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From:   Christoph Hellwig <hch@lst.de>
To:     Dan Williams <dan.j.williams@intel.com>
Cc:     Mike Snitzer <snitzer@redhat.com>, Ira Weiny <ira.weiny@intel.com>,
        dm-devel@redhat.com, linux-xfs@vger.kernel.org,
        nvdimm@lists.linux.dev, linux-s390@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org,
        linux-ext4@vger.kernel.org,
        virtualization@lists.linux-foundation.org
Subject: [PATCH 22/29] iomap: add a IOMAP_DAX flag
Date:   Tue,  9 Nov 2021 09:33:02 +0100
Message-Id: <20211109083309.584081-23-hch@lst.de>
In-Reply-To: <20211109083309.584081-1-hch@lst.de>
References: <20211109083309.584081-1-hch@lst.de>
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Add a flag so that the file system can easily detect DAX operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/dax.c              | 7 ++++---
 include/linux/iomap.h | 1 +
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index 5b52b878124ac..0bd6cdcbacfc4 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -1180,7 +1180,7 @@ int dax_zero_range(struct inode *inode, loff_t pos, loff_t len, bool *did_zero,
 		.inode		= inode,
 		.pos		= pos,
 		.len		= len,
-		.flags		= IOMAP_ZERO,
+		.flags		= IOMAP_DAX | IOMAP_ZERO,
 	};
 	int ret;
 
@@ -1308,6 +1308,7 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter,
 		.inode		= iocb->ki_filp->f_mapping->host,
 		.pos		= iocb->ki_pos,
 		.len		= iov_iter_count(iter),
+		.flags		= IOMAP_DAX,
 	};
 	loff_t done = 0;
 	int ret;
@@ -1461,7 +1462,7 @@ static vm_fault_t dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp,
 		.inode		= mapping->host,
 		.pos		= (loff_t)vmf->pgoff << PAGE_SHIFT,
 		.len		= PAGE_SIZE,
-		.flags		= IOMAP_FAULT,
+		.flags		= IOMAP_DAX | IOMAP_FAULT,
 	};
 	vm_fault_t ret = 0;
 	void *entry;
@@ -1570,7 +1571,7 @@ static vm_fault_t dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp,
 	struct iomap_iter iter = {
 		.inode		= mapping->host,
 		.len		= PMD_SIZE,
-		.flags		= IOMAP_FAULT,
+		.flags		= IOMAP_DAX | IOMAP_FAULT,
 	};
 	vm_fault_t ret = VM_FAULT_FALLBACK;
 	pgoff_t max_pgoff;
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 6d1b08d0ae930..146a7e3e3ea11 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -141,6 +141,7 @@ struct iomap_page_ops {
 #define IOMAP_NOWAIT		(1 << 5) /* do not block */
 #define IOMAP_OVERWRITE_ONLY	(1 << 6) /* only pure overwrites allowed */
 #define IOMAP_UNSHARE		(1 << 7) /* unshare_file_range */
+#define IOMAP_DAX		(1 << 8) /* DAX mapping */
 
 struct iomap_ops {
 	/*
-- 
2.30.2