From c3a3577cdb351e74d6ff6bc328c3bee18ce69298 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 19 Nov 2025 19:19:24 -0500 Subject: struct filename: use names_cachep only for getname() and friends Instances of struct filename come from names_cachep (via __getname()). That is done by getname_flags() and getname_kernel() and these two are the main callers of __getname(). However, there are other callers that simply want to allocate PATH_MAX bytes for uses that have nothing to do with struct filename. We want saner allocation rules for long pathnames, so that struct filename would *always* come from names_cachep, with the out-of-line pathname getting kmalloc'ed. For that we need to be able to change the size of objects allocated by getname_flags()/getname_kernel(). That requires the rest of __getname() users to stop using names_cachep; we could explicitly switch all of those to kmalloc(), but that would cause quite a bit of noise. So the plan is to switch getname_...() to new helpers and turn __getname() into a wrapper for kmalloc(). Remaining __getname() users could be converted to explicit kmalloc() at leisure, hopefully along with figuring out what size do they really want - PATH_MAX is an overkill for some of them, used out of laziness ("we have a convenient helper that does 4K allocations and that's large enough, let's use it"). As a side benefit, names_cachep is no longer used outside of fs/namei.c, so we can move it there and be done with that. Signed-off-by: Al Viro --- include/linux/fs.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index abe9c95c4874..997d515bab32 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2539,10 +2539,8 @@ static inline int finish_open_simple(struct file *file, int error) extern void __init vfs_caches_init_early(void); extern void __init vfs_caches_init(void); -extern struct kmem_cache *names_cachep; - -#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) -#define __putname(name) kmem_cache_free(names_cachep, (void *)(name)) +#define __getname() kmalloc(PATH_MAX, GFP_KERNEL) +#define __putname(name) kfree(name) void emergency_thaw_all(void); extern int sync_filesystem(struct super_block *); -- cgit v1.2.3