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authorChristoph Hellwig <hch@lst.de>2018-06-01 19:03:08 +0300
committerDarrick J. Wong <darrick.wong@oracle.com>2018-06-02 04:37:33 +0300
commit89eb1906a9530ef694b2a5817c9498997722754f (patch)
tree03e9fcdf51b0203c380ff8f7086a61a8f286f9d4
parent57fc505d119d6e6bdf9b9b713215616a8cd2b8de (diff)
downloadlinux-89eb1906a9530ef694b2a5817c9498997722754f.tar.xz
iomap: add an iomap-based bmap implementation
This adds a simple iomap-based implementation of the legacy ->bmap interface. Note that we can't easily add checks for rt or reflink files, so these will have to remain in the callers. This interface just needs to die.. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
-rw-r--r--fs/iomap.c34
-rw-r--r--include/linux/iomap.h3
2 files changed, 37 insertions, 0 deletions
diff --git a/fs/iomap.c b/fs/iomap.c
index 74cdf8b5bbb0..b0bc928672af 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -1307,3 +1307,37 @@ int iomap_swapfile_activate(struct swap_info_struct *sis,
}
EXPORT_SYMBOL_GPL(iomap_swapfile_activate);
#endif /* CONFIG_SWAP */
+
+static loff_t
+iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length,
+ void *data, struct iomap *iomap)
+{
+ sector_t *bno = data, addr;
+
+ if (iomap->type == IOMAP_MAPPED) {
+ addr = (pos - iomap->offset + iomap->addr) >> inode->i_blkbits;
+ if (addr > INT_MAX)
+ WARN(1, "would truncate bmap result\n");
+ else
+ *bno = addr;
+ }
+ return 0;
+}
+
+/* legacy ->bmap interface. 0 is the error return (!) */
+sector_t
+iomap_bmap(struct address_space *mapping, sector_t bno,
+ const struct iomap_ops *ops)
+{
+ struct inode *inode = mapping->host;
+ loff_t pos = bno >> inode->i_blkbits;
+ unsigned blocksize = i_blocksize(inode);
+
+ if (filemap_write_and_wait(mapping))
+ return 0;
+
+ bno = 0;
+ iomap_apply(inode, pos, blocksize, 0, ops, &bno, iomap_bmap_actor);
+ return bno;
+}
+EXPORT_SYMBOL_GPL(iomap_bmap);
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 819e0cd2a950..a044a824da85 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -4,6 +4,7 @@
#include <linux/types.h>
+struct address_space;
struct fiemap_extent_info;
struct inode;
struct iov_iter;
@@ -100,6 +101,8 @@ loff_t iomap_seek_hole(struct inode *inode, loff_t offset,
const struct iomap_ops *ops);
loff_t iomap_seek_data(struct inode *inode, loff_t offset,
const struct iomap_ops *ops);
+sector_t iomap_bmap(struct address_space *mapping, sector_t bno,
+ const struct iomap_ops *ops);
/*
* Flags for direct I/O ->end_io: