[PATCH 03/12] iomap: add a IOMAP_ATOMIC flag

[Christoph Hellwig]

To pass through O_ATOMIC to the iomap_begin methods.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 fs/iomap.c            | 13 +++++++++++--
 include/linux/iomap.h |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/iomap.c b/fs/iomap.c
index 16a9d2b89cb6..096cbf573932 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -237,6 +237,10 @@ iomap_file_buffered_write(struct kiocb *iocb, struct 
iov_iter *iter,
 {
        struct inode *inode = iocb->ki_filp->f_mapping->host;
        loff_t pos = iocb->ki_pos, ret = 0, written = 0;
+       unsigned flags = IOMAP_WRITE;
+
+       if (iocb->ki_filp->f_flags & O_ATOMIC)
+               flags |= IOMAP_ATOMIC;
 
        while (iov_iter_count(iter)) {
                ret = iomap_apply(inode, pos, iov_iter_count(iter),
@@ -452,8 +456,12 @@ int iomap_page_mkwrite(struct vm_area_struct *vma, struct 
vm_fault *vmf,
        struct inode *inode = file_inode(vma->vm_file);
        unsigned long length;
        loff_t offset, size;
+       unsigned flags = IOMAP_WRITE | IOMAP_FAULT;
        ssize_t ret;
 
+       if (vma->vm_file->f_flags & O_ATOMIC)
+               flags |= IOMAP_ATOMIC;
+
        lock_page(page);
        size = i_size_read(inode);
        if ((page->mapping != inode->i_mapping) ||
@@ -471,8 +479,7 @@ int iomap_page_mkwrite(struct vm_area_struct *vma, struct 
vm_fault *vmf,
 
        offset = page_offset(page);
        while (length > 0) {
-               ret = iomap_apply(inode, offset, length,
-                               IOMAP_WRITE | IOMAP_FAULT, ops, page,
+               ret = iomap_apply(inode, offset, length, flags, ops, page,
                                iomap_page_mkwrite_actor);
                if (unlikely(ret <= 0))
                        goto out_unlock;
@@ -883,6 +890,8 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
        } else {
                dio->flags |= IOMAP_DIO_WRITE;
                flags |= IOMAP_WRITE;
+               if (iocb->ki_filp->f_flags & O_ATOMIC)
+                       flags |= IOMAP_ATOMIC;
        }
 
        if (mapping->nrpages) {
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 891459caa278..a670ff18ccd6 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -51,6 +51,7 @@ struct iomap {
 #define IOMAP_REPORT           (1 << 2) /* report extent status, e.g. FIEMAP */
 #define IOMAP_FAULT            (1 << 3) /* mapping for page fault */
 #define IOMAP_DIRECT           (1 << 4) /* direct I/O */
+#define IOMAP_ATOMIC           (1 << 5) /* atomic write vs power fail */
 
 struct iomap_ops {
        /*
-- 
2.11.0