4 files changed, 53 insertions, 80 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 7575cfc3ad15..4a28fa91e3b1 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -200,7 +200,7 @@ xfs_setfilesize_trans_alloc(
  * Update on-disk file size now that data has been written to disk.
  */
 STATIC int
-xfs_setfilesize(
+__xfs_setfilesize(
         struct xfs_inode        *ip,
         struct xfs_trans        *tp,
         xfs_off_t               offset,
@@ -225,6 +225,23 @@ xfs_setfilesize(
         return xfs_trans_commit(tp);
 }
 
+int
+xfs_setfilesize(
+        struct xfs_inode        *ip,
+        xfs_off_t               offset,
+        size_t                  size)
+{
+        struct xfs_mount        *mp = ip->i_mount;
+        struct xfs_trans        *tp;
+        int                     error;
+
+        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp);
+        if (error)
+                return error;
+
+        return __xfs_setfilesize(ip, tp, offset, size);
+}
+
 STATIC int
 xfs_setfilesize_ioend(
         struct xfs_ioend        *ioend,
@@ -247,7 +264,7 @@ xfs_setfilesize_ioend(
                 return error;
         }
 
-        return xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
+        return __xfs_setfilesize(ip, tp, ioend->io_offset, ioend->io_size);
 }
 
 /*
@@ -1336,13 +1353,12 @@ xfs_end_io_direct_write(
 {
         struct inode            *inode = file_inode(iocb->ki_filp);
         struct xfs_inode        *ip = XFS_I(inode);
-        struct xfs_mount        *mp = ip->i_mount;
         uintptr_t               flags = (uintptr_t)private;
         int                     error = 0;
 
         trace_xfs_end_io_direct_write(ip, offset, size);
 
-        if (XFS_FORCED_SHUTDOWN(mp))
+        if (XFS_FORCED_SHUTDOWN(ip->i_mount))
                 return -EIO;
 
         if (size <= 0)
@@ -1380,14 +1396,9 @@ xfs_end_io_direct_write(
 
                 error = xfs_iomap_write_unwritten(ip, offset, size);
         } else if (flags & XFS_DIO_FLAG_APPEND) {
-                struct xfs_trans *tp;
-
                 trace_xfs_end_io_direct_write_append(ip, offset, size);
 
-                error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0,
-                                &tp);
-                if (!error)
-                        error = xfs_setfilesize(ip, tp, offset, size);
+                error = xfs_setfilesize(ip, offset, size);
         }
 
         return error;
diff --git a/fs/xfs/xfs_aops.h b/fs/xfs/xfs_aops.h
index bf2d9a141a73..1950e3bca2ac 100644
--- a/fs/xfs/xfs_aops.h
+++ b/fs/xfs/xfs_aops.h
@@ -62,6 +62,7 @@ int	xfs_get_blocks_dax_fault(struct inode *inode, sector_t offset,
 
 int     xfs_end_io_direct_write(struct kiocb *iocb, loff_t offset,
                 ssize_t size, void *private);
+int     xfs_setfilesize(struct xfs_inode *ip, xfs_off_t offset, size_t size);
 
 extern void xfs_count_page_state(struct page *, int *, int *);
 extern struct block_device *xfs_find_bdev_for_inode(struct inode *);
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index b927ea9abe33..c68517b0f248 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -333,10 +333,7 @@ xfs_file_dax_read(
         struct kiocb            *iocb,
         struct iov_iter         *to)
 {
-        struct address_space    *mapping = iocb->ki_filp->f_mapping;
-        struct inode            *inode = mapping->host;
-        struct xfs_inode        *ip = XFS_I(inode);
-        struct iov_iter         data = *to;
+        struct xfs_inode        *ip = XFS_I(iocb->ki_filp->f_mapping->host);
         size_t                  count = iov_iter_count(to);
         ssize_t                 ret = 0;
 
