From: Chao Yu Date: Tue, 21 Oct 2025 03:48:56 +0000 (+0800) Subject: f2fs: use global inline_xattr_slab instead of per-sb slab cache X-Git-Tag: v6.19-rc1~48^2~27 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1f27ef42bb0b7c0740c5616ec577ec188b8a1d05;p=thirdparty%2Flinux.git f2fs: use global inline_xattr_slab instead of per-sb slab cache As Hong Yun reported in mailing list: loop7: detected capacity change from 0 to 131072 ------------[ cut here ]------------ kmem_cache of name 'f2fs_xattr_entry-7:7' already exists WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 kmem_cache_sanity_check mm/slab_common.c:109 [inline] WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 __kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307 CPU: 0 UID: 0 PID: 24426 Comm: syz.7.1370 Not tainted 6.17.0-rc4 #1 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:109 [inline] RIP: 0010:__kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307 Call Trace:  __kmem_cache_create include/linux/slab.h:353 [inline]  f2fs_kmem_cache_create fs/f2fs/f2fs.h:2943 [inline]  f2fs_init_xattr_caches+0xa5/0xe0 fs/f2fs/xattr.c:843  f2fs_fill_super+0x1645/0x2620 fs/f2fs/super.c:4918  get_tree_bdev_flags+0x1fb/0x260 fs/super.c:1692  vfs_get_tree+0x43/0x140 fs/super.c:1815  do_new_mount+0x201/0x550 fs/namespace.c:3808  do_mount fs/namespace.c:4136 [inline]  __do_sys_mount fs/namespace.c:4347 [inline]  __se_sys_mount+0x298/0x2f0 fs/namespace.c:4324  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]  do_syscall_64+0x8e/0x3a0 arch/x86/entry/syscall_64.c:94  entry_SYSCALL_64_after_hwframe+0x76/0x7e The bug can be reproduced w/ below scripts: - mount /dev/vdb /mnt1 - mount /dev/vdc /mnt2 - umount /mnt1 - mounnt /dev/vdb /mnt1 The reason is if we created two slab caches, named f2fs_xattr_entry-7:3 and f2fs_xattr_entry-7:7, and they have the same slab size. Actually, slab system will only create one slab cache core structure which has slab name of "f2fs_xattr_entry-7:3", and two slab caches share the same structure and cache address. So, if we destroy f2fs_xattr_entry-7:3 cache w/ cache address, it will decrease reference count of slab cache, rather than release slab cache entirely, since there is one more user has referenced the cache. Then, if we try to create slab cache w/ name "f2fs_xattr_entry-7:3" again, slab system will find that there is existed cache which has the same name and trigger the warning. Let's changes to use global inline_xattr_slab instead of per-sb slab cache for fixing. Fixes: a999150f4fe3 ("f2fs: use kmem_cache pool during inline xattr lookups") Cc: stable@kernel.org Reported-by: Hong Yun Tested-by: Hong Yun Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index e69b01c1173ad..9ca2124aac84d 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1885,9 +1885,6 @@ struct f2fs_sb_info { spinlock_t error_lock; /* protect errors/stop_reason array */ bool error_dirty; /* errors of sb is dirty */ - struct kmem_cache *inline_xattr_slab; /* inline xattr entry */ - unsigned int inline_xattr_slab_size; /* default inline xattr slab size */ - /* For reclaimed segs statistics per each GC mode */ unsigned int gc_segment_mode; /* GC state for reclaimed segments */ unsigned int gc_reclaimed_segs[MAX_GC_MODE]; /* Reclaimed segs for each mode */ diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index d0b5791a1f8cb..f76ba2b08be02 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2027,7 +2027,6 @@ static void f2fs_put_super(struct super_block *sb) kfree(sbi->raw_super); f2fs_destroy_page_array_cache(sbi); - f2fs_destroy_xattr_caches(sbi); #ifdef CONFIG_QUOTA for (i = 0; i < MAXQUOTAS; i++) kfree(F2FS_OPTION(sbi).s_qf_names[i]); @@ -4975,13 +4974,9 @@ try_onemore: if (err) goto free_iostat; - /* init per sbi slab cache */ - err = f2fs_init_xattr_caches(sbi); - if (err) - goto free_percpu; err = f2fs_init_page_array_cache(sbi); if (err) - goto free_xattr_cache; + goto free_percpu; /* get an inode for meta space */ sbi->meta_inode = f2fs_iget(sb, F2FS_META_INO(sbi)); @@ -5310,8 +5305,6 @@ free_meta_inode: sbi->meta_inode = NULL; free_page_array_cache: f2fs_destroy_page_array_cache(sbi); -free_xattr_cache: - f2fs_destroy_xattr_caches(sbi); free_percpu: destroy_percpu_info(sbi); free_iostat: @@ -5514,10 +5507,15 @@ static int __init init_f2fs_fs(void) err = f2fs_create_casefold_cache(); if (err) goto free_compress_cache; - err = register_filesystem(&f2fs_fs_type); + err = f2fs_init_xattr_cache(); if (err) goto free_casefold_cache; + err = register_filesystem(&f2fs_fs_type); + if (err) + goto free_xattr_cache; return 0; +free_xattr_cache: + f2fs_destroy_xattr_cache(); free_casefold_cache: f2fs_destroy_casefold_cache(); free_compress_cache: @@ -5558,6 +5556,7 @@ fail: static void __exit exit_f2fs_fs(void) { unregister_filesystem(&f2fs_fs_type); + f2fs_destroy_xattr_cache(); f2fs_destroy_casefold_cache(); f2fs_destroy_compress_cache(); f2fs_destroy_compress_mempool(); diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c index 58632a2b66136..b4e5c406632f8 100644 --- a/fs/f2fs/xattr.c +++ b/fs/f2fs/xattr.c @@ -23,11 +23,12 @@ #include "xattr.h" #include "segment.h" +static struct kmem_cache *inline_xattr_slab; static void *xattr_alloc(struct f2fs_sb_info *sbi, int size, bool *is_inline) { - if (likely(size == sbi->inline_xattr_slab_size)) { + if (likely(size == DEFAULT_XATTR_SLAB_SIZE)) { *is_inline = true; - return f2fs_kmem_cache_alloc(sbi->inline_xattr_slab, + return f2fs_kmem_cache_alloc(inline_xattr_slab, GFP_F2FS_ZERO, false, sbi); } *is_inline = false; @@ -38,7 +39,7 @@ static void xattr_free(struct f2fs_sb_info *sbi, void *xattr_addr, bool is_inline) { if (is_inline) - kmem_cache_free(sbi->inline_xattr_slab, xattr_addr); + kmem_cache_free(inline_xattr_slab, xattr_addr); else kfree(xattr_addr); } @@ -830,25 +831,14 @@ int f2fs_setxattr(struct inode *inode, int index, const char *name, return err; } -int f2fs_init_xattr_caches(struct f2fs_sb_info *sbi) +int __init f2fs_init_xattr_cache(void) { - dev_t dev = sbi->sb->s_bdev->bd_dev; - char slab_name[32]; - - sprintf(slab_name, "f2fs_xattr_entry-%u:%u", MAJOR(dev), MINOR(dev)); - - sbi->inline_xattr_slab_size = F2FS_OPTION(sbi).inline_xattr_size * - sizeof(__le32) + XATTR_PADDING_SIZE; - - sbi->inline_xattr_slab = f2fs_kmem_cache_create(slab_name, - sbi->inline_xattr_slab_size); - if (!sbi->inline_xattr_slab) - return -ENOMEM; - - return 0; + inline_xattr_slab = f2fs_kmem_cache_create("f2fs_xattr_entry", + DEFAULT_XATTR_SLAB_SIZE); + return inline_xattr_slab ? 0 : -ENOMEM; } -void f2fs_destroy_xattr_caches(struct f2fs_sb_info *sbi) +void f2fs_destroy_xattr_cache(void) { - kmem_cache_destroy(sbi->inline_xattr_slab); -} + kmem_cache_destroy(inline_xattr_slab); +} \ No newline at end of file diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h index 4fc0b2305fbd8..bce3d93e4755b 100644 --- a/fs/f2fs/xattr.h +++ b/fs/f2fs/xattr.h @@ -89,6 +89,8 @@ struct f2fs_xattr_entry { F2FS_TOTAL_EXTRA_ATTR_SIZE / sizeof(__le32) - \ DEF_INLINE_RESERVED_SIZE - \ MIN_INLINE_DENTRY_SIZE / sizeof(__le32)) +#define DEFAULT_XATTR_SLAB_SIZE (DEFAULT_INLINE_XATTR_ADDRS * \ + sizeof(__le32) + XATTR_PADDING_SIZE) /* * On-disk structure of f2fs_xattr @@ -132,8 +134,8 @@ int f2fs_setxattr(struct inode *, int, const char *, const void *, int f2fs_getxattr(struct inode *, int, const char *, void *, size_t, struct folio *); ssize_t f2fs_listxattr(struct dentry *, char *, size_t); -int f2fs_init_xattr_caches(struct f2fs_sb_info *); -void f2fs_destroy_xattr_caches(struct f2fs_sb_info *); +int __init f2fs_init_xattr_cache(void); +void f2fs_destroy_xattr_cache(void); #else #define f2fs_xattr_handlers NULL @@ -150,8 +152,8 @@ static inline int f2fs_getxattr(struct inode *inode, int index, { return -EOPNOTSUPP; } -static inline int f2fs_init_xattr_caches(struct f2fs_sb_info *sbi) { return 0; } -static inline void f2fs_destroy_xattr_caches(struct f2fs_sb_info *sbi) { } +static inline int __init f2fs_init_xattr_cache(void) { return 0; } +static inline void f2fs_destroy_xattr_cache(void) { } #endif #ifdef CONFIG_F2FS_FS_SECURITY