diff options
Diffstat (limited to 'debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch')
| -rw-r--r-- | debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch b/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch new file mode 100644 index 00000000..d32acdd0 --- /dev/null +++ b/debian/patches/0005-libtrivfs-lock-less-reference-counting-for-trivfs_pr.patch @@ -0,0 +1,176 @@ +From af1a321ffb5df24b3a5fa866ab2aa9c5b03f358c Mon Sep 17 00:00:00 2001 +From: Justus Winter <4winter@informatik.uni-hamburg.de> +Date: Tue, 6 May 2014 19:07:13 +0200 +Subject: [PATCH 5/5] libtrivfs: lock-less reference counting for trivfs_protid + objects + +* libtrivfs/trivfs.h (struct trivfs_protid): Use refcount_t for field +refcnt. +(struct trivfs_control): Remove unused field lock. +* libtrivfs/open.c (trivfs_open): Initialize refcnt. +* libtrivfs/io-reauthenticate.c (trivfs_S_io_reauthenticate): Adjust +accordingly. +* libtrivfs/io-restrict-auth.c (trivfs_S_io_restrict_auth): Likewise. +* libtrivfs/protid-clean.c (trivfs_clean_protid): Likewise. +* libtrivfs/protid-dup.c (trivfs_protid_dup): Likewise. +* libtrivfs/cntl-create.c (trivfs_create_control): Drop the mutex +initialization. +* libtrivfs/peropen-make.c (trivfs_make_peropen): Initialize refcnt. +* libtrivfs/peropen-rele.c (trivfs_release_peropen): Adjust accordingly. +* libtrivfs/protid-make.c (trivfs_start_protid): Likewise. Also, the +node must no longer be locked, adjust comment accordingly. +(trivfs_create_protid): Likewise. +--- + libtrivfs/cntl-create.c | 1 - + libtrivfs/io-reauthenticate.c | 5 +---- + libtrivfs/io-restrict-auth.c | 4 +--- + libtrivfs/open.c | 2 +- + libtrivfs/protid-clean.c | 25 ++++++++++++++----------- + libtrivfs/protid-dup.c | 5 +---- + libtrivfs/trivfs.h | 4 ++-- + 7 files changed, 20 insertions(+), 26 deletions(-) + +diff --git a/libtrivfs/cntl-create.c b/libtrivfs/cntl-create.c +index 910daf3..eb9a834 100644 +--- a/libtrivfs/cntl-create.c ++++ b/libtrivfs/cntl-create.c +@@ -85,7 +85,6 @@ trivfs_create_control (mach_port_t underlying, + } + + (*control)->hook = 0; +- pthread_mutex_init (&(*control)->lock, NULL); + } + + out: +diff --git a/libtrivfs/io-reauthenticate.c b/libtrivfs/io-reauthenticate.c +index 7677697..df0ed2e 100644 +--- a/libtrivfs/io-reauthenticate.c ++++ b/libtrivfs/io-reauthenticate.c +@@ -62,11 +62,8 @@ trivfs_S_io_reauthenticate (struct trivfs_protid *cred, + newcred->isroot = 1; + + newcred->hook = cred->hook; +- +- pthread_mutex_lock (&cred->po->cntl->lock); + newcred->po = cred->po; +- newcred->po->refcnt++; +- pthread_mutex_unlock (&cred->po->cntl->lock); ++ refcount_ref (&newcred->po->refcnt); + + do + err = io_restrict_auth (newcred->po->cntl->underlying, &newcred->realnode, +diff --git a/libtrivfs/io-restrict-auth.c b/libtrivfs/io-restrict-auth.c +index 65b4fd6..39670fe 100644 +--- a/libtrivfs/io-restrict-auth.c ++++ b/libtrivfs/io-restrict-auth.c +@@ -110,10 +110,8 @@ trivfs_S_io_restrict_auth (struct trivfs_protid *cred, + } + + newcred->isroot = 0; +- pthread_mutex_lock (&cred->po->cntl->lock); + newcred->po = cred->po; +- newcred->po->refcnt++; +- pthread_mutex_unlock (&cred->po->cntl->lock); ++ refcount_ref (&newcred->po->refcnt); + if (cred->isroot && idvec_contains (user->uids, 0)) + newcred->isroot = 1; + newcred->user = user; +diff --git a/libtrivfs/open.c b/libtrivfs/open.c +index f64d2ff..97e70a1 100644 +--- a/libtrivfs/open.c ++++ b/libtrivfs/open.c +@@ -40,7 +40,7 @@ trivfs_open (struct trivfs_control *cntl, + + ports_port_ref (cntl); + +- po->refcnt = 1; ++ refcount_init (&po->refcnt, 1); + po->cntl = cntl; + po->openmodes = flags; + po->hook = 0; +diff --git a/libtrivfs/protid-clean.c b/libtrivfs/protid-clean.c +index f98da6a..815e731 100644 +--- a/libtrivfs/protid-clean.c ++++ b/libtrivfs/protid-clean.c +@@ -31,19 +31,22 @@ trivfs_clean_protid (void *arg) + (*trivfs_protid_destroy_hook) (cred); + + /* If we hold the only reference to the peropen, try to get rid of it. */ +- pthread_mutex_lock (&cntl->lock); +- if (cred->po->refcnt == 1 && trivfs_peropen_destroy_hook) ++ if (refcount_deref (&cred->po->refcnt) == 0) + { +- pthread_mutex_unlock (&cntl->lock); +- (*trivfs_peropen_destroy_hook) (cred->po); +- pthread_mutex_lock (&cntl->lock); ++ if (trivfs_protid_destroy_hook) ++ { ++ refcount_ref (&cred->po->refcnt); ++ (*trivfs_peropen_destroy_hook) (cred->po); ++ if (refcount_deref (&cred->po->refcnt) == 0) ++ goto free_po; ++ } ++ else ++ { ++ free_po: ++ ports_port_deref (cntl); ++ free (cred->po); ++ } + } +- if (--cred->po->refcnt == 0) +- { +- ports_port_deref (cntl); +- free (cred->po); +- } +- pthread_mutex_unlock (&cntl->lock); + + iohelp_free_iouser (cred->user); + +diff --git a/libtrivfs/protid-dup.c b/libtrivfs/protid-dup.c +index 6169603..75f3ca8 100644 +--- a/libtrivfs/protid-dup.c ++++ b/libtrivfs/protid-dup.c +@@ -35,11 +35,8 @@ trivfs_protid_dup (struct trivfs_protid *cred, struct trivfs_protid **dup) + + if (! err) + { +- pthread_mutex_lock (&cred->po->cntl->lock); + new->po = cred->po; +- new->po->refcnt++; +- pthread_mutex_unlock (&cred->po->cntl->lock); +- ++ refcount_ref (&new->po->refcnt); + new->isroot = cred->isroot; + + err = iohelp_dup_iouser (&new->user, cred->user); +diff --git a/libtrivfs/trivfs.h b/libtrivfs/trivfs.h +index bb456ff..8902338 100644 +--- a/libtrivfs/trivfs.h ++++ b/libtrivfs/trivfs.h +@@ -24,6 +24,7 @@ + #include <mach/mach.h> + #include <hurd/ports.h> + #include <hurd/iohelp.h> ++#include <refcount.h> + + struct trivfs_protid + { +@@ -41,14 +42,13 @@ struct trivfs_peropen + { + void *hook; /* for user use */ + int openmodes; +- int refcnt; ++ refcount_t refcnt; + struct trivfs_control *cntl; + }; + + struct trivfs_control + { + struct port_info pi; +- pthread_mutex_t lock; + struct port_class *protid_class; + struct port_bucket *protid_bucket; + mach_port_t filesys_id; +-- +2.0.0.rc0 + |