Messages in this thread Patch in this message | | | From | Shiyang Ruan <> | Subject | [PATCH v11 01/07] fsdax: Output address in dax_iomap_pfn() and rename it | Date | Sun, 8 May 2022 22:36:14 +0800 |
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Add address output in dax_iomap_pfn() in order to perform a memcpy() in CoW case. Since this function both output address and pfn, rename it to dax_iomap_direct_access().
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> --- fs/dax.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c index 4d3dfc8bee33..d4f195aeaa12 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1025,8 +1025,8 @@ int dax_writeback_mapping_range(struct address_space *mapping, } EXPORT_SYMBOL_GPL(dax_writeback_mapping_range); -static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size, - pfn_t *pfnp) +static int dax_iomap_direct_access(const struct iomap *iomap, loff_t pos, + size_t size, void **kaddr, pfn_t *pfnp) { pgoff_t pgoff = dax_iomap_pgoff(iomap, pos); int id, rc; @@ -1034,11 +1034,13 @@ static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size, id = dax_read_lock(); length = dax_direct_access(iomap->dax_dev, pgoff, PHYS_PFN(size), - NULL, pfnp); + kaddr, pfnp); if (length < 0) { rc = length; goto out; } + if (!pfnp) + goto out_check_addr; rc = -EINVAL; if (PFN_PHYS(length) < size) goto out; @@ -1048,6 +1050,12 @@ static int dax_iomap_pfn(const struct iomap *iomap, loff_t pos, size_t size, if (length > 1 && !pfn_t_devmap(*pfnp)) goto out; rc = 0; + +out_check_addr: + if (!kaddr) + goto out; + if (!*kaddr) + rc = -EFAULT; out: dax_read_unlock(id); return rc; @@ -1444,7 +1452,7 @@ static vm_fault_t dax_fault_iter(struct vm_fault *vmf, return pmd ? VM_FAULT_FALLBACK : VM_FAULT_SIGBUS; } - err = dax_iomap_pfn(&iter->iomap, pos, size, &pfn); + err = dax_iomap_direct_access(&iter->iomap, pos, size, NULL, &pfn); if (err) return pmd ? VM_FAULT_FALLBACK : dax_fault_return(err); -- 2.35.1
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