Re: [PATCH 10/33] iomap: add an iomap-based bmap implementation
flat view
From: Darrick J. Wong <hidden>
Date: 2018-05-09 16:46:28
Also in:
linux-fsdevel, linux-mm, linux-xfs
On Wed, May 09, 2018 at 09:48:07AM +0200, Christoph Hellwig wrote:
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..
You /can/ check these... if (iomap->bdev != inode->i_sb->s_bdev) return 0; if (iomap->flags & IOMAP_F_SHARED) return 0;
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Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/iomap.c | 29 +++++++++++++++++++++++++++++ include/linux/iomap.h | 3 +++ 2 files changed, 32 insertions(+)diff --git a/fs/iomap.c b/fs/iomap.c index af525cb47339..049e0c4aacac 100644 --- a/fs/iomap.c +++ b/fs/iomap.c@@ -1201,3 +1201,32 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, return ret; } EXPORT_SYMBOL_GPL(iomap_dio_rw); + +static loff_t +iomap_bmap_actor(struct inode *inode, loff_t pos, loff_t length, + void *data, struct iomap *iomap) +{ + sector_t *bno = data; + + if (iomap->type == IOMAP_MAPPED) + *bno = (iomap->addr + pos - iomap->offset) >> inode->i_blkbits;
Does this need to be careful w.r.t. overflow on systems where sector_t is a 32-bit unsigned long? Also, ioctl_fibmap() typecasts the returned sector_t to an int, which also seems broken. I agree the interface needs to die, but ioctls take a long time to deprecate. --D
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+ 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 19a07de28212..07f73224c38b 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;@@ -95,6 +96,8 @@ 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:-- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html