[PATCH 22/29] powerpc: use non-racy method for proc entries creation

["Denis V. Lunev" <den@openvz.org>]

Use proc_create()/proc_create_data() to make sure that ->proc_fops and
->data be setup before gluing PDE to main tree.

Add correct ->owner to proc_fops to fix reading/module unloading race.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Paul Mackerras <paulus@samba.org>
CC: linuxppc-dev@ozlabs.org
---
 arch/powerpc/kernel/lparcfg.c                |    6 +--
 arch/powerpc/kernel/proc_ppc64.c             |    5 +--
 arch/powerpc/kernel/rtas-proc.c              |   45 ++++++++------------------
 arch/powerpc/kernel/rtas_flash.c             |   13 ++-----
 arch/powerpc/platforms/cell/spufs/sched.c    |    3 +-
 arch/powerpc/platforms/cell/spufs/sputrace.c |    3 +-
 arch/powerpc/platforms/iseries/lpevents.c    |    8 +---
 arch/powerpc/platforms/iseries/mf.c          |    6 ++--
 arch/powerpc/platforms/iseries/proc.c        |    8 +---
 arch/powerpc/platforms/iseries/viopath.c     |    7 +---
 arch/powerpc/platforms/pseries/eeh.c         |   10 +----
 arch/powerpc/platforms/pseries/reconfig.c    |    7 +---
 arch/powerpc/platforms/pseries/rtasd.c       |    7 ++--
 13 files changed, 39 insertions(+), 89 deletions(-)

diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 1ffacc6..1e656b4 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -591,10 +591,8 @@ int __init lparcfg_init(void)
 			!firmware_has_feature(FW_FEATURE_ISERIES))
 		mode |= S_IWUSR;
 
-	ent = create_proc_entry("ppc64/lparcfg", mode, NULL);
-	if (ent) {
-		ent->proc_fops = &lparcfg_fops;
-	} else {
+	ent = proc_create("ppc64/lparcfg", mode, NULL, &lparcfg_fops);
+	if (!ent) {
 		printk(KERN_ERR "Failed to create ppc64/lparcfg\n");
 		return -EIO;
 	}
diff --git a/arch/powerpc/kernel/proc_ppc64.c b/arch/powerpc/kernel/proc_ppc64.c
index f78dfce..c647dde 100644
--- a/arch/powerpc/kernel/proc_ppc64.c
+++ b/arch/powerpc/kernel/proc_ppc64.c
@@ -68,12 +68,11 @@ static int __init proc_ppc64_init(void)
 {
 	struct proc_dir_entry *pde;
 
-	pde = create_proc_entry("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL);
+	pde = proc_create_data("ppc64/systemcfg", S_IFREG|S_IRUGO, NULL,
+			       &page_map_fops, vdso_data);
 	if (!pde)
 		return 1;
-	pde->data = vdso_data;
 	pde->size = PAGE_SIZE;
-	pde->proc_fops = &page_map_fops;
 
 	return 0;
 }
diff --git a/arch/powerpc/kernel/rtas-proc.c b/arch/powerpc/kernel/rtas-proc.c
index f2e3bc7..f9c6abc 100644
--- a/arch/powerpc/kernel/rtas-proc.c
+++ b/arch/powerpc/kernel/rtas-proc.c
@@ -255,8 +255,6 @@ static void check_location(struct seq_file *m, const char *c);
 
 static int __init proc_rtas_init(void)
 {
-	struct proc_dir_entry *entry;
-
 	if (!machine_is(pseries))
 		return -ENODEV;
 
@@ -264,35 +262,20 @@ static int __init proc_rtas_init(void)
 	if (rtas_node == NULL)
 		return -ENODEV;
 
-	entry = create_proc_entry("ppc64/rtas/progress", S_IRUGO|S_IWUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_progress_operations;
-
-	entry = create_proc_entry("ppc64/rtas/clock", S_IRUGO|S_IWUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_clock_operations;
-
-	entry = create_proc_entry("ppc64/rtas/poweron", S_IWUSR|S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_poweron_operations;
-
-	entry = create_proc_entry("ppc64/rtas/sensors", S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_sensors_operations;
-
-	entry = create_proc_entry("ppc64/rtas/frequency", S_IWUSR|S_IRUGO,
-				  NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_tone_freq_operations;
-
-	entry = create_proc_entry("ppc64/rtas/volume", S_IWUSR|S_IRUGO, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_tone_volume_operations;
-
-	entry = create_proc_entry("ppc64/rtas/rmo_buffer", S_IRUSR, NULL);
-	if (entry)
-		entry->proc_fops = &ppc_rtas_rmo_buf_ops;
-
+	proc_create("ppc64/rtas/progress", S_IRUGO|S_IWUSR, NULL,
+		    &ppc_rtas_progress_operations);
+	proc_create("ppc64/rtas/clock", S_IRUGO|S_IWUSR, NULL,
+		    &ppc_rtas_clock_operations);
+	proc_create("ppc64/rtas/poweron", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_poweron_operations);
+	proc_create("ppc64/rtas/sensors", S_IRUGO, NULL,
+		    &ppc_rtas_sensors_operations);
+	proc_create("ppc64/rtas/frequency", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_tone_freq_operations);
+	proc_create("ppc64/rtas/volume", S_IWUSR|S_IRUGO, NULL,
+		    &ppc_rtas_tone_volume_operations);
+	proc_create("ppc64/rtas/rmo_buffer", S_IRUSR, NULL,
+		    &ppc_rtas_rmo_buf_ops);
 	return 0;
 }
 
diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c
index e1756e1..d32bfe4 100644
--- a/arch/powerpc/kernel/rtas_flash.c
+++ b/arch/powerpc/kernel/rtas_flash.c
@@ -704,18 +704,11 @@ static int initialize_flash_pde_data(const char *rtas_call_name,
 static struct proc_dir_entry *create_flash_pde(const char *filename,
 					       const struct file_operations *fops)
 {
-	struct proc_dir_entry *ent = NULL;
-
-	ent = create_proc_entry(filename, S_IRUSR | S_IWUSR, NULL);
-	if (ent != NULL) {
-		ent->proc_fops = fops;
-		ent->owner = THIS_MODULE;
-	}
-
-	return ent;
+	return proc_create(filename, S_IRUSR | S_IWUSR, NULL, fops);
 }
 
 static const struct file_operations rtas_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= rtas_flash_read,
 	.write		= rtas_flash_write,
 	.open		= rtas_excl_open,
@@ -723,6 +716,7 @@ static const struct file_operations rtas_flash_operations = {
 };
 
 static const struct file_operations manage_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= manage_flash_read,
 	.write		= manage_flash_write,
 	.open		= rtas_excl_open,
@@ -730,6 +724,7 @@ static const struct file_operations manage_flash_operations = {
 };
 
 static const struct file_operations validate_flash_operations = {
+	.owner		= THIS_MODULE,
 	.read		= validate_flash_read,
 	.write		= validate_flash_write,
 	.open		= rtas_excl_open,
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 00528ef..45dcd26 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -1063,10 +1063,9 @@ int __init spu_sched_init(void)
 
 	mod_timer(&spuloadavg_timer, 0);
 
-	entry = create_proc_entry("spu_loadavg", 0, NULL);
+	entry = proc_create("spu_loadavg", 0, NULL, &spu_loadavg_fops);
 	if (!entry)
 		goto out_stop_kthread;
-	entry->proc_fops = &spu_loadavg_fops;
 
 	pr_debug("spusched: tick: %d, min ticks: %d, default ticks: %d\n",
 			SPUSCHED_TICK, MIN_SPU_TIMESLICE, DEF_SPU_TIMESLICE);
diff --git a/arch/powerpc/platforms/cell/spufs/sputrace.c b/arch/powerpc/platforms/cell/spufs/sputrace.c
index 79aa773..aea5286 100644
--- a/arch/powerpc/platforms/cell/spufs/sputrace.c
+++ b/arch/powerpc/platforms/cell/spufs/sputrace.c
@@ -201,10 +201,9 @@ static int __init sputrace_init(void)
 	if (!sputrace_log)
 		goto out;
 
-	entry = create_proc_entry("sputrace", S_IRUSR, NULL);
+	entry = proc_create("sputrace", S_IRUSR, NULL, &sputrace_fops);
 	if (!entry)
 		goto out_free_log;
-	entry->proc_fops = &sputrace_fops;
 
 	for (i = 0; i < ARRAY_SIZE(spu_probes); i++) {
 		struct spu_probe *p = &spu_probes[i];
diff --git a/arch/powerpc/platforms/iseries/lpevents.c b/arch/powerpc/platforms/iseries/lpevents.c
index e5b40e3..b0f8a85 100644
--- a/arch/powerpc/platforms/iseries/lpevents.c
+++ b/arch/powerpc/platforms/iseries/lpevents.c
@@ -330,15 +330,11 @@ static const struct file_operations proc_lpevents_operations = {
 
 static int __init proc_lpevents_init(void)
 {
-	struct proc_dir_entry *e;
-
 	if (!firmware_has_feature(FW_FEATURE_ISERIES))
 		return 0;
 
-	e = create_proc_entry("iSeries/lpevents", S_IFREG|S_IRUGO, NULL);
-	if (e)
-		e->proc_fops = &proc_lpevents_operations;
-
+	proc_create("iSeries/lpevents", S_IFREG|S_IRUGO, NULL,
+		    &proc_lpevents_operations);
 	return 0;
 }
 __initcall(proc_lpevents_init);
diff --git a/arch/powerpc/platforms/iseries/mf.c b/arch/powerpc/platforms/iseries/mf.c
index c0f2433..1dc7295 100644
--- a/arch/powerpc/platforms/iseries/mf.c
+++ b/arch/powerpc/platforms/iseries/mf.c
@@ -1255,11 +1255,11 @@ static int __init mf_proc_init(void)
 		if (i == 3)	/* no vmlinux entry for 'D' */
 			continue;
 
