[grr... wrong To: on that one; instead of going it akpm it went to George, in one too many copies; my apologies...] On Thu, Nov 24, 2011 at 05:50:03PM +0000, Al Viro wrote: > On Thu, Nov 24, 2011 at 05:38:29PM +0000, Al Viro wrote: > > Said that, I'm not buying the theory of open assigning to ->f_mapping and > > screwing it up; all such assignments end up with ->i_mapping of *some* > > inode, as far as I can see from cursory grep over the tree. Just in case: > > do you have CONFIG_FS_POSIX_ACL set? > > BTW, why are we going through that dance with ->host->i_mapping anyway? > It had been introduced by commit by akpm back in 2004 and from my reading > of the commit message it was an overkill even back then. Basically, > that call got moved to the point past the call of ->open() (good, ->f_mapping > could've been changed by it) *and* converted from ->f_mapping to > ->f_mapping->host->i_mapping, which is useless. Definitely so in the > case mentioned in that commit (blkdev_open() sets ->f_mapping > bdev->bd_inode->i_mapping and that thing will have ->host pointing > back to bdev->bd_inode). Commit was in BK, its copy in historical tree > is commit 1c211088833a27daa4512348bcae9890e8cf92d4 > Author: Andrew Morton <akpm@xxxxxxxx> > Date: Wed May 26 17:35:42 2004 -0700 > > [PATCH] Fix the setting of file->f_ra on block-special files > > We need to set file->f_ra _after_ calling blkdev_open(), when inode->i_mapping > points at the right thing. And we need to get it from > inode->i_mapping->host->i_mapping too, which represents the underlying device. > > Also, don't test for null file->f_mapping in the O_DIRECT checks. > > Signed-off-by: Andrew Morton <akpm@xxxxxxxx> > > and the only difference wrt setting ->f_mapping on bdev open back then > is that it used to be done in do_open() instead of blkdev_open() itself. > So I don't understand what that part of changes had been for... Andrew? > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
