diff options
Diffstat (limited to 'fs/dax.c')
| -rw-r--r-- | fs/dax.c | 20 |
1 files changed, 19 insertions, 1 deletions
@@ -29,6 +29,11 @@ #include <linux/uio.h> #include <linux/vmstat.h> +/* + * dax_clear_blocks() is called from within transaction context from XFS, + * and hence this means the stack from this point must follow GFP_NOFS + * semantics for all operations. + */ int dax_clear_blocks(struct inode *inode, sector_t block, long size) { struct block_device *bdev = inode->i_sb->s_bdev; @@ -169,8 +174,10 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, else len = iov_iter_zero(max - pos, iter); - if (!len) + if (!len) { + retval = -EFAULT; break; + } pos += len; addr += len; @@ -534,6 +541,10 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, unsigned long pfn; int result = 0; + /* dax pmd mappings are broken wrt gup and fork */ + if (!IS_ENABLED(CONFIG_FS_DAX_PMD)) + return VM_FAULT_FALLBACK; + /* Fall back to PTEs if we're going to COW */ if (write && !(vma->vm_flags & VM_SHARED)) return VM_FAULT_FALLBACK; @@ -622,6 +633,13 @@ int __dax_pmd_fault(struct vm_area_struct *vma, unsigned long address, if ((length < PMD_SIZE) || (pfn & PG_PMD_COLOUR)) goto fallback; + /* + * TODO: teach vmf_insert_pfn_pmd() to support + * 'pte_special' for pmds + */ + if (pfn_valid(pfn)) + goto fallback; + if (buffer_unwritten(&bh) || buffer_new(&bh)) { int i; for (i = 0; i < PTRS_PER_PMD; i++) |