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>
This commit is contained in:
Christoph Hellwig 2018-06-01 09:03:08 -07:00 committed by Darrick J. Wong
parent 57fc505d11
commit 89eb1906a9
2 changed files with 37 additions and 0 deletions

View File

@ -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);

View File

@ -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: