[PATCH] sn2: use static ->proc_fops

fix-rmmod-read-write-races-in-proc-entries.patch doesn't want dynamically
allocated ->proc_fops, because it will set it to NULL at module unload time.

Regardless of module status, switch to statically allocated ->proc_fops which
leads to simpler code without wrappers.

AFAICS, also fix the following bug: "sn_force_interrupt" proc entry set
->write for itself, but was created with 0444 permissions. Change to 0644.

Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 62 insertions, 43 deletions

diff --git a/arch/ia64/sn/kernel/sn2/sn_proc_fs.c b/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
index 43ddc2eccb96..62b3e9a496ac 100644
--- a/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
+++ b/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
@@ -89,61 +89,80 @@ static int coherence_id_open(struct inode *inode, struct file *file)
         return single_open(file, coherence_id_show, NULL);
 }
 
-static struct proc_dir_entry
-*sn_procfs_create_entry(const char *name, struct proc_dir_entry *parent,
-                        int (*openfunc)(struct inode *, struct file *),
-        int (*releasefunc)(struct inode *, struct file *),
-        ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *))
-{
-        struct proc_dir_entry *e = create_proc_entry(name, 0444, parent);
-
-        if (e) {
-                struct file_operations *f;
-
-                f = kzalloc(sizeof(*f), GFP_KERNEL);
-                if (f) {
-                        f->open = openfunc;
-                        f->read = seq_read;
-                        f->llseek = seq_lseek;
-                        f->release = releasefunc;
-                        f->write = write;
-                        e->proc_fops = f;
-                }
-        }
-
-        return e;
-}
-
 /* /proc/sgi_sn/sn_topology uses seq_file, see sn_hwperf.c */
 extern int sn_topology_open(struct inode *, struct file *);
 extern int sn_topology_release(struct inode *, struct file *);
 
+static const struct file_operations proc_partition_id_fops = {
+        .open           = partition_id_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static const struct file_operations proc_system_sn_fops = {
+        .open           = system_serial_number_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static const struct file_operations proc_license_id_fops = {
+        .open           = licenseID_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static const struct file_operations proc_sn_force_intr_fops = {
+        .open           = sn_force_interrupt_open,
+        .read           = seq_read,
+        .write          = sn_force_interrupt_write_proc,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static const struct file_operations proc_coherence_id_fops = {
+        .open           = coherence_id_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+static const struct file_operations proc_sn_topo_fops = {
+        .open           = sn_topology_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = sn_topology_release,
+};
+
 void register_sn_procfs(void)
 {
         static struct proc_dir_entry *sgi_proc_dir = NULL;
+        struct proc_dir_entry *pde;
 
         BUG_ON(sgi_proc_dir != NULL);
         if (!(sgi_proc_dir = proc_mkdir("sgi_sn", NULL)))
                 return;
 
-        sn_procfs_create_entry("partition_id", sgi_proc_dir,
-                partition_id_open, single_release, NULL);
-
-        sn_procfs_create_entry("system_serial_number", sgi_proc_dir,
-                system_serial_number_open, single_release, NULL);
-
-        sn_procfs_create_entry("licenseID", sgi_proc_dir, 
-                licenseID_open, single_release, NULL);
-
-        sn_procfs_create_entry("sn_force_interrupt", sgi_proc_dir,
-                sn_force_interrupt_open, single_release,
-                sn_force_interrupt_write_proc);
-
-        sn_procfs_create_entry("coherence_id", sgi_proc_dir, 
-                coherence_id_open, single_release, NULL);
-        
-        sn_procfs_create_entry("sn_topology", sgi_proc_dir,
-                sn_topology_open, sn_topology_release, NULL);
+        pde = create_proc_entry("partition_id", 0444, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_partition_id_fops;
+        pde = create_proc_entry("system_serial_number", 0444, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_system_sn_fops;
+        pde = create_proc_entry("licenseID", 0444, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_license_id_fops;
+        pde = create_proc_entry("sn_force_interrupt", 0644, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_sn_force_intr_fops;
+        pde = create_proc_entry("coherence_id", 0444, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_coherence_id_fops;
+        pde = create_proc_entry("sn_topology", 0444, sgi_proc_dir);
+        if (pde)
+                pde->proc_fops = &proc_sn_topo_fops;
 }
 
 #endif /* CONFIG_PROC_FS */