Currently iomap_end() doesn't do anything for DAX page faults for both ext2 and XFS. ext2_iomap_end() just checks for a write underrun, and xfs_file_iomap_end() checks to see if it needs to finish a delayed allocation. However, in the future iomap_end() calls might be needed to make sure we have balanced allocations, locks, etc. So, add calls to iomap_end() with appropriate error handling to dax_iomap_fault().
Signed-off-by: Ross Zwisler <[email protected]> Suggested-by: Jan Kara <[email protected]> --- fs/dax.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 7689ab0..5e8febe 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1187,7 +1187,7 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, goto unlock_entry; if (WARN_ON_ONCE(iomap.offset + iomap.length < pos + PAGE_SIZE)) { error = -EIO; /* fs corruption? */ - goto unlock_entry; + goto finish_iomap; } sector = dax_iomap_sector(&iomap, pos); @@ -1209,7 +1209,14 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, } if (error) - goto unlock_entry; + goto finish_iomap; + + if (ops->iomap_end) { + error = ops->iomap_end(inode, pos, PAGE_SIZE, + PAGE_SIZE, flags, &iomap); + if (error) + goto unlock_entry; + } if (!radix_tree_exceptional_entry(entry)) { vmf->page = entry; return VM_FAULT_LOCKED; @@ -1230,8 +1237,15 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, break; case IOMAP_UNWRITTEN: case IOMAP_HOLE: - if (!(vmf->flags & FAULT_FLAG_WRITE)) + if (!(vmf->flags & FAULT_FLAG_WRITE)) { + if (ops->iomap_end) { + error = ops->iomap_end(inode, pos, PAGE_SIZE, + PAGE_SIZE, flags, &iomap); + if (error) + goto unlock_entry; + } return dax_load_hole(mapping, entry, vmf); + } /*FALLTHRU*/ default: WARN_ON_ONCE(1); @@ -1239,6 +1253,17 @@ int dax_iomap_fault(struct vm_area_struct *vma, struct vm_fault *vmf, break; } + finish_iomap: + if (ops->iomap_end) { + if (error) { + /* keep previous error */ + ops->iomap_end(inode, pos, PAGE_SIZE, PAGE_SIZE, flags, + &iomap); + } else { + error = ops->iomap_end(inode, pos, PAGE_SIZE, + PAGE_SIZE, flags, &iomap); + } + } unlock_entry: put_locked_mapping_entry(mapping, vmf->pgoff, entry); out: -- 2.7.4
