* [RFC PATCH userspace 5/6] selinux_restorecon: introduce selinux_restorecon_parallel(3)
2021-03-23 17:08 [RFC PATCH userspace 0/6] Parallel setfiles/restorecon Ondrej Mosnacek
` (3 preceding siblings ...)
2021-03-23 17:08 ` [RFC PATCH userspace 4/6] selinux_restorecon: add a global mutex to synchronize progress output Ondrej Mosnacek
@ 2021-03-23 17:08 ` Ondrej Mosnacek
2021-03-23 17:08 ` [RFC PATCH userspace 6/6] setfiles/restorecon: support parallel relabeling Ondrej Mosnacek
2021-03-24 9:58 ` [RFC PATCH userspace 0/6] Parallel setfiles/restorecon peter enderborg
6 siblings, 0 replies; 11+ messages in thread
From: Ondrej Mosnacek @ 2021-03-23 17:08 UTC (permalink / raw)
To: selinux
Refactor selinux_restorecon(3) to allow for distributing the relabeling
to multiple threads and add a new function
selinux_restorecon_parallel(3), which allows specifying the number of
threads to use. The existing selinux_restorecon(3) function maintains
the same interface and maintains the same behavior (i.e. relabeling is
done on a single thread).
The parallel implementation takes a simple approach of performing all
the directory tree traversal in a critical section and only letting the
relabeling of individual objects run in parallel. Thankfully, this
approach turns out to be efficient enough in practice, as shown by
restorecon benchmarks (detailed in a subsequent patch that switches
setfiles & restorecon to use selinux_restorecon_parallel(3)).
Note that to be able to use the parallelism, the calling application/
library must be explicitly linked to the libpthread library (statically
or dynamically). This is necessary to mantain the requirement that
libselinux shouldn't explicitly link with libpthread. (I don't know what
exactly was the reason behind this requirement as the commit logs are
fuzzy, but special care has been taken in the past to maintain it, so I
didn't want to break it...)
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
libselinux/include/selinux/restorecon.h | 14 +
libselinux/man/man3/selinux_restorecon.3 | 29 ++
.../man/man3/selinux_restorecon_parallel.3 | 1 +
libselinux/src/libselinux.map | 5 +
libselinux/src/selinux_internal.h | 14 +
libselinux/src/selinux_restorecon.c | 461 ++++++++++++------
6 files changed, 365 insertions(+), 159 deletions(-)
create mode 100644 libselinux/man/man3/selinux_restorecon_parallel.3
diff --git a/libselinux/include/selinux/restorecon.h b/libselinux/include/selinux/restorecon.h
index 466de39a..1821a3dc 100644
--- a/libselinux/include/selinux/restorecon.h
+++ b/libselinux/include/selinux/restorecon.h
@@ -2,6 +2,7 @@
#define _RESTORECON_H_
#include <sys/types.h>
+#include <stddef.h>
#include <stdarg.h>
#ifdef __cplusplus
@@ -23,6 +24,19 @@ extern "C" {
*/
extern int selinux_restorecon(const char *pathname,
unsigned int restorecon_flags);
+/**
+ * selinux_restorecon_parallel - Relabel files, optionally use more threads.
+ * @pathname: specifies file/directory to relabel.
+ * @restorecon_flags: specifies the actions to be performed when relabeling.
+ * @nthreads: specifies the number of threads to use (0 = use number of CPUs
+ * currently online)
+ *
+ * Same as selinux_restorecon(3), but allows to use multiple threads to do
+ * the work.
+ */
+extern int selinux_restorecon_parallel(const char *pathname,
+ unsigned int restorecon_flags,
+ size_t nthreads);
/*
* restorecon_flags options
*/
diff --git a/libselinux/man/man3/selinux_restorecon.3 b/libselinux/man/man3/selinux_restorecon.3
index ad637406..334d2930 100644
--- a/libselinux/man/man3/selinux_restorecon.3
+++ b/libselinux/man/man3/selinux_restorecon.3
@@ -11,6 +11,14 @@ selinux_restorecon \- restore file(s) default SELinux security contexts
.br
.BI "unsigned int " restorecon_flags ");"
.in
+.sp
+.BI "int selinux_restorecon_parallel(const char *" pathname ,
+.in +\w'int selinux_restorecon_parallel('u
+.br
+.BI "unsigned int " restorecon_flags ","
+.br
+.BI "size_t " nthreads ");"
+.in
.
.SH "DESCRIPTION"
.BR selinux_restorecon ()
@@ -187,6 +195,27 @@ unless the
.B SELINUX_RESTORECON_IGNORE_MOUNTS
flag has been set.
.RE
+.sp
+.BR selinux_restorecon_parallel()
+is similar to
+.BR selinux_restorecon (3),
+but accepts another parameter that allows to run relabeling over multiple
+threads:
+.sp
+.RS
+.IR nthreads
+specifies the number of threads to use during relabeling. When set to 1,
+the behavior is the same as calling
+.BR selinux_restorecon (3).
+When set to 0, the function will try to use as many threads as there are
+online CPU cores. When set to any other number, the function will try to use
+the given number of threads.
+.sp
+Note that to use the parallel relabeling capability, the calling process
+must be linked with the
+.B libpthread
+library (either at compile time or dynamically at run time). Otherwise the
+function will print a warning and fall back to the single threaded mode.
.
.SH "RETURN VALUE"
On success, zero is returned. On error, \-1 is returned and
diff --git a/libselinux/man/man3/selinux_restorecon_parallel.3 b/libselinux/man/man3/selinux_restorecon_parallel.3
new file mode 100644
index 00000000..092d8412
--- /dev/null
+++ b/libselinux/man/man3/selinux_restorecon_parallel.3
@@ -0,0 +1 @@
+.so man3/selinux_restorecon.3
diff --git a/libselinux/src/libselinux.map b/libselinux/src/libselinux.map
index 2a368e93..68a1ad32 100644
--- a/libselinux/src/libselinux.map
+++ b/libselinux/src/libselinux.map
@@ -240,3 +240,8 @@ LIBSELINUX_1.0 {
local:
*;
};
+
+LIBSELINUX_3.2 {
+ global:
+ selinux_restorecon_parallel;
+} LIBSELINUX_1.0;
diff --git a/libselinux/src/selinux_internal.h b/libselinux/src/selinux_internal.h
index 27e9ac53..bca9398a 100644
--- a/libselinux/src/selinux_internal.h
+++ b/libselinux/src/selinux_internal.h
@@ -69,6 +69,20 @@ extern int selinux_page_size ;
pthread_mutex_unlock(LOCK); \
} while (0)
+#pragma weak pthread_create
+#pragma weak pthread_cond_init
+#pragma weak pthread_cond_signal
+#pragma weak pthread_cond_destroy
+#pragma weak pthread_cond_wait
+
+/* check if all functions needed to do parallel operations are available */
+#define __pthread_supported ( \
+ pthread_create && \
+ pthread_cond_init && \
+ pthread_cond_destroy && \
+ pthread_cond_signal && \
+ pthread_cond_wait \
+)
#define SELINUXDIR "/etc/selinux/"
#define SELINUXCONFIG SELINUXDIR "config"
diff --git a/libselinux/src/selinux_restorecon.c b/libselinux/src/selinux_restorecon.c
index 3f3ac2e6..adbaeeae 100644
--- a/libselinux/src/selinux_restorecon.c
+++ b/libselinux/src/selinux_restorecon.c
@@ -621,7 +621,7 @@ out:
}
static int restorecon_sb(const char *pathname, const struct stat *sb,
- struct rest_flags *flags)
+ struct rest_flags *flags, bool first)
{
char *newcon = NULL;
char *curcon = NULL;
@@ -633,9 +633,9 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
if (rootpath) {
if (strncmp(rootpath, lookup_path, rootpathlen) != 0) {
- selinux_log(SELINUX_ERROR,
- "%s is not located in alt_rootpath %s\n",
- lookup_path, rootpath);
+ selinux_log_sync(SELINUX_ERROR,
+ "%s is not located in alt_rootpath %s\n",
+ lookup_path, rootpath);
return -1;
}
lookup_path += rootpathlen;
@@ -650,10 +650,10 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
sb->st_mode);
if (rc < 0) {
- if (errno == ENOENT && flags->warnonnomatch)
- selinux_log(SELINUX_INFO,
- "Warning no default label for %s\n",
- lookup_path);
+ if (errno == ENOENT && flags->warnonnomatch && first)
+ selinux_log_sync(SELINUX_INFO,
+ "Warning no default label for %s\n",
+ lookup_path);
return 0; /* no match, but not an error */
}
@@ -678,8 +678,8 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
rc = filespec_add(sb->st_ino, newcon, pathname, flags);
if (rc < 0) {
- selinux_log(SELINUX_ERROR,
- "filespec_add error: %s\n", pathname);
+ selinux_log_sync(SELINUX_ERROR,
+ "filespec_add error: %s\n", pathname);
freecon(newcon);
return -1;
}
@@ -692,8 +692,8 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
}
if (flags->log_matches)
- selinux_log(SELINUX_INFO, "%s matched by %s\n",
- pathname, newcon);
+ selinux_log_sync(SELINUX_INFO, "%s matched by %s\n",
+ pathname, newcon);
if (lgetfilecon_raw(pathname, &curcon) < 0) {
if (errno != ENODATA)
@@ -706,9 +706,9 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
if (!flags->set_specctx && curcon &&
(is_context_customizable(curcon) > 0)) {
if (flags->verbose) {
- selinux_log(SELINUX_INFO,
+ selinux_log_sync(SELINUX_INFO,
"%s not reset as customized by admin to %s\n",
- pathname, curcon);
+ pathname, curcon);
}
goto out;
}
@@ -734,10 +734,10 @@ static int restorecon_sb(const char *pathname, const struct stat *sb,
}
if (flags->verbose)
- selinux_log(SELINUX_INFO,
- "%s %s from %s to %s\n",
- updated ? "Relabeled" : "Would relabel",
- pathname, curcon, newcon);
+ selinux_log_sync(SELINUX_INFO,
+ "%s %s from %s to %s\n",
+ updated ? "Relabeled" : "Would relabel",
+ pathname, curcon, newcon);
if (flags->syslog_changes && !flags->nochange) {
if (curcon)
@@ -757,9 +757,9 @@ out1:
freecon(newcon);
return rc;
err:
- selinux_log(SELINUX_ERROR,
- "Could not set context for %s: %s\n",
- pathname, strerror(errno));
+ selinux_log_sync(SELINUX_ERROR,
+ "Could not set context for %s: %s\n",
+ pathname, strerror(errno));
rc = -1;
goto out1;
}
@@ -825,65 +825,217 @@ oom:
goto free;
}
+struct rest_state {
+ struct rest_flags flags;
+ dev_t dev_num;
+ struct statfs sfsb;
+ bool ignore_digest;
+ bool setrestorecondigest;
+ bool parallel;
-/*
- * Public API
- */
+ FTS *fts;
+ FTSENT *ftsent_first;
+ struct dir_hash_node *head, *current;
+ bool abort;
+ int error;
+ int saved_errno;
+ size_t inprogress;
+ pthread_cond_t cond_finish;
+ pthread_mutex_t mutex;
+};
-/* selinux_restorecon(3) - Main function that is responsible for labeling */
-int selinux_restorecon(const char *pathname_orig,
- unsigned int restorecon_flags)
+static void *selinux_restorecon_thread(void *arg)
{
- struct rest_flags flags;
+ struct rest_state *state = arg;
+ FTS *fts = state->fts;
+ FTSENT *ftsent;
+ int error;
+ char ent_path[PATH_MAX];
+ struct stat ent_st;
+ bool first = false;
+
+ if (state->parallel)
+ pthread_mutex_lock(&state->mutex);
+
+ if (state->ftsent_first) {
+ ftsent = state->ftsent_first;
+ state->ftsent_first = NULL;
+ first = true;
+ goto loop_body;
+ }
+
+ while ((errno = 0, ftsent = fts_read(fts)) != NULL) {
+loop_body:
+ /* If the FTS_XDEV flag is set and the device is different */
+ if (state->flags.set_xdev &&
+ ftsent->fts_statp->st_dev != state->dev_num)
+ continue;
+
+ switch (ftsent->fts_info) {
+ case FTS_DC:
+ selinux_log_sync(SELINUX_ERROR,
+ "Directory cycle on %s.\n",
+ ftsent->fts_path);
+ errno = ELOOP;
+ state->error = -1;
+ state->abort = true;
+ goto finish;
+ case FTS_DP:
+ continue;
+ case FTS_DNR:
+ selinux_log_sync(SELINUX_ERROR,
+ "Could not read %s: %s.\n",
+ ftsent->fts_path,
+ strerror(ftsent->fts_errno));
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ case FTS_NS:
+ selinux_log_sync(SELINUX_ERROR,
+ "Could not stat %s: %s.\n",
+ ftsent->fts_path,
+ strerror(ftsent->fts_errno));
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ case FTS_ERR:
+ selinux_log_sync(SELINUX_ERROR,
+ "Error on %s: %s.\n",
+ ftsent->fts_path,
+ strerror(ftsent->fts_errno));
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ case FTS_D:
+ if (state->sfsb.f_type == SYSFS_MAGIC &&
+ !selabel_partial_match(fc_sehandle,
+ ftsent->fts_path)) {
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ }
+
+ if (check_excluded(ftsent->fts_path)) {
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ }
+
+ if (state->setrestorecondigest) {
+ struct dir_hash_node *new_node = NULL;
+
+ if (check_context_match_for_dir(ftsent->fts_path,
+ &new_node,
+ state->error) &&
+ !state->ignore_digest) {
+ selinux_log_sync(SELINUX_INFO,
+ "Skipping restorecon on directory(%s)\n",
+ ftsent->fts_path);
+ fts_set(fts, ftsent, FTS_SKIP);
+ continue;
+ }
+
+ if (new_node && !state->error) {
+ if (!state->current) {
+ state->current = new_node;
+ state->head = state->current;
+ } else {
+ state->current->next = new_node;
+ state->current = new_node;
+ }
+ }
+ }
+ /* fall through */
+ default:
+ strcpy(ent_path, ftsent->fts_path);
+ ent_st = *ftsent->fts_statp;
+ if (state->parallel) {
+ state->inprogress += 1;
+ pthread_mutex_unlock(&state->mutex);
+ }
+
+ error = restorecon_sb(ent_path, &ent_st, &state->flags,
+ first);
+
+ if (state->parallel) {
+ pthread_mutex_lock(&state->mutex);
+ state->inprogress -= 1;
+ if (state->abort)
+ goto unlock;
+ }
+
+ state->error |= error;
+ first = false;
+ if (error && state->flags.abort_on_error) {
+ state->abort = true;
+ goto finish;
+ }
+ break;
+ }
+ }
+
+finish:
+ if (!state->saved_errno)
+ state->saved_errno = errno;
+unlock:
+ if (state->parallel) {
+ if (state->inprogress == 0)
+ pthread_cond_signal(&state->cond_finish);
+ pthread_mutex_unlock(&state->mutex);
+ }
+ return NULL;
+}
+
+static int selinux_restorecon_common(const char *pathname_orig,
+ unsigned int restorecon_flags,
+ size_t nthreads)
+{
+ struct rest_state state;
- flags.nochange = (restorecon_flags &
+ state.flags.nochange = (restorecon_flags &
SELINUX_RESTORECON_NOCHANGE) ? true : false;
- flags.verbose = (restorecon_flags &
+ state.flags.verbose = (restorecon_flags &
SELINUX_RESTORECON_VERBOSE) ? true : false;
- flags.progress = (restorecon_flags &
+ state.flags.progress = (restorecon_flags &
SELINUX_RESTORECON_PROGRESS) ? true : false;
- flags.mass_relabel = (restorecon_flags &
+ state.flags.mass_relabel = (restorecon_flags &
SELINUX_RESTORECON_MASS_RELABEL) ? true : false;
- flags.recurse = (restorecon_flags &
+ state.flags.recurse = (restorecon_flags &
SELINUX_RESTORECON_RECURSE) ? true : false;
- flags.set_specctx = (restorecon_flags &
+ state.flags.set_specctx = (restorecon_flags &
SELINUX_RESTORECON_SET_SPECFILE_CTX) ? true : false;
- flags.userealpath = (restorecon_flags &
+ state.flags.userealpath = (restorecon_flags &
SELINUX_RESTORECON_REALPATH) ? true : false;
- flags.set_xdev = (restorecon_flags &
+ state.flags.set_xdev = (restorecon_flags &
SELINUX_RESTORECON_XDEV) ? true : false;
- flags.add_assoc = (restorecon_flags &
+ state.flags.add_assoc = (restorecon_flags &
SELINUX_RESTORECON_ADD_ASSOC) ? true : false;
- flags.abort_on_error = (restorecon_flags &
+ state.flags.abort_on_error = (restorecon_flags &
SELINUX_RESTORECON_ABORT_ON_ERROR) ? true : false;
- flags.syslog_changes = (restorecon_flags &
+ state.flags.syslog_changes = (restorecon_flags &
SELINUX_RESTORECON_SYSLOG_CHANGES) ? true : false;
- flags.log_matches = (restorecon_flags &
+ state.flags.log_matches = (restorecon_flags &
SELINUX_RESTORECON_LOG_MATCHES) ? true : false;
- flags.ignore_noent = (restorecon_flags &
+ state.flags.ignore_noent = (restorecon_flags &
SELINUX_RESTORECON_IGNORE_NOENTRY) ? true : false;
- flags.warnonnomatch = true;
- flags.conflicterror = (restorecon_flags &
+ state.flags.warnonnomatch = true;
+ state.flags.conflicterror = (restorecon_flags &
SELINUX_RESTORECON_CONFLICT_ERROR) ? true : false;
ignore_mounts = (restorecon_flags &
SELINUX_RESTORECON_IGNORE_MOUNTS) ? true : false;
- bool ignore_digest = (restorecon_flags &
+ state.ignore_digest = (restorecon_flags &
SELINUX_RESTORECON_IGNORE_DIGEST) ? true : false;
- bool setrestorecondigest = true;
+ state.setrestorecondigest = true;
+
+ state.head = NULL;
+ state.current = NULL;
+ state.abort = false;
+ state.error = 0;
+ state.saved_errno = 0;
struct stat sb;
- struct statfs sfsb;
- FTS *fts;
- FTSENT *ftsent;
char *pathname = NULL, *pathdnamer = NULL, *pathdname, *pathbname;
char *paths[2] = { NULL, NULL };
int fts_flags, error, sverrno;
- dev_t dev_num = 0;
struct dir_hash_node *current = NULL;
- struct dir_hash_node *head = NULL;
- if (flags.verbose && flags.progress)
- flags.verbose = false;
+ if (state.flags.verbose && state.flags.progress)
+ state.flags.verbose = false;
__selinux_once(fc_once, restorecon_init);
@@ -896,13 +1048,31 @@ int selinux_restorecon(const char *pathname_orig,
*/
if (selabel_no_digest ||
(restorecon_flags & SELINUX_RESTORECON_SKIP_DIGEST))
- setrestorecondigest = false;
+ state.setrestorecondigest = false;
+
+ if (!__pthread_supported) {
+ if (nthreads != 1) {
+ nthreads = 1;
+ selinux_log(SELINUX_WARNING,
+ "Threading functionality not available, falling back to 1 thread.");
+ }
+ } else if (nthreads == 0) {
+ long nproc = sysconf(_SC_NPROCESSORS_ONLN);
+
+ if (nproc > 0) {
+ nthreads = nproc;
+ } else {
+ nthreads = 1;
+ selinux_log(SELINUX_WARNING,
+ "Unable to detect CPU count, falling back to 1 thread.");
+ }
+ }
/*
* Convert passed-in pathname to canonical pathname by resolving
* realpath of containing dir, then appending last component name.
