Messages in this thread | | | Date | Mon, 30 Sep 2002 20:57:58 +0200 | Subject | Re: [PATCH] 2.4.20 Direct IO patch for NFS. (Note: a trivial API change...) | From | Trond Myklebust <> |
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>>>>> " " == Matthew Wilcox <willy@debian.org> writes:
>> -static int blkdev_direct_IO(int rw, struct inode * inode, >> struct kiobuf * iobuf, unsigned long blocknr, int blocksize) >> +static int blkdev_direct_IO(int rw, struct file * filp, struct >> kiobuf * iobuf, unsigned long blocknr, int blocksize) { >> + struct inode * inode = >> filp->f_dentry->d_inode->i_mapping->host; >> return generic_direct_IO(rw, inode, iobuf, blocknr, blocksize, >> blkdev_get_block); } >>
> isn't that two dereferences more than necessary for a local > filesystem?
IIRC this is an issue with block filesystems: the i_mapping->host may differ from d_inode.
It is in any case just the exact same dereference that is being made in the current version of generic_file_direct_IO(). The API change simply moves this dereference down into the filesystem code.
Cheers, Trond - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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