From: Nathan Lynch <nathanl@austin.ibm.com>
On some larger ppc64 configurations /proc/device-tree is exhausting procfs'
dynamic (non-pid) inode range (16K). This patch makes the dynamic inode
range 0xf0000000-0xffffffff and changes the inode number allocator to use
the idr.c allocator for the first-fit allocations.
---
25-akpm/fs/proc/generic.c | 77 +++++++++++++++++++++++++++-------------
25-akpm/fs/proc/inode-alloc.txt | 5 +-
25-akpm/fs/proc/inode.c | 11 ++---
25-akpm/include/linux/proc_fs.h | 7 +--
4 files changed, 62 insertions(+), 38 deletions(-)
diff -puN fs/proc/generic.c~increase-number-of-dynamic-inodes-in-procfs-265 fs/proc/generic.c
--- 25/fs/proc/generic.c~increase-number-of-dynamic-inodes-in-procfs-265 2004-04-14 19:45:17.791055328 -0700
+++ 25-akpm/fs/proc/generic.c 2004-04-14 20:03:47.052421968 -0700
@@ -15,6 +15,8 @@
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <linux/idr.h>
#include <asm/uaccess.h>
#include <asm/bitops.h>
@@ -275,24 +277,51 @@ static int xlate_proc_name(const char *n
return 0;
}
-static unsigned long proc_alloc_map[(PROC_NDYNAMIC + BITS_PER_LONG - 1) / BITS_PER_LONG];
+static struct idr proc_inum_idr;
+static spinlock_t proc_inum_lock = SPIN_LOCK_UNLOCKED; /* protects the above */
-spinlock_t proc_alloc_map_lock = SPIN_LOCK_UNLOCKED;
+#define PROC_DYNAMIC_FIRST 0xF0000000UL
-static int make_inode_number(void)
+void __init init_proc_inum_idr(void)
{
- int i;
- spin_lock(&proc_alloc_map_lock);
- i = find_first_zero_bit(proc_alloc_map, PROC_NDYNAMIC);
- if (i < 0 || i >= PROC_NDYNAMIC) {
- i = -1;
- goto out;
- }
- set_bit(i, proc_alloc_map);
- i += PROC_DYNAMIC_FIRST;
-out:
- spin_unlock(&proc_alloc_map_lock);
- return i;
+ idr_init(&proc_inum_idr);
+}
+
+/*
+ * Return an inode number between PROC_DYNAMIC_FIRST and
+ * 0xffffffff, or zero on failure.
+ */
+static unsigned int get_inode_number(void)
+{
+ unsigned int i, inum = 0;
+
+retry:
+ if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0)
+ return 0;
+
+ spin_lock(&proc_inum_lock);
+ i = idr_get_new(&proc_inum_idr, NULL);
+ spin_unlock(&proc_inum_lock);
+
+ if (i == -1)
+ goto retry;
+
+ inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST;
+
+ /* inum will never be more than 0xf0ffffff, so no check
+ * for overflow.