@@ -346,11 +343,7 @@ xfs_file_dax_read(
                 return 0; /* skip atime */
 
         xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
-        ret = dax_do_io(iocb, inode, &data, xfs_get_blocks_direct, NULL, 0);
-        if (ret > 0) {
-                iocb->ki_pos += ret;
-                iov_iter_advance(to, ret);
-        }
+        ret = iomap_dax_rw(iocb, to, &xfs_iomap_ops);
         xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
 
         file_accessed(iocb->ki_filp);
@@ -712,70 +705,32 @@ xfs_file_dax_write(
         struct kiocb            *iocb,
         struct iov_iter         *from)
 {
-        struct address_space    *mapping = iocb->ki_filp->f_mapping;
-        struct inode            *inode = mapping->host;
+        struct inode            *inode = iocb->ki_filp->f_mapping->host;
         struct xfs_inode        *ip = XFS_I(inode);
-        struct xfs_mount        *mp = ip->i_mount;
-        ssize_t                 ret = 0;
-        int                     unaligned_io = 0;
-        int                     iolock;
-        struct iov_iter         data;
+        int                     iolock = XFS_IOLOCK_EXCL;
+        ssize_t                 ret, error = 0;
+        size_t                  count;
+        loff_t                  pos;
 
-        /* "unaligned" here means not aligned to a filesystem block */
-        if ((iocb->ki_pos & mp->m_blockmask) ||
-            ((iocb->ki_pos + iov_iter_count(from)) & mp->m_blockmask)) {
-                unaligned_io = 1;
-                iolock = XFS_IOLOCK_EXCL;
-        } else if (mapping->nrpages) {
-                iolock = XFS_IOLOCK_EXCL;
-        } else {
-                iolock = XFS_IOLOCK_SHARED;
-        }
         xfs_rw_ilock(ip, iolock);
-
         ret = xfs_file_aio_write_checks(iocb, from, &iolock);
         if (ret)
                 goto out;
 
-        /*
-         * Yes, even DAX files can have page cache attached to them:  A zeroed
-         * page is inserted into the pagecache when we have to serve a write
-         * fault on a hole.  It should never be dirtied and can simply be
-         * dropped from the pagecache once we get real data for the page.
-         *
-         * XXX: This is racy against mmap, and there's nothing we can do about
-         * it. dax_do_io() should really do this invalidation internally as
-         * it will know if we've allocated over a holei for this specific IO and
-         * if so it needs to update the mapping tree and invalidate existing
-         * PTEs over the newly allocated range. Remove this invalidation when
-         * dax_do_io() is fixed up.
-         */
-        if (mapping->nrpages) {
-                loff_t end = iocb->ki_pos + iov_iter_count(from) - 1;
+        pos = iocb->ki_pos;
+        count = iov_iter_count(from);
 
-                ret = invalidate_inode_pages2_range(mapping,
-                                                    iocb->ki_pos >> PAGE_SHIFT,
-                                                    end >> PAGE_SHIFT);
-                WARN_ON_ONCE(ret);
-        }
+        trace_xfs_file_dax_write(ip, count, pos);
 
-        if (iolock == XFS_IOLOCK_EXCL && !unaligned_io) {
-                xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
-                iolock = XFS_IOLOCK_SHARED;
+        ret = iomap_dax_rw(iocb, from, &xfs_iomap_ops);
+        if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
+                i_size_write(inode, iocb->ki_pos);
+                error = xfs_setfilesize(ip, pos, ret);
         }
 
-        trace_xfs_file_dax_write(ip, iov_iter_count(from), iocb->ki_pos);
-
-        data = *from;
-        ret = dax_do_io(iocb, inode, &data, xfs_get_blocks_direct,
-                        xfs_end_io_direct_write, 0);
-        if (ret > 0) {
-                iocb->ki_pos += ret;
-                iov_iter_advance(from, ret);
-        }
 out:
         xfs_rw_iunlock(ip, iolock);
-        return ret;
+        return error ? error : ret;
 }
 
