From: Shiyang Ruan <ruansy.fnst@cn.fujitsu.com>
To: <linux-xfs@vger.kernel.org>, <linux-nvdimm@lists.01.org>,
<darrick.wong@oracle.com>
Cc: <linux-kernel@vger.kernel.org>, <rgoldwyn@suse.de>,
<gujx@cn.fujitsu.com>, <david@fromorbit.com>,
<qi.fuli@fujitsu.com>, <caoj.fnst@cn.fujitsu.com>,
<ruansy.fnst@cn.fujitsu.com>
Subject: [RFC PATCH 2/7] dax: copy data before write.
Date: Wed, 31 Jul 2019 19:49:30 +0800 [thread overview]
Message-ID: <20190731114935.11030-3-ruansy.fnst@cn.fujitsu.com> (raw)
In-Reply-To: <20190731114935.11030-1-ruansy.fnst@cn.fujitsu.com>
Add dax_copy_edges() into each dax actor functions to perform COW in the
case of IOMAP_COW type is set.
Signed-off-by: Shiyang Ruan <ruansy.fnst@cn.fujitsu.com>
---
fs/dax.c | 39 +++++++++++++++++++++++++++++++++------
1 file changed, 33 insertions(+), 6 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 450baafe2ea4..084cc21d47a4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1098,11 +1098,12 @@ EXPORT_SYMBOL_GPL(__dax_zero_page_range);
* offset/offset+length are not page aligned.
*/
static int dax_copy_edges(struct inode *inode, loff_t pos, loff_t length,
- struct iomap *srcmap, void *daddr)
+ struct iomap *srcmap, void *daddr, bool pmd)
{
- unsigned offset = pos & (PAGE_SIZE - 1);
+ size_t page_size = pmd ? PMD_SIZE : PAGE_SIZE;
+ unsigned offset = pos & (page_size - 1);
loff_t end = pos + length;
- loff_t pg_end = round_up(end, PAGE_SIZE);
+ loff_t pg_end = round_up(end, page_size);
void *saddr = 0;
int ret = 0;
@@ -1153,7 +1154,8 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
return iov_iter_zero(min(length, end - pos), iter);
}
- if (WARN_ON_ONCE(iomap->type != IOMAP_MAPPED))
+ if (WARN_ON_ONCE(iomap->type != IOMAP_MAPPED &&
+ iomap->type != IOMAP_COW))
return -EIO;
/*
@@ -1192,6 +1194,13 @@ dax_iomap_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
break;
}
+ if (iomap->type == IOMAP_COW) {
+ ret = dax_copy_edges(inode, pos, length, srcmap, kaddr,
+ false);
+ if (ret)
+ break;
+ }
+
map_len = PFN_PHYS(map_len);
kaddr += offset;
map_len -= offset;
@@ -1300,6 +1309,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
vm_fault_t ret = 0;
void *entry;
pfn_t pfn;
+ void *kaddr;
trace_dax_pte_fault(inode, vmf, ret);
/*
@@ -1380,19 +1390,27 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
sync = dax_fault_is_synchronous(flags, vma, &iomap);
switch (iomap.type) {
+ case IOMAP_COW:
case IOMAP_MAPPED:
if (iomap.flags & IOMAP_F_NEW) {
count_vm_event(PGMAJFAULT);
count_memcg_event_mm(vma->vm_mm, PGMAJFAULT);
major = VM_FAULT_MAJOR;
}
- error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn, NULL);
+ error = dax_iomap_pfn(&iomap, pos, PAGE_SIZE, &pfn, &kaddr);
if (error < 0)
goto error_finish_iomap;
entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn,
0, write && !sync);
+ if (iomap.type == IOMAP_COW) {
+ error = dax_copy_edges(inode, pos, PAGE_SIZE, &srcmap,
+ kaddr, false);
+ if (error)
+ goto error_finish_iomap;
+ }
+
/*
* If we are doing synchronous page fault and inode needs fsync,
* we can insert PTE into page tables only after that happens.
@@ -1523,6 +1541,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
loff_t pos;
int error;
pfn_t pfn;
+ void *kaddr;
/*
* Check whether offset isn't beyond end of file now. Caller is
@@ -1602,14 +1621,22 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
sync = dax_fault_is_synchronous(iomap_flags, vma, &iomap);
switch (iomap.type) {
+ case IOMAP_COW:
case IOMAP_MAPPED:
- error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn, NULL);
+ error = dax_iomap_pfn(&iomap, pos, PMD_SIZE, &pfn, &kaddr);
if (error < 0)
goto finish_iomap;
entry = dax_insert_entry(&xas, mapping, vmf, entry, pfn,
DAX_PMD, write && !sync);
+ if (iomap.type == IOMAP_COW) {
+ error = dax_copy_edges(inode, pos, PMD_SIZE, &srcmap,
+ kaddr, true);
+ if (error)
+ goto unlock_entry;
+ }
+
/*
* If we are doing synchronous page fault and inode needs fsync,
* we can insert PMD into page tables only after that happens.
--
2.17.0
next prev parent reply other threads:[~2019-07-31 11:49 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-31 11:49 [RFC PATCH 0/7] xfs: add reflink & dedupe support for fsdax Shiyang Ruan
2019-07-31 11:49 ` [RFC PATCH 1/7] dax: Introduce dax_copy_edges() for COW Shiyang Ruan
2019-07-31 11:49 ` Shiyang Ruan [this message]
2019-07-31 11:49 ` [RFC PATCH 3/7] dax: replace mmap entry in case of CoW Shiyang Ruan
2019-07-31 11:49 ` [RFC PATCH 4/7] fs: dedup file range to use a compare function Shiyang Ruan
2019-07-31 11:49 ` [RFC PATCH 5/7] dax: memcpy before zeroing range Shiyang Ruan
2019-07-31 11:49 ` [RFC PATCH 6/7] xfs: Add COW handle for fsdax Shiyang Ruan
2019-07-31 11:49 ` [RFC PATCH 7/7] xfs: Add dedupe support " Shiyang Ruan
2019-07-31 20:33 ` [RFC PATCH 0/7] xfs: add reflink & " Goldwyn Rodrigues
2019-08-01 1:37 ` Shiyang Ruan
2019-08-05 0:21 ` Dave Chinner
2019-10-09 6:31 ` Christoph Hellwig
2019-10-09 17:11 ` Darrick J. Wong
2019-10-10 7:30 ` Dave Chinner
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