dgrp procfs fixes, part 4: get rid of sysctl-like machinery
authorAl Viro <viro@zeniv.linux.org.uk>
Sat, 30 Mar 2013 04:36:23 +0000 (00:36 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Tue, 9 Apr 2013 18:13:08 +0000 (14:13 -0400)
racy and very overblown...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
drivers/staging/dgrp/dgrp_common.h
drivers/staging/dgrp/dgrp_specproc.c

index fde116236e9846307542887f413975b356912334..99e231c3c60284021a5ce5a16542ae0ed90087d3 100644 (file)
@@ -76,61 +76,6 @@ extern void dgrp_create_tty_sysfs(struct un_struct *un, struct device *c);
 extern void dgrp_remove_tty_sysfs(struct device *c);
 
 /* from dgrp_specproc.c */
-/*
- *  The list of DGRP entries with r/w capabilities.  These
- *  magic numbers are used for identification purposes.
- */
-enum {
-       DGRP_CONFIG = 1,        /* Configure portservers */
-       DGRP_NETDIR = 2,        /* Directory for "net" devices */
-       DGRP_MONDIR = 3,        /* Directory for "mon" devices */
-       DGRP_PORTSDIR = 4,      /* Directory for "ports" devices */
-       DGRP_INFO = 5,          /* Get info. about the running module */
-       DGRP_NODEINFO = 6,      /* Get info. about the configured nodes */
-       DGRP_DPADIR = 7,        /* Directory for the "dpa" devices */
-};
-
-/*
- *  Directions for proc handlers
- */
-enum {
-       INBOUND = 1,            /* Data being written to kernel */
-       OUTBOUND = 2,           /* Data being read from the kernel */
-};
-
-/**
- * dgrp_proc_entry: structure for dgrp proc dirs
- * @id: ID number associated with this particular entry.  Should be
- *    unique across all of DGRP.
- * @name: text name associated with the /proc entry
- * @mode: file access permisssions for the /proc entry
- * @child: pointer to table describing a subdirectory for this entry
- * @de: pointer to directory entry for this object once registered.  Used
- *    to grab the handle of the object for unregistration
- * @excl_sem: semaphore to provide exclusive to struct
- * @excl_cnt: counter of current accesses
- *
- *  Each entry in a DGRP proc directory is described with a
- *  dgrp_proc_entry structure.  A collection of these
- *  entries (in an array) represents the members associated
- *  with a particular /proc directory, and is referred to
- *  as a table.  All tables are terminated by an entry with
- *  zeros for every member.
- */
-struct dgrp_proc_entry {
-       int                  id;          /* Integer identifier */
-       const char        *name;          /* ASCII identifier */
-       umode_t            mode;          /* File access permissions */
-       struct dgrp_proc_entry *child;    /* Child pointer */
-
-       /* file ops to use, pass NULL to use default */
-       struct file_operations *proc_file_ops;
-
-       struct proc_dir_entry *de;        /* proc entry pointer */
-       struct semaphore   excl_sem;      /* Protects exclusive access var */
-       int                excl_cnt;      /* Counts number of curr accesses */
-};
-
 extern void dgrp_unregister_proc(void);
 extern void dgrp_register_proc(void);
 
index 1ccf10ce85cdc022212183e8e007dbd8d0be51d7..caf4faccf42d4f5310e02326af6623f091071cad 100644 (file)
@@ -44,7 +44,6 @@
 
 #include "dgrp_common.h"
 
-static struct dgrp_proc_entry dgrp_table[];
 static struct proc_dir_entry *dgrp_proc_dir_entry;
 
 static int dgrp_add_id(long id);
@@ -63,16 +62,6 @@ static struct inode_operations proc_inode_ops = {
 };
 
 
-static void register_proc_table(struct dgrp_proc_entry *,
-                               struct proc_dir_entry *);
-static void unregister_proc_table(struct dgrp_proc_entry *,
-                                 struct proc_dir_entry *);
-
-static struct dgrp_proc_entry dgrp_net_table[];
-static struct dgrp_proc_entry dgrp_mon_table[];
-static struct dgrp_proc_entry dgrp_ports_table[];
-static struct dgrp_proc_entry dgrp_dpa_table[];
-
 static ssize_t dgrp_config_proc_write(struct file *file,
                                      const char __user *buffer,
                                      size_t count, loff_t *pos);
@@ -106,72 +95,11 @@ static struct file_operations nodeinfo_proc_file_ops = {
        .release = seq_release,
 };
 
-static struct dgrp_proc_entry dgrp_table[] = {
-       {
-               .id = DGRP_CONFIG,
-               .name = "config",
-               .mode = 0644,
-               .proc_file_ops = &config_proc_file_ops,
-       },
-       {
-               .id = DGRP_INFO,
-               .name = "info",
-               .mode = 0644,
-               .proc_file_ops = &info_proc_file_ops,
-       },
-       {
-               .id = DGRP_NODEINFO,
-               .name = "nodeinfo",
-               .mode = 0644,
-               .proc_file_ops = &nodeinfo_proc_file_ops,
-       },
-       {
-               .id = DGRP_NETDIR,
-               .name = "net",
-               .mode = 0500,
-               .child = dgrp_net_table
-       },
-       {
-               .id = DGRP_MONDIR,
-               .name = "mon",
-               .mode = 0500,
-               .child = dgrp_mon_table
-       },
-       {
-               .id = DGRP_PORTSDIR,
-               .name = "ports",
-               .mode = 0500,
-               .child = dgrp_ports_table
-       },
-       {
-               .id = DGRP_DPADIR,
-               .name = "dpa",
-               .mode = 0500,
-               .child = dgrp_dpa_table
-       }
-};
-
 static struct proc_dir_entry *net_entry_pointer;
 static struct proc_dir_entry *mon_entry_pointer;
 static struct proc_dir_entry *dpa_entry_pointer;
 static struct proc_dir_entry *ports_entry_pointer;
 
-static struct dgrp_proc_entry dgrp_net_table[] = {
-       {0}
-};
-
-static struct dgrp_proc_entry dgrp_mon_table[] = {
-       {0}
-};
-
-static struct dgrp_proc_entry dgrp_ports_table[] = {
-       {0}
-};
-
-static struct dgrp_proc_entry dgrp_dpa_table[] = {
-       {0}
-};
-
 void dgrp_unregister_proc(void)
 {
        net_entry_pointer = NULL;
@@ -180,163 +108,62 @@ void dgrp_unregister_proc(void)
        ports_entry_pointer = NULL;
 
        if (dgrp_proc_dir_entry) {
-               unregister_proc_table(dgrp_table, dgrp_proc_dir_entry);
-               remove_proc_entry(dgrp_proc_dir_entry->name,
-                                 dgrp_proc_dir_entry->parent);
+               struct nd_struct *nd;
+               list_for_each_entry(nd, &nd_struct_list, list) {
+                       if (nd->nd_net_de) {
+                               unregister_dgrp_device(nd->nd_net_de);
+                               dgrp_remove_node_class_sysfs_files(nd);
+                       }
+
+                       if (nd->nd_mon_de)
+                               unregister_dgrp_device(nd->nd_mon_de);
+
+                       if (nd->nd_dpa_de)
+                               unregister_dgrp_device(nd->nd_dpa_de);
+
+                       if (nd->nd_ports_de)
+                               unregister_dgrp_device(nd->nd_ports_de);
+               }
+               remove_proc_entry("dgrp/config", NULL);
+               remove_proc_entry("dgrp/info", NULL);
+               remove_proc_entry("dgrp/nodeinfo", NULL);
+               remove_proc_entry("dgrp/net", NULL);
+               remove_proc_entry("dgrp/mon", NULL);
+               remove_proc_entry("dgrp/dpa", NULL);
+               remove_proc_entry("dgrp/ports", NULL);
+               remove_proc_entry("dgrp", NULL);
                dgrp_proc_dir_entry = NULL;
        }
-
 }
 
