[PATCH RFC v2 2/3] pidfs: remove 32bit inode number handling

Christian Brauner
2024-11-29T13:02:46Z

Now that we have a unified inode number handling model remove the custom
ida-based allocation for 32bit.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/pidfs.c | 46 +++++-----------------------------------------
1 file changed, 5 insertions(+), 41 deletions(-)

diff --git a/fs/pidfs.c b/fs/pidfs.c
index 0bdd9c525b80895d33f2eae5e8e375788580072f..ff4f25078f3d983bce630e597adbb12262e5d727 100644
--- a/fs/pidfs.c
+++ b/fs/pidfs.c
@@ -371,40 +371,6 @@ struct pid *pidfd_pid(const struct file *file)

static struct vfsmount *pidfs_mnt __ro_after_init;

-#if BITS_PER_LONG == 32
-/*
- * Provide a fallback mechanism for 32-bit systems so processes remain
- * reliably comparable by inode number even on those systems.
- */
-static DEFINE_IDA(pidfd_inum_ida);
-
-static int pidfs_inum(struct pid *pid, unsigned long *ino)
-{
- int ret;
-
- ret = ida_alloc_range(&pidfd_inum_ida, RESERVED_PIDS + 1,
- UINT_MAX, GFP_ATOMIC);
- if (ret < 0)
- return -ENOSPC;
-
- *ino = ret;
- return 0;
-}
-
-static inline void pidfs_free_inum(unsigned long ino)
-{
- if (ino > 0)
- ida_free(&pidfd_inum_ida, ino);
-}
-#else
-static inline int pidfs_inum(struct pid *pid, unsigned long *ino)
-{
- *ino = pid->ino;
- return 0;
-}
-#define pidfs_free_inum(ino) ((void)(ino))
-#endif
-
/*
* The vfs falls back to simple_setattr() if i_op->setattr() isn't
* implemented. Let's reject it completely until we have a clean
@@ -456,7 +422,6 @@ static void pidfs_evict_inode(struct inode *inode)

clear_inode(inode);
put_pid(pid);
- pidfs_free_inum(inode->i_ino);
}

static const struct super_operations pidfs_sops = {
@@ -482,17 +447,16 @@ static const struct dentry_operations pidfs_dentry_operations = {

static int pidfs_init_inode(struct inode *inode, void *data)
{
+ struct pid *pid = data;
+
inode->i_private = data;
inode->i_flags |= S_PRIVATE;
inode->i_mode |= S_IRWXU;
inode->i_op = &pidfs_inode_operations;
inode->i_fop = &pidfs_file_operations;
- /*
- * Inode numbering for pidfs start at RESERVED_PIDS + 1. This
- * avoids collisions with the root inode which is 1 for pseudo
- * filesystems.
- */
- return pidfs_inum(data, &inode->i_ino);
+ inode->i_ino = pidfs_ino(pid->ino);
+ inode->i_generation = pidfs_gen(pid->ino);
+ return 0;
}

static void pidfs_put_data(void *data)

--
2.45.2