+ */
+
+ return inum;
+}
+
+static void release_inode_number(unsigned int inum)
+{
+ int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK;
+
+ spin_lock(&proc_inum_lock);
+ idr_remove(&proc_inum_idr, id);
+ spin_unlock(&proc_inum_lock);
}
static int
@@ -346,7 +375,7 @@ struct dentry *proc_lookup(struct inode
if (de->namelen != dentry->d_name.len)
continue;
if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
- int ino = de->low_ino;
+ unsigned int ino = de->low_ino;
error = -EINVAL;
inode = proc_get_inode(dir->i_sb, ino, de);
break;
@@ -452,10 +481,10 @@ static struct inode_operations proc_dir_
static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
{
- int i;
+ unsigned int i;
- i = make_inode_number();
- if (i < 0)
+ i = get_inode_number();
+ if (i == 0)
return -EAGAIN;
dp->low_ino = i;
dp->next = dir->subdir;
@@ -621,11 +650,13 @@ struct proc_dir_entry *create_proc_entry
void free_proc_entry(struct proc_dir_entry *de)
{
- int ino = de->low_ino;
+ unsigned int ino = de->low_ino;
- if (ino < PROC_DYNAMIC_FIRST ||
- ino >= PROC_DYNAMIC_FIRST+PROC_NDYNAMIC)
+ if (ino < PROC_DYNAMIC_FIRST)
return;
+
+ release_inode_number(ino);
+
if (S_ISLNK(de->mode) && de->data)
kfree(de->data);
kfree(de);
@@ -653,8 +684,6 @@ void remove_proc_entry(const char *name,
de->next = NULL;
if (S_ISDIR(de->mode))
parent->nlink--;
- clear_bit(de->low_ino - PROC_DYNAMIC_FIRST,
- proc_alloc_map);
proc_kill_inodes(de);
de->nlink = 0;
WARN_ON(de->subdir);
diff -puN fs/proc/inode-alloc.txt~increase-number-of-dynamic-inodes-in-procfs-265 fs/proc/inode-alloc.txt
--- 25/fs/proc/inode-alloc.txt~increase-number-of-dynamic-inodes-in-procfs-265 2004-04-14 19:45:17.792055176 -0700
+++ 25-akpm/fs/proc/inode-alloc.txt 2004-04-14 19:45:17.799054112 -0700
@@ -4,9 +4,10 @@ Current inode allocations in the proc-fs
00000001-00000fff static entries (goners)
001 root-ino
- 00001000-00001fff dynamic entries
+ 00001000-00001fff unused
0001xxxx-7fffxxxx pid-dir entries for pid 1-7fff
- 80000000-ffffffff unused
+ 80000000-efffffff unused
+ f0000000-ffffffff dynamic entries
Goal:
a) once we'll split the thing into several virtual filesystems we
diff -puN fs/proc/inode.c~increase-number-of-dynamic-inodes-in-procfs-265 fs/proc/inode.c
--- 25/fs/proc/inode.c~increase-number-of-dynamic-inodes-in-procfs-265 2004-04-14 19:45:17.793055024 -0700
+++ 25-akpm/fs/proc/inode.c 2004-04-14 19:46:32.874640888 -0700
@@ -181,8 +181,8 @@ static int parse_options(char *options,u
return 1;
}
-struct inode * proc_get_inode(struct super_block * sb, int ino,
- struct proc_dir_entry * de)
+struct inode *proc_get_inode(struct super_block *sb, unsigned int ino,
+ struct proc_dir_entry *de)
{
struct inode * inode;
@@ -190,11 +190,8 @@ struct inode * proc_get_inode(struct sup
* Increment the use count so the dir entry can't disappear.
*/
de_get(de);
-#if 1
-/* shouldn't ever happen */
-if (de && de->deleted)
-printk("proc_iget: using deleted entry %s, count=%d\n", de->name, atomic_read(&de->count));
-#endif
+
+ WARN_ON(de && de->deleted);
inode = iget(sb, ino);
if (!inode)
diff -puN include/linux/proc_fs.h~increase-number-of-dynamic-inodes-in-procfs-265 include/linux/proc_fs.h
--- 25/include/linux/proc_fs.h~increase-number-of-dynamic-inodes-in-procfs-265 2004-04-14 19:45:17.795054720 -0700
+++ 25-akpm/include/linux/proc_fs.h 2004-04-14 19:45:17.800053960 -0700
@@ -26,9 +26,6 @@ enum {
/* Finally, the dynamically allocatable proc entries are reserved: */
-#define PROC_DYNAMIC_FIRST 4096
-#define PROC_NDYNAMIC 16384
-
#define PROC_SUPER_MAGIC 0x9fa0
/*
@@ -53,7 +50,7 @@ typedef int (write_proc_t)(struct file *
typedef int (get_info_t)(char *, char **, off_t, int);
struct proc_dir_entry {
- unsigned short low_ino;
+ unsigned int low_ino;
unsigned short namelen;
const char *name;
mode_t mode;
@@ -102,7 +99,7 @@ extern void remove_proc_entry(const char
extern struct vfsmount *proc_mnt;
extern int proc_fill_super(struct super_block *,void *,int);
-extern struct inode * proc_get_inode(struct super_block *, int, struct proc_dir_entry *);
+extern struct inode *proc_get_inode(struct super_block *, unsigned int, struct proc_dir_entry *);
extern int proc_match(int, const char *,struct proc_dir_entry *);
_