-		ent = create_proc_entry("vmlinux", S_IFREG|S_IWUSR, mf);
+		ent = proc_create_data("vmlinux", S_IFREG|S_IWUSR, mf,
+				       &proc_vmlinux_operations,
+				       (void *)(long)i);
 		if (!ent)
 			return 1;
-		ent->data = (void *)(long)i;
-		ent->proc_fops = &proc_vmlinux_operations;
 	}
 
 	ent = create_proc_entry("side", S_IFREG|S_IRUSR|S_IWUSR, mf_proc_root);
diff --git a/arch/powerpc/platforms/iseries/proc.c b/arch/powerpc/platforms/iseries/proc.c
index f2cde41..91f4c6c 100644
--- a/arch/powerpc/platforms/iseries/proc.c
+++ b/arch/powerpc/platforms/iseries/proc.c
@@ -110,15 +110,11 @@ static const struct file_operations proc_titantod_operations = {
 
 static int __init iseries_proc_init(void)
 {
-	struct proc_dir_entry *e;
-
 	if (!firmware_has_feature(FW_FEATURE_ISERIES))
 		return 0;
 
-	e = create_proc_entry("iSeries/titanTod", S_IFREG|S_IRUGO, NULL);
-	if (e)
-		e->proc_fops = &proc_titantod_operations;
-
+	proc_create("iSeries/titanTod", S_IFREG|S_IRUGO, NULL,
+		    &proc_titantod_operations);
 	return 0;
 }
 __initcall(iseries_proc_init);
diff --git a/arch/powerpc/platforms/iseries/viopath.c b/arch/powerpc/platforms/iseries/viopath.c
index df23331..49ff4dc 100644
--- a/arch/powerpc/platforms/iseries/viopath.c
+++ b/arch/powerpc/platforms/iseries/viopath.c
@@ -180,15 +180,10 @@ static const struct file_operations proc_viopath_operations = {
 
 static int __init vio_proc_init(void)
 {
-	struct proc_dir_entry *e;
-
 	if (!firmware_has_feature(FW_FEATURE_ISERIES))
 		return 0;
 
-	e = create_proc_entry("iSeries/config", 0, NULL);
-	if (e)
-		e->proc_fops = &proc_viopath_operations;
-
+	proc_create("iSeries/config", 0, NULL, &proc_viopath_operations);
         return 0;
 }
 __initcall(vio_proc_init);
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c
index 9eb539e..d6df95b 100644
--- a/arch/powerpc/platforms/pseries/eeh.c
+++ b/arch/powerpc/platforms/pseries/eeh.c
@@ -1261,14 +1261,8 @@ static const struct file_operations proc_eeh_operations = {
 
 static int __init eeh_init_proc(void)
 {
-	struct proc_dir_entry *e;
-
-	if (machine_is(pseries)) {
-		e = create_proc_entry("ppc64/eeh", 0, NULL);
-		if (e)
-			e->proc_fops = &proc_eeh_operations;
-	}
-
+	if (machine_is(pseries))
+		proc_create("ppc64/eeh", 0, NULL, &proc_eeh_operations);
 	return 0;
 }
 __initcall(eeh_init_proc);
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index ac75c10..75769aa 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -512,12 +512,9 @@ static int proc_ppc64_create_ofdt(void)
 	if (!machine_is(pseries))
 		return 0;
 
-	ent = create_proc_entry("ppc64/ofdt", S_IWUSR, NULL);
-	if (ent) {
-		ent->data = NULL;
+	ent = proc_create("ppc64/ofdt", S_IWUSR, NULL, &ofdt_fops);
+	if (ent)
 		ent->size = 0;
-		ent->proc_fops = &ofdt_fops;
-	}
 
 	return 0;
 }
diff --git a/arch/powerpc/platforms/pseries/rtasd.c b/arch/powerpc/platforms/pseries/rtasd.c
index e3078ce..bc2883c 100644
--- a/arch/powerpc/platforms/pseries/rtasd.c
+++ b/arch/powerpc/platforms/pseries/rtasd.c
@@ -472,10 +472,9 @@ static int __init rtas_init(void)
 		return -ENOMEM;
 	}
 
-	entry = create_proc_entry("ppc64/rtas/error_log", S_IRUSR, NULL);
-	if (entry)
-		entry->proc_fops = &proc_rtas_log_operations;
-	else
+	entry = proc_create("ppc64/rtas/error_log", S_IRUSR, NULL,
+			    &proc_rtas_log_operations);
+	if (!entry)
 		printk(KERN_ERR "Failed to create error_log proc entry\n");
 
 	if (kernel_thread(rtasd, NULL, CLONE_FS) < 0)
-- 
1.5.3.rc5