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authorCasey Schaufler <casey@schaufler-ca.com>2020-04-25 01:23:04 +0300
committerCasey Schaufler <casey@schaufler-ca.com>2020-05-07 00:46:26 +0300
commit921bb1cbb31bb0424b47de52174da20367449c8e (patch)
treef7beeab56ecc611b9bbea848db8105d7d94801fa /security/smack/smack_lsm.c
parent84e99e58e8d1e26f04c097f4266e431a33987f36 (diff)
downloadlinux-921bb1cbb31bb0424b47de52174da20367449c8e.tar.xz
Smack:- Remove mutex lock "smk_lock" from inode_smack
"smk_lock" mutex is used during inode instantiation in smack_d_instantiate()function. It has been used to avoid simultaneous access on same inode security structure. Since smack related initialization is done only once i.e during inode creation. If the inode has already been instantiated then smack_d_instantiate() function just returns without doing anything. So it means mutex lock is required only during inode creation. But since 2 processes can't create same inodes or files simultaneously. Also linking or some other file operation can't be done simultaneously when the file is getting created since file lookup will fail before dentry inode linkup which is done after smack initialization. So no mutex lock is required in inode_smack structure. It will save memory as well as improve some performance. If 40000 inodes are created in system, it will save 1.5 MB on 32-bit systems & 2.8 MB on 64-bit systems. Signed-off-by: Vishal Goel <vishal.goel@samsung.com> Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Diffstat (limited to 'security/smack/smack_lsm.c')
-rw-r--r--security/smack/smack_lsm.c8
1 files changed, 2 insertions, 6 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 14bf2f4aea3b..339356939018 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -314,7 +314,6 @@ static void init_inode_smack(struct inode *inode, struct smack_known *skp)
isp->smk_inode = skp;
isp->smk_flags = 0;
- mutex_init(&isp->smk_lock);
}
/**
@@ -3264,13 +3263,12 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
isp = smack_inode(inode);
- mutex_lock(&isp->smk_lock);
/*
* If the inode is already instantiated
* take the quick way out
*/
if (isp->smk_flags & SMK_INODE_INSTANT)
- goto unlockandout;
+ return;
sbp = inode->i_sb;
sbsp = sbp->s_security;
@@ -3321,7 +3319,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
break;
}
isp->smk_flags |= SMK_INODE_INSTANT;
- goto unlockandout;
+ return;
}
/*
@@ -3456,8 +3454,6 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
-unlockandout:
- mutex_unlock(&isp->smk_lock);
return;
}