iomap: ignore non-shared or non-data blocks in xfs_file_dirty

xfs_file_dirty is used to unshare reflink blocks.  Rename the function
to xfs_file_unshare to better document that purpose, and skip iomaps
that are not shared and don't need zeroing.  This will allow to simplify
the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 8f9b54db381162c8d763a95e9cfadd3b1917afe2..30df87ac8349419f5f569e772404b81bab24892b 100644 (file)
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -887,12 +887,19 @@ __iomap_read_page(struct inode *inode, loff_t offset)
 }
 
 static loff_t
-iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
+iomap_unshare_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
                struct iomap *iomap)
 {
        long status = 0;
        ssize_t written = 0;
 
+       /* don't bother with blocks that are not shared to start with */
+       if (!(iomap->flags & IOMAP_F_SHARED))
+               return length;
+       /* don't bother with holes or unwritten extents */
+       if (iomap->type == IOMAP_HOLE || iomap->type == IOMAP_UNWRITTEN)
+               return length;
+
        do {
                struct page *page, *rpage;
                unsigned long offset;   /* Offset into pagecache page */
@@ -932,14 +939,14 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
 }
 
 int
-iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
+iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
                const struct iomap_ops *ops)
 {
        loff_t ret;
 
        while (len) {
                ret = iomap_apply(inode, pos, len, IOMAP_WRITE, ops, NULL,
-                               iomap_dirty_actor);
+                               iomap_unshare_actor);
                if (ret <= 0)
                        return ret;
                pos += ret;
@@ -948,7 +955,7 @@ iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
 
        return 0;
 }
-EXPORT_SYMBOL_GPL(iomap_file_dirty);
+EXPORT_SYMBOL_GPL(iomap_file_unshare);
 
 static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset,
                unsigned bytes, struct iomap *iomap)

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 0f08153b4994190fcd21d8b4fd9f6914ae908cb4..a9634110c78306a6dee9a67cb0b0c70048489c12 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1442,7 +1442,7 @@ xfs_reflink_dirty_extents(
                        flen = XFS_FSB_TO_B(mp, rlen);
                        if (fpos + flen > isize)
                                flen = isize - fpos;
-                       error = iomap_file_dirty(VFS_I(ip), fpos, flen,
+                       error = iomap_file_unshare(VFS_I(ip), fpos, flen,
                                        &xfs_iomap_ops);
                        xfs_ilock(ip, XFS_ILOCK_EXCL);
                        if (error)

diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 8016700e61214d5dab6da040e36ab303c8dbf0de..1623851ade9003faaea51096cf17dd7954e593b7 100644 (file)
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -168,7 +168,7 @@ int iomap_migrate_page(struct address_space *mapping, struct page *newpage,
 #else
 #define iomap_migrate_page NULL
 #endif
-int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
+int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
                const struct iomap_ops *ops);
 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,
                bool *did_zero, const struct iomap_ops *ops);