*/
- if (flags.userealpath) {
+ if (state.flags.userealpath) {
char *basename_cpy = strdup(pathname_orig);
if (!basename_cpy)
goto realpatherr;
@@ -947,7 +1117,7 @@ int selinux_restorecon(const char *pathname_orig,
paths[0] = pathname;
if (lstat(pathname, &sb) < 0) {
- if (flags.ignore_noent && errno == ENOENT) {
+ if (state.flags.ignore_noent && errno == ENOENT) {
free(pathdnamer);
free(pathname);
return 0;
@@ -962,21 +1132,21 @@ int selinux_restorecon(const char *pathname_orig,
/* Skip digest if not a directory */
if (!S_ISDIR(sb.st_mode))
- setrestorecondigest = false;
+ state.setrestorecondigest = false;
- if (!flags.recurse) {
+ if (!state.flags.recurse) {
if (check_excluded(pathname)) {
error = 0;
goto cleanup;
}
- error = restorecon_sb(pathname, &sb, &flags);
+ error = restorecon_sb(pathname, &sb, &state.flags, true);
goto cleanup;
}
/* Obtain fs type */
- memset(&sfsb, 0, sizeof sfsb);
- if (!S_ISLNK(sb.st_mode) && statfs(pathname, &sfsb) < 0) {
+ memset(&state.sfsb, 0, sizeof(state.sfsb));
+ if (!S_ISLNK(sb.st_mode) && statfs(pathname, &state.sfsb) < 0) {
selinux_log(SELINUX_ERROR,
"statfs(%s) failed: %s\n",
pathname, strerror(errno));
@@ -985,21 +1155,21 @@ int selinux_restorecon(const char *pathname_orig,
}
/* Skip digest on in-memory filesystems and /sys */
- if (sfsb.f_type == RAMFS_MAGIC || sfsb.f_type == TMPFS_MAGIC ||
- sfsb.f_type == SYSFS_MAGIC)
- setrestorecondigest = false;
+ if (state.sfsb.f_type == RAMFS_MAGIC || state.sfsb.f_type == TMPFS_MAGIC ||
+ state.sfsb.f_type == SYSFS_MAGIC)
+ state.setrestorecondigest = false;
- if (flags.set_xdev)
+ if (state.flags.set_xdev)
fts_flags = FTS_PHYSICAL | FTS_NOCHDIR | FTS_XDEV;
else
fts_flags = FTS_PHYSICAL | FTS_NOCHDIR;
- fts = fts_open(paths, fts_flags, NULL);
- if (!fts)
+ state.fts = fts_open(paths, fts_flags, NULL);
+ if (!state.fts)
goto fts_err;
- ftsent = fts_read(fts);
- if (!ftsent)
+ state.ftsent_first = fts_read(state.fts);
+ if (!state.ftsent_first)
goto fts_err;
/*
@@ -1011,100 +1181,54 @@ int selinux_restorecon(const char *pathname_orig,
* directories with a different device number when the FTS_XDEV flag
* is set (from http://marc.info/?l=selinux&m=124688830500777&w=2).
*/
- dev_num = ftsent->fts_statp->st_dev;
+ state.dev_num = state.ftsent_first->fts_statp->st_dev;
- error = 0;
- do {
- /* If the FTS_XDEV flag is set and the device is different */
- if (flags.set_xdev && ftsent->fts_statp->st_dev != dev_num)
- continue;
-
- switch (ftsent->fts_info) {
- case FTS_DC:
- selinux_log(SELINUX_ERROR,
- "Directory cycle on %s.\n",
- ftsent->fts_path);
- errno = ELOOP;
- error = -1;
- goto out;
- case FTS_DP:
- continue;
- case FTS_DNR:
- selinux_log(SELINUX_ERROR,
- "Could not read %s: %s.\n",
- ftsent->fts_path,
- strerror(ftsent->fts_errno));
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- case FTS_NS:
- selinux_log(SELINUX_ERROR,
- "Could not stat %s: %s.\n",
- ftsent->fts_path,
- strerror(ftsent->fts_errno));
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- case FTS_ERR:
- selinux_log(SELINUX_ERROR,
- "Error on %s: %s.\n",
- ftsent->fts_path,
- strerror(ftsent->fts_errno));
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- case FTS_D:
- if (sfsb.f_type == SYSFS_MAGIC &&
- !selabel_partial_match(fc_sehandle,
- ftsent->fts_path)) {
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- }
+ if (nthreads == 1) {
+ state.parallel = false;
+ selinux_restorecon_thread(&state);
+ } else {
+ size_t i;
+ pthread_t thread;
+
+ pthread_mutex_init(&state.mutex, NULL);
+ pthread_cond_init(&state.cond_finish, NULL);
+
+ state.parallel = true;
+ /*
+ * Start (nthreads - 1) threads - this thread is going to
+ * take part, too.
