On Tue, 2006-11-14 at 20:26 +0000, Al Viro wrote:
> NAK. All calls of new_inode() are triggered from within fs code;
> there's no reason to introduce flags (which should be the last
> resort) when you bloody well can have a separate helpers for that
> case and have them called. Explicitly.
Ok, that sounds reasonable. Here's a respun patch. This adds 2 new
functions, an idr_register and idr_unregister. Filesystems can call
idr_register at inode creation time, and then at deletion time, we'll
automatically unregister them. Again, this contains a conversion of
pipefs to this scheme as an example. If this looks good, I'll start on
the legwork to clean up the other filesystems that call new_inode.
This patch also adds a new s_generation counter to the superblock.
Because i_ino's can be reused so quickly, we don't want NFS getting
confused when it happens. When iunique_register is called, we'll assign
the s_generation value to the i_generation, and then increment it to
help ensure that we get different filehandles.
I've left the original iunique function in place here, and new_inode
still has the static counter, but that stuff can all be ripped out once
I convert the filesystems to the new scheme.
Again, comments appreciated...
-- Jeff
diff --git a/fs/inode.c b/fs/inode.c
index 26cdb11..b63b473 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -288,6 +288,8 @@ static void dispose_list(struct list_hea
list_del_init(&inode->i_sb_list);
spin_unlock(&inode_lock);
+ iunique_unregister(inode);
+
wake_up_inode(inode);
destroy_inode(inode);
nr_disposed++;
@@ -706,6 +708,34 @@ retry:
EXPORT_SYMBOL(iunique);
+int iunique_register(struct inode *inode, int max_reserved)
+{
+ int rv;
+
+ rv = idr_pre_get(&inode->i_sb->s_inode_ids, GFP_KERNEL);
+ if (! rv)
+ return -ENOMEM;
+
+ lock_super(inode->i_sb);
+ rv = idr_get_new_above(&inode->i_sb->s_inode_ids, inode,
+ max_reserved+1, (int *) &inode->i_ino);
+ inode->i_generation = inode->i_sb->s_generation++;
+ unlock_super(inode->i_sb);
+ return rv;
+}
+
+EXPORT_SYMBOL(iunique_register);
+
+void iunique_unregister(struct inode *inode)
+{
+ lock_super(inode->i_sb);
+ if (idr_find(&inode->i_sb->s_inode_ids, (int) inode->i_ino))
+ idr_remove(&inode->i_sb->s_inode_ids, (int) inode->i_ino);
+ unlock_super(inode->i_sb);
+}
+
+EXPORT_SYMBOL(iunique_unregister);
+
struct inode *igrab(struct inode *inode)
{
spin_lock(&inode_lock);
@@ -1025,6 +1055,7 @@ void generic_delete_inode(struct inode *
spin_lock(&inode_lock);
hlist_del_init(&inode->i_hash);
spin_unlock(&inode_lock);
+ iunique_unregister(inode);
wake_up_inode(inode);
BUG_ON(inode->i_state != I_CLEAR);
destroy_inode(inode);
@@ -1057,6 +1088,7 @@ static void generic_forget_inode(struct
inode->i_state |= I_FREEING;
inodes_stat.nr_inodes--;
spin_unlock(&inode_lock);
+ iunique_unregister(inode);
if (inode->i_data.nrpages)
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
diff --git a/fs/pipe.c b/fs/pipe.c
index b1626f2..d74ae65 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -845,6 +845,9 @@ static struct inode * get_pipe_inode(voi
if (!inode)
goto fail_inode;
+ if (iunique_register(inode, 0))
+ goto fail_iput;
+
pipe = alloc_pipe_info(inode);
if (!pipe)
goto fail_iput;
diff --git a/fs/super.c b/fs/super.c
index 47e554c..23b662b 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -93,6 +93,7 @@ static struct super_block *alloc_super(s
s->s_qcop = sb_quotactl_ops;
s->s_op = &default_op;
s->s_time_gran = 1000000000;
+ idr_init(&s->s_inode_ids);
}
out:
return s;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2fe6e3f..c05bf23 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -278,6 +278,7 @@ #include <linux/prio_tree.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/mutex.h>
+#include <linux/idr.h>
#include <asm/atomic.h>
#include <asm/semaphore.h>
@@ -961,6 +962,11 @@ #endif
/* Granularity of c/m/atime in ns.
Cannot be worse than a second */
u32 s_time_gran;
+
+ /* for fs's with dynamic i_ino values, track them with idr, and increment
+ the generation every time we register a new inode */
+ __u32 s_generation;
+ struct idr s_inode_ids;
};
extern struct timespec current_fs_time(struct super_block *sb);
@@ -1681,6 +1687,8 @@ extern void inode_init_once(struct inode
extern void iput(struct inode *);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
+extern int iunique_register(struct inode *, int);
+extern void iunique_unregister(struct inode *);
extern int inode_needs_sync(struct inode *inode);
extern void generic_delete_inode(struct inode *inode);
extern void generic_drop_inode(struct inode *inode);
diff --git a/lib/idr.c b/lib/idr.c
-
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