From: Tim Hockin <thockin@sun.com>
Remove the max_anon via dynamically allocation. We also change the
idr_pre_get() interface to take a gfp mask, which should have always been
there.
---
fs/super.c | 28 ++++++++++++++++++++--------
include/linux/fs.h | 1 +
include/linux/idr.h | 2 +-
init/main.c | 1 +
kernel/posix-timers.c | 2 +-
lib/idr.c | 12 ++++++------
6 files changed, 30 insertions(+), 16 deletions(-)
diff -puN fs/super.c~increase-max_anon fs/super.c
--- 25/fs/super.c~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/fs/super.c 2004-02-11 19:20:16.000000000 -0800
@@ -23,6 +23,7 @@
#include <linux/config.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/acct.h>
#include <linux/blkdev.h>
@@ -33,6 +34,7 @@
#include <linux/security.h>
#include <linux/vfs.h>
#include <linux/writeback.h> /* for the emergency remount stuff */
+#include <linux/idr.h>
#include <asm/uaccess.h>
@@ -536,22 +538,26 @@ void emergency_remount(void)
* filesystems which don't use real block-devices. -- jrs
*/
-enum {Max_anon = 256};
-static unsigned long unnamed_dev_in_use[Max_anon/(8*sizeof(unsigned long))];
+static struct idr unnamed_dev_idr;
static spinlock_t unnamed_dev_lock = SPIN_LOCK_UNLOCKED;/* protects the above */
int set_anon_super(struct super_block *s, void *data)
{
int dev;
+
spin_lock(&unnamed_dev_lock);
- dev = find_first_zero_bit(unnamed_dev_in_use, Max_anon);
- if (dev == Max_anon) {
+ if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0) {
spin_unlock(&unnamed_dev_lock);
- return -EMFILE;
+ return -ENOMEM;
}
- set_bit(dev, unnamed_dev_in_use);
+ dev = idr_get_new(&unnamed_dev_idr, NULL);
spin_unlock(&unnamed_dev_lock);
- s->s_dev = MKDEV(0, dev);
+
+ if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
+ idr_remove(&unnamed_dev_idr, dev);
+ return -EMFILE;
+ }
+ s->s_dev = MKDEV(0, dev & MINORMASK);
return 0;
}
@@ -560,14 +566,20 @@ EXPORT_SYMBOL(set_anon_super);
void kill_anon_super(struct super_block *sb)
{
int slot = MINOR(sb->s_dev);
+
generic_shutdown_super(sb);
spin_lock(&unnamed_dev_lock);
- clear_bit(slot, unnamed_dev_in_use);
+ idr_remove(&unnamed_dev_idr, slot);
spin_unlock(&unnamed_dev_lock);
}
EXPORT_SYMBOL(kill_anon_super);
+void __init unnamed_dev_init(void)
+{
+ idr_init(&unnamed_dev_idr);
+}
+
void kill_litter_super(struct super_block *sb)
{
if (sb->s_root)
diff -puN include/linux/fs.h~increase-max_anon include/linux/fs.h
--- 25/include/linux/fs.h~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/include/linux/fs.h 2004-02-11 19:20:16.000000000 -0800
@@ -1051,6 +1051,7 @@ struct super_block *sget(struct file_sys
void *data);
struct super_block *get_sb_pseudo(struct file_system_type *, char *,
struct super_operations *ops, unsigned long);
+void unnamed_dev_init(void);
/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
#define fops_get(fops) \
diff -puN include/linux/idr.h~increase-max_anon include/linux/idr.h
--- 25/include/linux/idr.h~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/include/linux/idr.h 2004-02-11 19:20:16.000000000 -0800
@@ -58,7 +58,7 @@ struct idr {
*/
void *idr_find(struct idr *idp, int id);
-int idr_pre_get(struct idr *idp);
+int idr_pre_get(struct idr *idp, unsigned gfp_mask);
int idr_get_new(struct idr *idp, void *ptr);
void idr_remove(struct idr *idp, int id);
void idr_init(struct idr *idp);
diff -puN init/main.c~increase-max_anon init/main.c
--- 25/init/main.c~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/init/main.c 2004-02-11 19:20:16.000000000 -0800
@@ -473,6 +473,7 @@ asmlinkage void __init start_kernel(void
fork_init(num_physpages);
proc_caches_init();
buffer_init();
+ unnamed_dev_init();
security_scaffolding_startup();
vfs_caches_init(num_physpages);
radix_tree_init();
diff -puN kernel/posix-timers.c~increase-max_anon kernel/posix-timers.c
--- 25/kernel/posix-timers.c~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/kernel/posix-timers.c 2004-02-11 19:20:16.000000000 -0800
@@ -426,7 +426,7 @@ sys_timer_create(clockid_t which_clock,
spin_lock_init(&new_timer->it_lock);
do {
- if (unlikely(!idr_pre_get(&posix_timers_id))) {
+ if (unlikely(!idr_pre_get(&posix_timers_id, GFP_KERNEL))) {
error = -EAGAIN;
new_timer->it_id = (timer_t)-1;
goto out;
diff -puN lib/idr.c~increase-max_anon lib/idr.c
--- 25/lib/idr.c~increase-max_anon 2004-02-11 19:20:16.000000000 -0800
+++ 25-akpm/lib/idr.c 2004-02-11 19:20:16.000000000 -0800
@@ -62,13 +62,13 @@
* to the rest of the functions. The structure is defined in the
* header.
- * int idr_pre_get(struct idr *idp)
+ * int idr_pre_get(struct idr *idp, unsigned gfp_mask)
* This function should be called prior to locking and calling the
* following function. It pre allocates enough memory to satisfy the
- * worst possible allocation. It can sleep, so must not be called
- * with any spinlocks held. If the system is REALLY out of memory
- * this function returns 0, other wise 1.
+ * worst possible allocation. Unless gfp_mask is GFP_ATOMIC, it can
+ * sleep, so must not be called with any spinlocks held. If the system is
+ * REALLY out of memory this function returns 0, other wise 1.
* int idr_get_new(struct idr *idp, void *ptr);
@@ -135,11 +135,11 @@ static inline void free_layer(struct idr
spin_unlock(&idp->lock);
}
-int idr_pre_get(struct idr *idp)
+int idr_pre_get(struct idr *idp, unsigned gfp_mask)
{
while (idp->id_free_cnt < idp->layers + 1) {
struct idr_layer *new;
- new = kmem_cache_alloc(idr_layer_cache, GFP_KERNEL);
+ new = kmem_cache_alloc(idr_layer_cache, gfp_mask);
if(new == NULL)
return (0);
free_layer(idp, new);
_