 STATIC ssize_t
@@ -1514,7 +1469,7 @@ xfs_filemap_page_mkwrite(
         xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
 
         if (IS_DAX(inode)) {
-                ret = dax_mkwrite(vma, vmf, xfs_get_blocks_dax_fault);
+                ret = iomap_dax_fault(vma, vmf, &xfs_iomap_ops);
         } else {
                 ret = iomap_page_mkwrite(vma, vmf, &xfs_iomap_ops);
                 ret = block_page_mkwrite_return(ret);
@@ -1548,7 +1503,7 @@ xfs_filemap_fault(
                  * changes to xfs_get_blocks_direct() to map unwritten extent
                  * ioend for conversion on read-only mappings.
                  */
-                ret = dax_fault(vma, vmf, xfs_get_blocks_dax_fault);
+                ret = iomap_dax_fault(vma, vmf, &xfs_iomap_ops);
         } else
                 ret = filemap_fault(vma, vmf);
         xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f96c8ffce5f4..c08253e11545 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -934,11 +934,13 @@ error_on_bmapi_transaction:
         return error;
 }
 
-static inline bool imap_needs_alloc(struct xfs_bmbt_irec *imap, int nimaps)
+static inline bool imap_needs_alloc(struct inode *inode,
+                struct xfs_bmbt_irec *imap, int nimaps)
 {
         return !nimaps ||
                 imap->br_startblock == HOLESTARTBLOCK ||
-                imap->br_startblock == DELAYSTARTBLOCK;
+                imap->br_startblock == DELAYSTARTBLOCK ||
+                (IS_DAX(inode) && ISUNWRITTEN(imap));
 }
 
 static int
@@ -954,16 +956,18 @@ xfs_file_iomap_begin(
         struct xfs_bmbt_irec    imap;
         xfs_fileoff_t           offset_fsb, end_fsb;
         int                     nimaps = 1, error = 0;
+        unsigned                lockmode;
 
         if (XFS_FORCED_SHUTDOWN(mp))
                 return -EIO;
 
-        if ((flags & IOMAP_WRITE) && !xfs_get_extsz_hint(ip)) {
+        if ((flags & IOMAP_WRITE) &&
+            !IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
                 return xfs_file_iomap_begin_delay(inode, offset, length, flags,
                                 iomap);
         }
 
-        xfs_ilock(ip, XFS_ILOCK_EXCL);
+        lockmode = xfs_ilock_data_map_shared(ip);
 
         ASSERT(offset <= mp->m_super->s_maxbytes);
         if ((xfs_fsize_t)offset + length > mp->m_super->s_maxbytes)
@@ -974,11 +978,11 @@ xfs_file_iomap_begin(
         error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
                                &nimaps, XFS_BMAPI_ENTIRE);
         if (error) {
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
+                xfs_iunlock(ip, lockmode);
                 return error;
         }
 
-        if ((flags & IOMAP_WRITE) && imap_needs_alloc(&imap, nimaps)) {
+        if ((flags & IOMAP_WRITE) && imap_needs_alloc(inode, &imap, nimaps)) {
                 /*
                  * We cap the maximum length we map here to MAX_WRITEBACK_PAGES
                  * pages to keep the chunks of work done where somewhat symmetric
@@ -994,17 +998,19 @@ xfs_file_iomap_begin(
                  * xfs_iomap_write_direct() expects the shared lock. It
                  * is unlocked on return.
                  */
-                xfs_ilock_demote(ip, XFS_ILOCK_EXCL);
+                if (lockmode == XFS_ILOCK_EXCL)
+                        xfs_ilock_demote(ip, lockmode);
                 error = xfs_iomap_write_direct(ip, offset, length, &imap,
                                 nimaps);
                 if (error)
                         return error;
 
+                iomap->flags = IOMAP_F_NEW;
                 trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
         } else {
                 ASSERT(nimaps);
 
-                xfs_iunlock(ip, XFS_ILOCK_EXCL);
+                xfs_iunlock(ip, lockmode);
                 trace_xfs_iomap_found(ip, offset, length, 0, &imap);
         }