fs: hide file and bfile caches behind runtime const machinery

s/cachep/cache/ for consistency with namei and dentry caches.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260328173728.3388070-1-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/file.c b/fs/file.c
index 51ddcff0081a65038404b668d8813970cbc1f3b7..290ebcaea927d3998e38cdc045a8b83ef6b9e35f 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -200,7 +200,7 @@ static struct fdtable *alloc_fdtable(unsigned int slots_wanted)
        /*
         * Check if the allocation size would exceed INT_MAX. kvmalloc_array()
         * and kvmalloc() will warn if the allocation size is greater than
-        * INT_MAX, as filp_cachep objects are not __GFP_NOWARN.
+        * INT_MAX, as filp_cache objects are not __GFP_NOWARN.
         *
         * This can happen when sysctl_nr_open is set to a very high value and
         * a process tries to use a file descriptor near that limit. For example,

diff --git a/fs/file_table.c b/fs/file_table.c
index aaa5faaace1e96c3aa7bf285ad24ab823850d13d..c40ec1be289928b67b3d554c7e23db4f31c8c63c 100644 (file)
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -30,6 +30,8 @@
 
 #include <linux/atomic.h>
 
+#include <asm/runtime-const.h>
+
 #include "internal.h"
 
 /* sysctl tunables... */
@@ -38,8 +40,10 @@ static struct files_stat_struct files_stat = {
 };
 
 /* SLAB cache for file structures */
-static struct kmem_cache *filp_cachep __ro_after_init;
-static struct kmem_cache *bfilp_cachep __ro_after_init;
+static struct kmem_cache *__filp_cache __ro_after_init;
+#define filp_cache runtime_const_ptr(__filp_cache)
+static struct kmem_cache *__bfilp_cache __ro_after_init;
+#define bfilp_cache runtime_const_ptr(__bfilp_cache)
 
 static struct percpu_counter nr_files __cacheline_aligned_in_smp;
 
@@ -74,9 +78,9 @@ static inline void file_free(struct file *f)
        put_cred(f->f_cred);
        if (unlikely(f->f_mode & FMODE_BACKING)) {
                path_put(backing_file_user_path(f));
-               kmem_cache_free(bfilp_cachep, backing_file(f));
+               kmem_cache_free(bfilp_cache, backing_file(f));
        } else {
-               kmem_cache_free(filp_cachep, f);
+               kmem_cache_free(filp_cache, f);
        }
 }
 
@@ -234,13 +238,13 @@ struct file *alloc_empty_file(int flags, const struct cred *cred)
                        goto over;
        }
 
-       f = kmem_cache_alloc(filp_cachep, GFP_KERNEL);
+       f = kmem_cache_alloc(filp_cache, GFP_KERNEL);
        if (unlikely(!f))
                return ERR_PTR(-ENOMEM);
 
        error = init_file(f, flags, cred);
        if (unlikely(error)) {
-               kmem_cache_free(filp_cachep, f);
+               kmem_cache_free(filp_cache, f);
                return ERR_PTR(error);
        }
 
@@ -268,13 +272,13 @@ struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred)
        struct file *f;
        int error;
 
-       f = kmem_cache_alloc(filp_cachep, GFP_KERNEL);
+       f = kmem_cache_alloc(filp_cache, GFP_KERNEL);
        if (unlikely(!f))
                return ERR_PTR(-ENOMEM);
 
        error = init_file(f, flags, cred);
        if (unlikely(error)) {
-               kmem_cache_free(filp_cachep, f);
+               kmem_cache_free(filp_cache, f);
                return ERR_PTR(error);
        }
 
@@ -295,13 +299,13 @@ struct file *alloc_empty_backing_file(int flags, const struct cred *cred)
        struct backing_file *ff;
        int error;
 
-       ff = kmem_cache_alloc(bfilp_cachep, GFP_KERNEL);
+       ff = kmem_cache_alloc(bfilp_cache, GFP_KERNEL);
        if (unlikely(!ff))
                return ERR_PTR(-ENOMEM);
 
        error = init_file(&ff->file, flags, cred);
        if (unlikely(error)) {
-               kmem_cache_free(bfilp_cachep, ff);
+               kmem_cache_free(bfilp_cache, ff);
                return ERR_PTR(error);
        }
 
@@ -593,14 +597,17 @@ void __init files_init(void)
                .freeptr_offset = offsetof(struct file, f_freeptr),
        };
 
-       filp_cachep = kmem_cache_create("filp", sizeof(struct file), &args,
+       __filp_cache = kmem_cache_create("filp", sizeof(struct file), &args,
                                SLAB_HWCACHE_ALIGN | SLAB_PANIC |
                                SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU);
+       runtime_const_init(ptr, __filp_cache);
 
        args.freeptr_offset = offsetof(struct backing_file, bf_freeptr);
-       bfilp_cachep = kmem_cache_create("bfilp", sizeof(struct backing_file),
+       __bfilp_cache = kmem_cache_create("bfilp", sizeof(struct backing_file),
                                &args, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
                                SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU);
+       runtime_const_init(ptr, __bfilp_cache);
+
        percpu_counter_init(&nr_files, 0, GFP_KERNEL);
 }
 

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index eeb070f330bdb8ef301fadfe57ebefe1b0a01755..6a86f2e004bc2799a50fb50e17def44b9bd400fd 100644 (file)
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -973,7 +973,9 @@
                RUNTIME_CONST(shift, d_hash_shift)                      \
                RUNTIME_CONST(ptr, dentry_hashtable)                    \
                RUNTIME_CONST(ptr, __dentry_cache)                      \
-               RUNTIME_CONST(ptr, __names_cache)
+               RUNTIME_CONST(ptr, __names_cache)                       \
+               RUNTIME_CONST(ptr, __filp_cache)                        \
+               RUNTIME_CONST(ptr, __bfilp_cache)
 
 /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */
 #define KUNIT_TABLE()                                                  \