orangefs: implement vm_ops->fault (a5135eea) · Commits · 戴 / test

Must retrieve size before running filemap_fault so the kernel has an up-to-date size. This should have been caught by xfstests generic/246, but it was masked by orangefs_new_inode, which set i_size to PAGE_SIZE. When nothing caused a getattr prior to a pagefault, i_size was still PAGE_SIZE. Since xfstests only read 10 bytes, it did not catch this bug. When orangefs_new_inode was modified to perform a getattr instead, i_size was set to zero, as it was a newly created file. Then orangefs_file_write_iter did NOT set i_size. Instead it invalidated the attribute cache, which should have caused the next caller to retrieve i_size. But the fault handler did not know it was supposed to retrieve i_size. So during xfstests, i_size was still zero, and filemap_fault returned VM_FAULT_SIGBUS. Fixes xfstests generic/452. Signed-off-by:

Martin Brandenburg <martin@omnibond.com> Signed-off-by:

Mike Marshall <hubcap@omnibond.com>

fs/orangefs/file.c

+28 −2

Original line number	Diff line number	Diff line
		@@ -528,6 +528,28 @@ static long orangefs_ioctl(struct file *file, unsigned int cmd, unsigned long ar
		return ret;
		}

		static int orangefs_fault(struct vm_fault *vmf)
		{
		struct file *file = vmf->vma->vm_file;
		int rc;
		rc = orangefs_inode_getattr(file->f_mapping->host, 0, 1,
		STATX_SIZE);
		if (rc == -ESTALE)
		rc = -EIO;
		if (rc) {
		gossip_err("%s: orangefs_inode_getattr failed, "
		"rc:%d:.\n", __func__, rc);
		return rc;
		}
		return filemap_fault(vmf);
		}

		const struct vm_operations_struct orangefs_file_vm_ops = {
		.fault = orangefs_fault,
		.map_pages = filemap_map_pages,
		.page_mkwrite = filemap_page_mkwrite,
		};

		/*
		* Memory map a region of a file.
		*/
		@@ -539,12 +561,16 @@ static int orangefs_file_mmap(struct file file, struct vm_area_struct vma)
		(char *)file->f_path.dentry->d_name.name :
		(char *)"Unknown"));

		if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_MAYWRITE))
		return -EINVAL;

		/* set the sequential readahead hint */
		vma->vm_flags \|= VM_SEQ_READ;
		vma->vm_flags &= ~VM_RAND_READ;

		/* Use readonly mmap since we cannot support writable maps. */
		return generic_file_readonly_mmap(file, vma);
		file_accessed(file);
		vma->vm_ops = &orangefs_file_vm_ops;
		return 0;
		}

		#define mapping_nrpages(idata) ((idata)->nrpages)

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