- add a new per superblock s_nextino counter and change iunique to use it
instead of its global inode counter
- make the size of the counter conditional on CONFIG_COMPAT. This is to try
prevent userspace EOVERFLOWs when 32-bit programs not compiled with large
offsets are run on 64-bit kernels
- add new_inode_autonum which guarantees that i_ino is assigned a unique val
on the filesystem.
- Change new_inode to assign i_ino to 0 to catch filesystems that use it and
don't reset it to a unique value.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Acked-by: Joern Engel <joern@xxxxxxxxxxxxxx>
diff --git a/fs/inode.c b/fs/inode.c
index 26cdb11..cbe466f 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -517,14 +517,14 @@ repeat:
}
/**
- * new_inode - obtain an inode
+ * __new_inode - obtain an inode
* @sb: superblock
+ * @autonum: if true, make sure that i_ino is unique
*
* Allocates a new inode for given superblock.
*/
-struct inode *new_inode(struct super_block *sb)
+static struct inode *__new_inode(struct super_block *sb)
{
- static unsigned long last_ino;
struct inode * inode;
spin_lock_prefetch(&inode_lock);
@@ -535,13 +535,46 @@ struct inode *new_inode(struct super_blo
inodes_stat.nr_inodes++;
list_add(&inode->i_list, &inode_in_use);
list_add(&inode->i_sb_list, &sb->s_inodes);
- inode->i_ino = ++last_ino;
inode->i_state = 0;
spin_unlock(&inode_lock);
}
return inode;
}
+/**
+ * new_inode_autonum - obtain an inode with a unique i_ino value
+ * @sb: superblock
+ *
+ * Allocates a new inode for given superblock. Ensures that i_ino is
+ * unique on the filesystem.
+ */
+struct inode *new_inode_autonum(struct super_block *sb)
+{
+ struct inode *inode;
+
+ inode = __new_inode(sb);
+ inode->i_ino = iunique(sb, 0);
+ return inode;
+}
+
+EXPORT_SYMBOL(new_inode_autonum);
+
+/**
+ * new_inode - obtain an inode -- i_ino not guaranteed unique
+ * @sb: superblock
+ *
+ * Allocates a new inode for given superblock. i_ino is not guaranteed to
+ * be unique. Should only be used when i_ino is going to be clobbered.
+ */
+struct inode *new_inode(struct super_block *sb)
+{
+ struct inode *inode;
+
+ inode = __new_inode(sb);
+ inode->i_ino = 0; /* 0 to try to catch callers that don't reset it */
+ return inode;
+}
+
EXPORT_SYMBOL(new_inode);
void unlock_new_inode(struct inode *inode)
@@ -683,22 +716,21 @@ static unsigned long hash(struct super_b
*/
ino_t iunique(struct super_block *sb, ino_t max_reserved)
{
- static ino_t counter;
struct inode *inode;
struct hlist_head * head;
ino_t res;
spin_lock(&inode_lock);
retry:
- if (counter > max_reserved) {
- head = inode_hashtable + hash(sb,counter);
- res = counter++;
+ if (sb->s_nextino > max_reserved) {
+ head = inode_hashtable + hash(sb,sb->s_nextino);
+ res = sb->s_nextino++;
inode = find_inode_fast(sb, head, res);
if (!inode) {
spin_unlock(&inode_lock);
return res;
}
} else {
- counter = max_reserved + 1;
+ sb->s_nextino = max_reserved + 1;
}
goto retry;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2fe6e3f..3dd0e0f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -961,6 +961,14 @@ #endif
/* Granularity of c/m/atime in ns.
Cannot be worse than a second */
u32 s_time_gran;
+
+ /* per-sb inode counter for new_inode. Make it a 32-bit counter when
+ we have the possibility of dealing with 32-bit apps */
+#ifdef CONFIG_COMPAT
+ unsigned int s_nextino;
+#else
+ unsigned long s_nextino;
+#endif
};
extern struct timespec current_fs_time(struct super_block *sb);
@@ -1712,6 +1720,7 @@ extern void __iget(struct inode * inode)
extern void clear_inode(struct inode *);
extern void destroy_inode(struct inode *);
extern struct inode *new_inode(struct super_block *);
+extern struct inode *new_inode_autonum(struct super_block *);
extern int __remove_suid(struct dentry *, int);
extern int should_remove_suid(struct dentry *);
extern int remove_suid(struct dentry *);
-
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