source: trunk/server/common/patches/openafs-d_splice_alias-reference.patch @ 2656

Last change on this file since 2656 was 2655, checked in by andersk, 10 years ago
openafs: Linux: d_splice_alias may drop inode reference on error Patch from http://gerrit.openafs.org/11643
File size: 2.1 KB

  • src/afs/LINUX/osi_vnodeops.c 

    From 1c576fdf9f05c6af7b5b029ba010a76bed48488e Mon Sep 17 00:00:00 2001
From: Marc Dionne <marc.dionne@your-file-system.com>
Date: Thu, 18 Dec 2014 08:43:22 -0500
Subject: [PATCH] Linux: d_splice_alias may drop inode reference on error

d_splice_alias now drops the inode reference on error, so we
need to grab an extra one to make sure that the inode doesn't
go away, and release it when done if there was no error.

For kernels that may not drop the reference, provide an
additional iput() within an ifdef.  This could be hooked up
to a configure option to allow building a module for a kernel
that is known not to drop the reference on error.  That hook
is not provided here.  Affected kernels should be the early
3.17 ones (3.17 - 3.17.2); 3.16 and older kernels should not
return errors here.

Change-Id: Id1786ac2227b4d8e0ae801fe59c15a0ecd975bed
---
 src/afs/LINUX/osi_vnodeops.c | 25 ++++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index b2ab9d5..3723cf8 100644
    a b afs_linux_lookup(struct inode *dip, struct dentry *dp) 
    16121612        ip->i_flags |= S_AUTOMOUNT;
    16131613#endif
    16141614    }
     1615    /*
     1616     * Take an extra reference so the inode doesn't go away if
     1617     * d_splice_alias drops our reference on error.
     1618     */
     1619    if (ip)
     1620        igrab(ip);
     1621
    16151622    newdp = d_splice_alias(ip, dp);
    16161623
    16171624 done:
    … … afs_linux_lookup(struct inode *dip, struct dentry *dp) 
    16251632         * d_splice_alias can return an error (EIO) if there is an existing
    16261633         * connected directory alias for this dentry.
    16271634         */
    1628         if (!IS_ERR(newdp))
     1635        if (!IS_ERR(newdp)) {
     1636            iput(ip);
    16291637            return newdp;
    1630         else {
     1638        } else {
    16311639            d_add(dp, ip);
     1640            /*
     1641             * Depending on the kernel version, d_splice_alias may or may
     1642             * not drop the inode reference on error.  If it didn't, do it
     1643             * here.
     1644             */
     1645#if defined(D_SPLICE_ALIAS_LEAK_ON_ERROR)
     1646            iput(ip);
     1647#endif
    16321648            return NULL;
    16331649        }
    1634     } else
     1650    } else {
     1651        if (ip)
     1652            iput(ip);
    16351653        return ERR_PTR(afs_convert_code(code));
     1654    }
    16361655}
    16371656
    16381657static int
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