+ */
+ for (i = 1; i < nthreads; i++) {
+ pthread_create(&thread, NULL, selinux_restorecon_thread,
+ &state);
+ /*
+ * If thread creation failed - doesn't matter, we just
+ * let the successfully created threads do the job.
+ */
+ }
- if (check_excluded(ftsent->fts_path)) {
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- }
+ /* Let's join in on the fun! */
+ selinux_restorecon_thread(&state);
- if (setrestorecondigest) {
- struct dir_hash_node *new_node = NULL;
+ pthread_mutex_lock(&state.mutex);
+ if (state.inprogress != 0)
+ pthread_cond_wait(&state.cond_finish, &state.mutex);
+ pthread_mutex_unlock(&state.mutex);
- if (check_context_match_for_dir(ftsent->fts_path,
- &new_node,
- error) &&
- !ignore_digest) {
- selinux_log(SELINUX_INFO,
- "Skipping restorecon on directory(%s)\n",
- ftsent->fts_path);
- fts_set(fts, ftsent, FTS_SKIP);
- continue;
- }
+ pthread_mutex_destroy(&state.mutex);
+ pthread_cond_destroy(&state.cond_finish);
+ }
- if (new_node && !error) {
- if (!current) {
- current = new_node;
- head = current;
- } else {
- current->next = new_node;
- current = current->next;
- }
- }
- }
- /* fall through */
- default:
- error |= restorecon_sb(ftsent->fts_path,
- ftsent->fts_statp, &flags);
- if (flags.warnonnomatch)
- flags.warnonnomatch = false;
- if (error && flags.abort_on_error)
- goto out;
- break;
- }
- } while ((ftsent = fts_read(fts)) != NULL);
+ error = state.error;
+ if (state.saved_errno)
+ goto out;
/*
* Labeling successful. Write partial match digests for subdirectories.
* TODO: Write digest upon FTS_DP if no error occurs in its descents.
*/
- if (setrestorecondigest && !flags.nochange && !error) {
- current = head;
+ if (state.setrestorecondigest && !state.flags.nochange && !error) {
+ current = state.head;
while (current != NULL) {
if (setxattr(current->path,
RESTORECON_PARTIAL_MATCH_DIGEST,
@@ -1120,22 +1244,21 @@ int selinux_restorecon(const char *pathname_orig,
}
out:
- if (flags.progress && flags.mass_relabel)
+ if (state.flags.progress && state.flags.mass_relabel)
fprintf(stdout, "\r%s 100.0%%\n", pathname);
- sverrno = errno;
- (void) fts_close(fts);
- errno = sverrno;
+ (void) fts_close(state.fts);
+ errno = state.saved_errno;
cleanup:
- if (flags.add_assoc) {
- if (flags.verbose)
+ if (state.flags.add_assoc) {
+ if (state.flags.verbose)
filespec_eval();
filespec_destroy();
}
free(pathdnamer);
free(pathname);
- current = head;
+ current = state.head;
while (current != NULL) {
struct dir_hash_node *next = current->next;
@@ -1169,6 +1292,26 @@ fts_err:
goto cleanup;
}
+
+/*
+ * Public API
+ */
+
+/* selinux_restorecon(3) - Main function that is responsible for labeling */
+int selinux_restorecon(const char *pathname_orig,
+ unsigned int restorecon_flags)
+{
+ return selinux_restorecon_common(pathname_orig, restorecon_flags, 1);
+}
+
+/* selinux_restorecon_parallel(3) - Parallel version of selinux_restorecon(3) */
+int selinux_restorecon_parallel(const char *pathname_orig,
+ unsigned int restorecon_flags,
+ size_t nthreads)
+{
+ return selinux_restorecon_common(pathname_orig, restorecon_flags, nthreads);
+}
+
/* selinux_restorecon_set_sehandle(3) is called to set the global fc handle */
void selinux_restorecon_set_sehandle(struct selabel_handle *hndl)
{
--
2.30.2
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [RFC PATCH userspace 6/6] setfiles/restorecon: support parallel relabeling
2021-03-23 17:08 [RFC PATCH userspace 0/6] Parallel setfiles/restorecon Ondrej Mosnacek
` (4 preceding siblings ...)
2021-03-23 17:08 ` [RFC PATCH userspace 5/6] selinux_restorecon: introduce selinux_restorecon_parallel(3) Ondrej Mosnacek
@ 2021-03-23 17:08 ` Ondrej Mosnacek
2021-03-24 9:58 ` [RFC PATCH userspace 0/6] Parallel setfiles/restorecon peter enderborg
6 siblings, 0 replies; 11+ messages in thread
From: Ondrej Mosnacek @ 2021-03-23 17:08 UTC (permalink / raw)
To: selinux
Use the newly introduced selinux_restorecon_parallel(3) in
setfiles/restorecon and a -T option to both to allow enabling parallel
relabeling. The default behavior without specifying the -T option is to
use 1 thread; parallel relabeling must be requested explicitly by
passing -T 0 (which will use as many threads as there are available CPU
cores) or -T <N>, which will use <N> threads.
