From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
"Darrick J. Wong" <djwong@kernel.org>,
Jason Gunthorpe <jgg@nvidia.com>, Christoph Hellwig <hch@lst.de>,
John Hubbard <jhubbard@nvidia.com>,
linux-mm@kvack.org, nvdimm@lists.linux.dev,
linux-fsdevel@vger.kernel.org
Subject: [PATCH 04/13] fsdax: Update dax_insert_entry() calling convention to return an error
Date: Sat, 03 Sep 2022 19:16:23 -0700 [thread overview]
Message-ID: <166225778308.2351842.10359830461531484766.stgit@dwillia2-xfh.jf.intel.com> (raw)
In-Reply-To: <166225775968.2351842.11156458342486082012.stgit@dwillia2-xfh.jf.intel.com>
In preparation for teaching dax_insert_entry() to take live @pgmap
references, enable it to return errors. Given the observation that all
callers overwrite the passed in entry with the return value, just update
@entry in place and convert the return code to a vm_fault_t status.
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
fs/dax.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index aceb587bc27e..d2fb58a7449b 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -853,14 +853,15 @@ static bool dax_fault_is_cow(const struct iomap_iter *iter)
* 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 vm_fault *vmf,
- const struct iomap_iter *iter, void *entry, pfn_t pfn,
- unsigned long flags)
+static vm_fault_t dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf,
+ const struct iomap_iter *iter, void **pentry,
+ pfn_t pfn, unsigned long flags)
{
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
void *new_entry = dax_make_entry(pfn, flags);
bool dirty = !dax_fault_is_synchronous(iter, vmf->vma);
bool cow = dax_fault_is_cow(iter);
+ void *entry = *pentry;
if (dirty)
__mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
@@ -906,7 +907,8 @@ static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf,
xas_set_mark(xas, PAGECACHE_TAG_TOWRITE);
xas_unlock_irq(xas);
- return entry;
+ *pentry = entry;
+ return 0;
}
static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev,
@@ -1154,9 +1156,12 @@ static vm_fault_t dax_load_hole(struct xa_state *xas, struct vm_fault *vmf,
pfn_t pfn = pfn_to_pfn_t(my_zero_pfn(vaddr));
vm_fault_t ret;
- *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, DAX_ZERO_PAGE);
+ ret = dax_insert_entry(xas, vmf, iter, entry, pfn, DAX_ZERO_PAGE);
+ if (ret)
+ goto out;
ret = vmf_insert_mixed(vmf->vma, vaddr, pfn);
+out:
trace_dax_load_hole(inode, vmf, ret);
return ret;
}
@@ -1173,6 +1178,7 @@ static vm_fault_t dax_pmd_load_hole(struct xa_state *xas, struct vm_fault *vmf,
struct page *zero_page;
spinlock_t *ptl;
pmd_t pmd_entry;
+ vm_fault_t ret;
pfn_t pfn;
zero_page = mm_get_huge_zero_page(vmf->vma->vm_mm);
@@ -1181,8 +1187,10 @@ 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, vmf, iter, *entry, pfn,
- DAX_PMD | DAX_ZERO_PAGE);
+ ret = dax_insert_entry(xas, vmf, iter, entry, pfn,
+ DAX_PMD | DAX_ZERO_PAGE);
+ if (ret)
+ return ret;
if (arch_needs_pgtable_deposit()) {
pgtable = pte_alloc_one(vma->vm_mm);
@@ -1534,6 +1542,7 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf,
loff_t pos = (loff_t)xas->xa_index << PAGE_SHIFT;
bool write = iter->flags & IOMAP_WRITE;
unsigned long entry_flags = pmd ? DAX_PMD : 0;
+ vm_fault_t ret;
int err = 0;
pfn_t pfn;
void *kaddr;
@@ -1558,7 +1567,9 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf,
if (err)
return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err);
- *entry = dax_insert_entry(xas, vmf, iter, *entry, pfn, entry_flags);
+ ret = dax_insert_entry(xas, vmf, iter, entry, pfn, entry_flags);
+ if (ret)
+ return ret;
if (write &&
srcmap->type != IOMAP_HOLE && srcmap->addr != iomap->addr) {
next prev parent reply other threads:[~2022-09-04 2:16 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-04 2:16 [PATCH 00/13] Fix the DAX-gup mistake Dan Williams
2022-09-04 2:16 ` [PATCH 01/13] fsdax: Rename "busy page" to "pinned page" Dan Williams
2022-09-04 2:16 ` [PATCH 02/13] fsdax: Use page_maybe_dma_pinned() for DAX vs DMA collisions Dan Williams
2022-09-06 12:07 ` Jason Gunthorpe
2022-09-04 2:16 ` [PATCH 03/13] fsdax: Delete put_devmap_managed_page_refs() Dan Williams
2022-09-04 2:16 ` Dan Williams [this message]
2022-09-04 2:16 ` [PATCH 05/13] fsdax: Cleanup dax_associate_entry() Dan Williams
2022-09-04 2:16 ` [PATCH 06/13] fsdax: Rework dax_insert_entry() calling convention Dan Williams
2022-09-04 2:16 ` [PATCH 07/13] fsdax: Manage pgmap references at entry insertion and deletion Dan Williams
2022-09-06 12:30 ` Jason Gunthorpe
2022-09-04 2:16 ` [PATCH 08/13] devdax: Minor warning fixups Dan Williams
2022-09-04 2:16 ` [PATCH 09/13] devdax: Move address_space helpers to the DAX core Dan Williams
2022-09-04 2:16 ` [PATCH 10/13] dax: Prep dax_{associate, disassociate}_entry() for compound pages Dan Williams
2022-09-04 2:17 ` [PATCH 11/13] devdax: add PUD support to the DAX mapping infrastructure Dan Williams
2022-09-04 2:17 ` [PATCH 12/13] devdax: Use dax_insert_entry() + dax_delete_mapping_entry() Dan Williams
2022-09-04 2:17 ` [PATCH 13/13] mm/gup: Drop DAX pgmap accounting Dan Williams
2022-09-06 13:05 ` [PATCH 00/13] Fix the DAX-gup mistake Jason Gunthorpe
2022-09-06 17:23 ` Dan Williams
2022-09-06 17:29 ` Jason Gunthorpe
2022-09-06 18:37 ` Dan Williams
2022-09-06 18:49 ` Jason Gunthorpe
2022-09-06 19:41 ` Dan Williams
2022-09-07 0:54 ` Dan Williams
2022-09-07 12:58 ` Jason Gunthorpe
2022-09-07 17:10 ` Dan Williams
2022-09-07 18:43 ` Dan Williams
2022-09-07 19:30 ` Jason Gunthorpe
2022-09-07 20:45 ` Dan Williams
2022-09-08 18:49 ` Jason Gunthorpe
2022-09-08 19:27 ` Dan Williams
2022-09-09 11:53 ` Jason Gunthorpe
2022-09-09 17:52 ` Dan Williams
2022-09-09 18:11 ` Matthew Wilcox
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