_COW; + } + + *entry = dax_insert_entry(xas, vmf, *entry, pfn, entry_flags, + insert_flags); if (write && srcmap->addr != IOMAP_HOLE && srcmap->addr != iomap->addr) { -- 2.31.1
WARNING: multiple messages have this Message-ID (diff)
From: Shiyang Ruan <ruansy.fnst@fujitsu.com> To: <linux-kernel@vger.kernel.org>, <linux-xfs@vger.kernel.org>, <linux-nvdimm@lists.01.org>, <linux-fsdevel@vger.kernel.org> Cc: darrick.wong@oracle.com, willy@infradead.org, viro@zeniv.linux.org.uk, david@fromorbit.com, hch@lst.de, rgoldwyn@suse.de, Goldwyn Rodrigues <rgoldwyn@suse.com> Subject: [PATCH v5 2/7] fsdax: Replace mmap entry in case of CoW Date: Tue, 11 May 2021 11:09:28 +0800 [thread overview] Message-ID: <20210511030933.3080921-3-ruansy.fnst@fujitsu.com> (raw) In-Reply-To: <20210511030933.3080921-1-ruansy.fnst@fujitsu.com> We replace the existing entry to the newly allocated one in case of CoW. Also, we mark the entry as PAGECACHE_TAG_TOWRITE so writeback marks this entry as writeprotected. This helps us snapshots so new write pagefaults after snapshots trigger a CoW. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> --- fs/dax.c | 39 ++++++++++++++++++++++++++++----------- 1 file changed, 28 insertions(+), 11 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index f0249bb1d46a..ef0e564e7904 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -722,6 +722,10 @@ static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_d return 0; } +/* DAX Insert Flag: The state of the entry we insert */ +#define DAX_IF_DIRTY (1 << 0) +#define DAX_IF_COW (1 << 1) + /* * By this point grab_mapping_entry() has ensured that we have a locked entry * of the appropriate size so we don't have to worry about downgrading PMDs to @@ -729,16 +733,19 @@ static int copy_cow_page_dax(struct block_device *bdev, struct dax_device *dax_d * already in the tree, we will skip the insertion and just dirty the PMD as * appropriate. */ -static void *dax_insert_entry(struct xa_state *xas, - struct address_space *mapping, struct vm_fault *vmf, - void *entry, pfn_t pfn, unsigned long flags, bool dirty) +static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf, + void *entry, pfn_t pfn, unsigned long flags, + unsigned int insert_flags) { + struct address_space *mapping = vmf->vma->vm_file->f_mapping; void *new_entry = dax_make_entry(pfn, flags); + bool dirty = insert_flags & DAX_IF_DIRTY; + bool cow = insert_flags & DAX_IF_COW; if (dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); - if (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE)) { + if (cow || (dax_is_zero_entry(entry) && !(flags & DAX_ZERO_PAGE))) { unsigned long index = xas->xa_index; /* we are replacing a zero page with block mapping */ if (dax_is_pmd_entry(entry)) @@ -750,7 +757,7 @@ static void *dax_insert_entry(struct xa_state *xas, xas_reset(xas); xas_lock_irq(xas); - if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { + if (cow || dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) { void *old; dax_disassociate_entry(entry, mapping, false); @@ -774,6 +781,9 @@ static void *dax_insert_entry(struct xa_state *xas, if (dirty) xas_set_mark(xas, PAGECACHE_TAG_DIRTY); + if (cow) + xas_set_mark(xas, PAGECACHE_TAG_TOWRITE); + xas_unlock_irq(xas); return entry; } @@ -1109,8 +1119,7 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr)); vm_fault_t ret; - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, - DAX_ZERO_PAGE, false); + *entry = dax_insert_entry(xas, vmf, *entry, pfn, DAX_ZERO_PAGE, 0); ret = vmf_insert_mixed(vmf->vma, vaddr, pfn); trace_dax_load_hole(inode, vmf, ret); @@ -1137,8 +1146,8 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf, goto fallback; pfn = page_to_pfn_t(zero_page); - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, - DAX_PMD | DAX_ZERO_PAGE, false); + *entry = dax_insert_entry(xas, vmf, *entry, pfn, + DAX_PMD | DAX_ZERO_PAGE, 0); if (arch_needs_pgtable_deposit()) { pgtable = pte_alloc_one(vma->vm_mm); @@ -1448,6 +1457,7 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, bool write = vmf->flags & FAULT_FLAG_WRITE; bool sync = dax_fault_is_synchronous(flags, vmf->vma, iomap); unsigned long entry_flags = pmd ? DAX_PMD : 0; + unsigned int insert_flags = 0; int err = 0; pfn_t pfn; void *kaddr; @@ -1470,8 +1480,15 @@ static vm_fault_t dax_fault_actor(struct vm_fault *vmf, pfn_t *pfnp, if (err) return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); - *entry = dax_insert_entry(xas, mapping, vmf, *entry, pfn, entry_flags, - write && !sync); + if (write) { + if (!sync) + insert_flags |= DAX_IF_DIRTY; + if (iomap->flags & IOMAP_F_SHARED) + insert_flags |= DAX_IF_COW; + } + + *entry = dax_insert_entry(xas, vmf, *entry, pfn, entry_flags, + insert_flags); if (write && srcmap->addr != IOMAP_HOLE && srcmap->addr != iomap->addr) { -- 2.31.1 _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
next prev parent reply other threads:[~2021-05-11 3:10 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-11 3:09 [PATCH v5 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-11 3:09 ` [PATCH v5 1/7] fsdax: Introduce dax_iomap_cow_copy() Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-12 1:08 ` Darrick J. Wong 2021-05-12 1:08 ` Darrick J. Wong 2021-05-13 7:57 ` ruansy.fnst 2021-05-13 7:57 ` ruansy.fnst 2021-05-13 15:02 ` Darrick J. Wong 2021-05-13 15:02 ` Darrick J. Wong 2021-05-11 3:09 ` Shiyang Ruan [this message] 2021-05-11 3:09 ` [PATCH v5 2/7] fsdax: Replace mmap entry in case of CoW Shiyang Ruan 2021-05-12 1:09 ` Darrick J. Wong 2021-05-12 1:09 ` Darrick J. Wong 2021-05-11 3:09 ` [PATCH v5 3/7] fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-12 1:17 ` Darrick J. Wong 2021-05-12 1:17 ` Darrick J. Wong 2021-05-12 1:37 ` ruansy.fnst 2021-05-12 1:37 ` ruansy.fnst 2021-05-25 22:17 ` Darrick J. Wong 2021-05-12 2:27 ` Mika Penttilä 2021-05-12 2:27 ` Mika Penttilä 2021-05-13 7:48 ` ruansy.fnst 2021-05-13 7:48 ` ruansy.fnst 2021-05-11 3:09 ` [PATCH v5 4/7] iomap: Introduce iomap_apply2() for operations on two files Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-11 3:09 ` [PATCH v5 5/7] fsdax: Dedup file range to use a compare function Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-12 1:23 ` Darrick J. Wong 2021-05-12 1:23 ` Darrick J. Wong 2021-05-14 8:35 ` ruansy.fnst 2021-05-14 8:35 ` ruansy.fnst 2021-05-14 16:03 ` Darrick J. Wong 2021-05-14 16:03 ` Darrick J. Wong 2021-05-11 3:09 ` [PATCH v5 6/7] fs/xfs: Handle CoW for fsdax write() path Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-12 1:30 ` Darrick J. Wong 2021-05-12 1:30 ` Darrick J. Wong 2021-05-11 3:09 ` [PATCH v5 7/7] fs/xfs: Add dax dedupe support Shiyang Ruan 2021-05-11 3:09 ` Shiyang Ruan 2021-05-12 1:04 ` Darrick J. Wong 2021-05-12 1:04 ` Darrick J. Wong 2021-05-12 1:26 ` ruansy.fnst 2021-05-12 1:26 ` ruansy.fnst 2021-05-11 3:57 ` [PATCH v5 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax Darrick J. Wong 2021-05-11 3:57 ` Darrick J. Wong 2021-05-11 5:53 ` ruansy.fnst 2021-05-11 5:53 ` ruansy.fnst
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