=== Benchmarks ===
As measured on a 32-core cloud VM with Fedora 34. Not a fully
representative environment, but still the scaling is quite good.
WITHOUT PATCHES:
$ time restorecon -rn /usr/src
real 0m23,580s
user 0m22,681s
sys 0m0,707s
WITH PATCHES:
$ time restorecon -rn -T 1 /usr/src
real 0m23,493s
user 0m22,637s
sys 0m0,668s
$ time restorecon -rn -T 2 /usr/src
real 0m13,438s
user 0m25,536s
sys 0m0,946s
$ time restorecon -rn -T 8 /usr/src
real 0m5,476s
user 0m38,440s
sys 0m3,016s
$ time restorecon -rn -T 16 /usr/src
real 0m3,868s
user 0m51,292s
sys 0m5,289s
$ time restorecon -rn -T 32 /usr/src
real 0m2,817s
user 1m0,317s
sys 0m6,157s
Note that the benchmarks were performed in read-only mode (-n), so the
labels were only read and looked up in the database, not written. When
fixing labels on a heavily mislabeled system, the scaling would likely
be event better, since a larger % of work could be done in parallel.
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
---
policycoreutils/setfiles/Makefile | 2 +-
policycoreutils/setfiles/restore.c | 7 ++++---
policycoreutils/setfiles/restore.h | 2 +-
policycoreutils/setfiles/restorecon.8 | 9 +++++++++
policycoreutils/setfiles/setfiles.8 | 9 +++++++++
policycoreutils/setfiles/setfiles.c | 28 ++++++++++++++++-----------
6 files changed, 41 insertions(+), 16 deletions(-)
diff --git a/policycoreutils/setfiles/Makefile b/policycoreutils/setfiles/Makefile
index a3bbbe11..82de8f2a 100644
--- a/policycoreutils/setfiles/Makefile
+++ b/policycoreutils/setfiles/Makefile
@@ -6,7 +6,7 @@ MANDIR = $(PREFIX)/share/man
AUDITH ?= $(shell test -f /usr/include/libaudit.h && echo y)
CFLAGS ?= -g -Werror -Wall -W
-override LDLIBS += -lselinux -lsepol
+override LDLIBS += -lselinux -lsepol -lpthread
ifeq ($(AUDITH), y)
override CFLAGS += -DUSE_AUDIT
diff --git a/policycoreutils/setfiles/restore.c b/policycoreutils/setfiles/restore.c
index 9d688c60..74d48bb3 100644
--- a/policycoreutils/setfiles/restore.c
+++ b/policycoreutils/setfiles/restore.c
@@ -72,7 +72,7 @@ void restore_finish(void)
}
}
-int process_glob(char *name, struct restore_opts *opts)
+int process_glob(char *name, struct restore_opts *opts, size_t nthreads)
{
glob_t globbuf;
size_t i = 0;
@@ -91,8 +91,9 @@ int process_glob(char *name, struct restore_opts *opts)
continue;
if (len > 0 && strcmp(&globbuf.gl_pathv[i][len], "/..") == 0)
continue;
- rc = selinux_restorecon(globbuf.gl_pathv[i],
- opts->restorecon_flags);
+ rc = selinux_restorecon_parallel(globbuf.gl_pathv[i],
+ opts->restorecon_flags,
+ nthreads);
if (rc < 0)
errors = rc;
}
diff --git a/policycoreutils/setfiles/restore.h b/policycoreutils/setfiles/restore.h
index ac6ad680..bb35a1db 100644
--- a/policycoreutils/setfiles/restore.h
+++ b/policycoreutils/setfiles/restore.h
@@ -49,7 +49,7 @@ struct restore_opts {
void restore_init(struct restore_opts *opts);
void restore_finish(void);
void add_exclude(const char *directory);
-int process_glob(char *name, struct restore_opts *opts);
+int process_glob(char *name, struct restore_opts *opts, size_t nthreads);
extern char **exclude_list;
#endif
diff --git a/policycoreutils/setfiles/restorecon.8 b/policycoreutils/setfiles/restorecon.8
index 668486f6..e07db2c8 100644
--- a/policycoreutils/setfiles/restorecon.8
+++ b/policycoreutils/setfiles/restorecon.8
@@ -33,6 +33,8 @@ restorecon \- restore file(s) default SELinux security contexts.
.RB [ \-W ]
.RB [ \-I | \-D ]
.RB [ \-x ]
+.RB [ \-T
+.IR nthreads ]
.SH "DESCRIPTION"
This manual page describes the
@@ -160,6 +162,13 @@ prevent
.B restorecon
from crossing file system boundaries.