 void dgrp_register_proc(void)
 {
+       struct proc_dir_entry *de;
        /*
         *      Register /proc/dgrp
         */
        dgrp_proc_dir_entry = proc_mkdir("dgrp", NULL);
-       register_proc_table(dgrp_table, dgrp_proc_dir_entry);
-}
-
-/*
- * /proc/sys support
- */
-static int dgrp_proc_match(int len, const char *name, struct proc_dir_entry *de)
-{
-       if (!de || !de->low_ino)
-               return 0;
-       if (de->namelen != len)
-               return 0;
-       return !memcmp(name, de->name, len);
-}
-
-
-/*
- *  Scan the entries in table and add them all to /proc at the position
- *  referred to by "root"
- */
-static void register_proc_table(struct dgrp_proc_entry *table,
-                               struct proc_dir_entry *root)
-{
-       struct proc_dir_entry *de;
-       int len;
-       umode_t mode;
-
-       if (table == NULL)
+       if (!dgrp_proc_dir_entry)
                return;
-       if (root == NULL)
-               return;
-
-       for (; table->id; table++) {
-               /* Can't do anything without a proc name. */
-               if (!table->name)
-                       continue;
-
-               /* Maybe we can't do anything with it... */
-               if (!table->proc_file_ops &&
-                   !table->child) {
-                       pr_warn("dgrp: Can't register %s\n",
-                               table->name);
-                       continue;
-               }
-
-               len = strlen(table->name);
-               mode = table->mode;
-
-               de = NULL;
-               if (!table->child)
-                       mode |= S_IFREG;
-               else {
-                       mode |= S_IFDIR;
-                       for (de = root->subdir; de; de = de->next) {
-                               if (dgrp_proc_match(len, table->name, de))
-                                       break;
-                       }
-                       /* If the subdir exists already, de is non-NULL */
-               }
-
-               if (!de) {
-                       de = create_proc_entry(table->name, mode, root);
-                       if (!de)
-                               continue;
-                       de->data = (void *) table;
-                       if (!table->child) {
-                               de->proc_iops = &proc_inode_ops;
-                               de->proc_fops = table->proc_file_ops;
-                       }
-               }
-               table->de = de;
-               if (de->mode & S_IFDIR)
-                       register_proc_table(table->child, de);
-
-               if (table->id == DGRP_NETDIR)
-                       net_entry_pointer = de;
-
-               if (table->id == DGRP_MONDIR)
-                       mon_entry_pointer = de;
-
-               if (table->id == DGRP_DPADIR)
-                       dpa_entry_pointer = de;
-
-               if (table->id == DGRP_PORTSDIR)
-                       ports_entry_pointer = de;
+       de = create_proc_entry("dgrp/config", 0644, NULL);
+       if (de) {
+               de->proc_fops = &config_proc_file_ops;
+               de->proc_iops = &proc_inode_ops;
        }
-}
-
-/*
- * Unregister a /proc sysctl table and any subdirectories.
- */
-static void unregister_proc_table(struct dgrp_proc_entry *table,
-                                 struct proc_dir_entry *root)
-{
-       struct proc_dir_entry *de;
-       struct nd_struct *tmp;
-
-       if (table == NULL)
-               return;
-
-       list_for_each_entry(tmp, &nd_struct_list, list) {
-               if ((table == dgrp_net_table) && (tmp->nd_net_de)) {
-                       unregister_dgrp_device(tmp->nd_net_de);
-                       dgrp_remove_node_class_sysfs_files(tmp);
-               }
-
-               if ((table == dgrp_mon_table) && (tmp->nd_mon_de))
-                       unregister_dgrp_device(tmp->nd_mon_de);
-
-               if ((table == dgrp_dpa_table) && (tmp->nd_dpa_de))
-                       unregister_dgrp_device(tmp->nd_dpa_de);
-
-               if ((table == dgrp_ports_table) && (tmp->nd_ports_de))
-                       unregister_dgrp_device(tmp->nd_ports_de);
+       de = create_proc_entry("dgrp/info", 0644, NULL);
+       if (de) {
+               de->proc_fops = &info_proc_file_ops;
+               de->proc_iops = &proc_inode_ops;
        }
-
-       for (; table->id; table++) {
-               de = table->de;
-
-               if (!de)
-                       continue;
-               if (de->mode & S_IFDIR) {
-                       if (!table->child) {
-                               pr_alert("dgrp: malformed sysctl tree on free\n");
-                               continue;
-                       }
-                       unregister_proc_table(table->child, de);
-
-       /* Don't unregister directories which still have entries */
-                       if (de->subdir)
-                               continue;
-               }
-
-               /* Don't unregister proc entries that are still being used.. */
-               if ((atomic_read(&de->count)) != 1) {
-                       pr_alert("proc entry %s in use, not removing\n",
-                               de->name);
-                       continue;
-               }
-
-               remove_proc_entry(de->name, de->parent);
-               table->de = NULL;
+       de = create_proc_entry("dgrp/nodeinfo", 0644, NULL);
+       if (de) {
+               de->proc_fops = &nodeinfo_proc_file_ops;
+               de->proc_iops = &proc_inode_ops;
        }
+       net_entry_pointer = proc_mkdir_mode("dgrp/net", 0500, NULL);
+       mon_entry_pointer = proc_mkdir_mode("dgrp/mon", 0500, NULL);
+       dpa_entry_pointer = proc_mkdir_mode("dgrp/dpa", 0500, NULL);
+       ports_entry_pointer = proc_mkdir_mode("dgrp/ports", 0500, NULL);
 }
 
 static void *dgrp_config_proc_start(struct seq_file *m, loff_t *pos)