| Message ID | 1587732920-49120-1-git-send-email-vishal.goel@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/1] Smack:- Remove mutex lock "smk_lock" from inode_smack structure. | expand |
On 4/24/2020 5:55 AM, Vishal Goel wrote: > "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> I am taking this for 5.8. Thank you. > --- > security/smack/smack.h | 1 - > security/smack/smack_lsm.c | 8 ++------ > 2 files changed, 2 insertions(+), 7 deletions(-) > > diff --git a/security/smack/smack.h b/security/smack/smack.h > index 62529f3..fd09dc8 100644 > --- a/security/smack/smack.h > +++ b/security/smack/smack.h > @@ -109,7 +109,6 @@ struct inode_smack { > struct smack_known *smk_inode; /* label of the fso */ > struct smack_known *smk_task; /* label of the task */ > struct smack_known *smk_mmap; /* label of the mmap domain */ > - struct mutex smk_lock; /* initialization lock */ > int smk_flags; /* smack inode flags */ > struct rcu_head smk_rcu; /* for freeing inode_smack */ > }; > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index 2862fc3..10c2bdd 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -317,7 +317,6 @@ 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); > } > > /** > @@ -3274,13 +3273,12 @@ 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; > @@ -3331,7 +3329,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) > break; > } > isp->smk_flags |= SMK_INODE_INSTANT; > - goto unlockandout; > + return; > } > > /* > @@ -3466,8 +3464,6 @@ 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; > } >
diff --git a/security/smack/smack.h b/security/smack/smack.h index 62529f3..fd09dc8 100644 --- a/security/smack/smack.h +++ b/security/smack/smack.h @@ -109,7 +109,6 @@ struct inode_smack { struct smack_known *smk_inode; /* label of the fso */ struct smack_known *smk_task; /* label of the task */ struct smack_known *smk_mmap; /* label of the mmap domain */ - struct mutex smk_lock; /* initialization lock */ int smk_flags; /* smack inode flags */ struct rcu_head smk_rcu; /* for freeing inode_smack */ }; diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 2862fc3..10c2bdd 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -317,7 +317,6 @@ 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); } /** @@ -3274,13 +3273,12 @@ 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; @@ -3331,7 +3329,7 @@ static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) break; } isp->smk_flags |= SMK_INODE_INSTANT; - goto unlockandout; + return; } /* @@ -3466,8 +3464,6 @@ 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; }