.TP
+.BI \-T \ nthreads
+use up to
+.I nthreads
+threads. Specify 0 to create as many threads as there are available
+CPU cores; 1 to use only a single thread (default); or any positive
+number to use the given number of threads (if possible).
+.TP
.SH "ARGUMENTS"
.IR pathname \ ...
The pathname for the file(s) to be relabeled.
diff --git a/policycoreutils/setfiles/setfiles.8 b/policycoreutils/setfiles/setfiles.8
index 4d28bc9a..15f939d1 100644
--- a/policycoreutils/setfiles/setfiles.8
+++ b/policycoreutils/setfiles/setfiles.8
@@ -19,6 +19,8 @@ setfiles \- set SELinux file security contexts.
.RB [ \-W ]
.RB [ \-F ]
.RB [ \-I | \-D ]
+.RB [ \-T
+.IR nthreads ]
.I spec_file
.IR pathname \ ...
@@ -161,6 +163,13 @@ quote marks or backslashes. The
option of GNU
.B find
produces input suitable for this mode.
+.TP
+.BI \-T \ nthreads
+use up to
+.I nthreads
+threads. Specify 0 to create as many threads as there are available
+CPU cores; 1 to use only a single thread (default); or any positive
+number to use the given number of threads (if possible).
.SH "ARGUMENTS"
.TP
diff --git a/policycoreutils/setfiles/setfiles.c b/policycoreutils/setfiles/setfiles.c
index f018d161..2313a21f 100644
--- a/policycoreutils/setfiles/setfiles.c
+++ b/policycoreutils/setfiles/setfiles.c
@@ -1,4 +1,5 @@
#include "restore.h"
+#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio_ext.h>
@@ -34,14 +35,14 @@ static __attribute__((__noreturn__)) void usage(const char *const name)
{
if (iamrestorecon) {
fprintf(stderr,
- "usage: %s [-iIDFmnprRv0x] [-e excludedir] pathname...\n"
- "usage: %s [-iIDFmnprRv0x] [-e excludedir] -f filename\n",
+ "usage: %s [-iIDFmnprRv0xT] [-e excludedir] pathname...\n"
+ "usage: %s [-iIDFmnprRv0xT] [-e excludedir] -f filename\n",
name, name);
} else {
fprintf(stderr,
- "usage: %s [-diIDlmnpqvEFW] [-e excludedir] [-r alt_root_path] [-c policyfile] spec_file pathname...\n"
- "usage: %s [-diIDlmnpqvEFW] [-e excludedir] [-r alt_root_path] [-c policyfile] spec_file -f filename\n"
- "usage: %s -s [-diIDlmnpqvFW] spec_file\n",
+ "usage: %s [-diIDlmnpqvEFWT] [-e excludedir] [-r alt_root_path] [-c policyfile] spec_file pathname...\n"
+ "usage: %s [-diIDlmnpqvEFWT] [-e excludedir] [-r alt_root_path] [-c policyfile] spec_file -f filename\n"
+ "usage: %s -s [-diIDlmnpqvFWT] spec_file\n",
name, name, name);
}
exit(-1);
@@ -144,12 +145,12 @@ int main(int argc, char **argv)
int opt, i = 0;
const char *input_filename = NULL;
int use_input_file = 0;
- char *buf = NULL;
- size_t buf_len;
+ char *buf = NULL, *endptr;
+ size_t buf_len, nthreads = 1;
const char *base;
int errors = 0;
- const char *ropts = "e:f:hiIDlmno:pqrsvFRW0x";
- const char *sopts = "c:de:f:hiIDlmno:pqr:svEFR:W0";
+ const char *ropts = "e:f:hiIDlmno:pqrsvFRW0xT:";
+ const char *sopts = "c:de:f:hiIDlmno:pqr:svEFR:W0T:";
const char *opts;
union selinux_callback cb;
@@ -370,6 +371,11 @@ int main(int argc, char **argv)
usage(argv[0]);
}
break;
+ case 'T':
+ nthreads = strtoull(optarg, &endptr, 10);
+ if (*optarg == '\0' || *endptr != '\0')
+ usage(argv[0]);
+ break;
case 'h':
case '?':
usage(argv[0]);
@@ -448,13 +454,13 @@ int main(int argc, char **argv)
buf[len - 1] = 0;
if (!strcmp(buf, "/"))
r_opts.mass_relabel = SELINUX_RESTORECON_MASS_RELABEL;
- errors |= process_glob(buf, &r_opts) < 0;
+ errors |= process_glob(buf, &r_opts, nthreads) < 0;
}
if (strcmp(input_filename, "-") != 0)
fclose(f);
} else {
for (i = optind; i < argc; i++)
- errors |= process_glob(argv[i], &r_opts) < 0;
+ errors |= process_glob(argv[i], &r_opts, nthreads) < 0;
}
maybe_audit_mass_relabel(r_opts.mass_relabel, errors);
--
2.30.2
^ permalink raw reply related [flat|nested] 11+ messages in thread