From 4f911138c8da94bcff84f1d093d28e378703c43f Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Sat, 19 Jun 2021 12:26:16 +0300 Subject: fs: add generic helper for filling statx attribute flags The immutable and append-only properties on an inode are published on the inode's i_flags and enforced by the VFS. Create a helper to fill the corresponding STATX_ATTR_ flags in the kstat structure from the inode's i_flags. Only orange was converted to use this helper. Other filesystems could use it in the future. Suggested-by: Miklos Szeredi Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- include/linux/fs.h | 1 + include/linux/stat.h | 4 ++++ 2 files changed, 5 insertions(+) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 640574294216..ae6c6c34db94 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3355,6 +3355,7 @@ extern int page_symlink(struct inode *inode, const char *symname, int len); extern const struct inode_operations page_symlink_inode_operations; extern void kfree_link(void *); void generic_fillattr(struct user_namespace *, struct inode *, struct kstat *); +void generic_fill_statx_attr(struct inode *inode, struct kstat *stat); extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int); extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int); void __inode_add_bytes(struct inode *inode, loff_t bytes); diff --git a/include/linux/stat.h b/include/linux/stat.h index fff27e603814..7df06931f25d 100644 --- a/include/linux/stat.h +++ b/include/linux/stat.h @@ -34,6 +34,10 @@ struct kstat { STATX_ATTR_ENCRYPTED | \ STATX_ATTR_VERITY \ )/* Attrs corresponding to FS_*_FL flags */ +#define KSTAT_ATTR_VFS_FLAGS \ + (STATX_ATTR_IMMUTABLE | \ + STATX_ATTR_APPEND \ + ) /* Attrs corresponding to S_* flags that are enforced by the VFS */ u64 ino; dev_t dev; dev_t rdev; -- cgit v1.2.3 From 0cad6246621b5887d5b33fea84219d2a71f2f99a Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 18 Aug 2021 22:08:24 +0200 Subject: vfs: add rcu argument to ->get_acl() callback Add a rcu argument to the ->get_acl() callback to allow get_cached_acl_rcu() to call the ->get_acl() method in the next patch. Signed-off-by: Miklos Szeredi --- include/linux/fs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index ae6c6c34db94..73376dfe28d0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2065,7 +2065,7 @@ struct inode_operations { struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *); int (*permission) (struct user_namespace *, struct inode *, int); - struct posix_acl * (*get_acl)(struct inode *, int); + struct posix_acl * (*get_acl)(struct inode *, int, bool); int (*readlink) (struct dentry *, char __user *,int); -- cgit v1.2.3 From 332f606b32b6291a944c8cf23b91f53a6e676525 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 18 Aug 2021 22:08:24 +0200 Subject: ovl: enable RCU'd ->get_acl() Overlayfs does not cache ACL's (to avoid double caching). Instead it just calls the underlying filesystem's i_op->get_acl(), which will return the cached value, if possible. In rcu path walk, however, get_cached_acl_rcu() is employed to get the value from the cache, which will fail on overlayfs resulting in dropping out of rcu walk mode. This can result in a big performance hit in certain situations. Fix by calling ->get_acl() with rcu=true in case of ACL_DONT_CACHE (which indicates pass-through) Reported-by: garyhuang Signed-off-by: Miklos Szeredi --- include/linux/fs.h | 5 +++++ include/linux/posix_acl.h | 3 ++- 2 files changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/fs.h b/include/linux/fs.h index 73376dfe28d0..c6e5bcbff0c0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -581,6 +581,11 @@ static inline void mapping_allow_writable(struct address_space *mapping) struct posix_acl; #define ACL_NOT_CACHED ((void *)(-1)) +/* + * ACL_DONT_CACHE is for stacked filesystems, that rely on underlying fs to + * cache the ACL. This also means that ->get_acl() can be called in RCU mode + * with the LOOKUP_RCU flag. + */ #define ACL_DONT_CACHE ((void *)(-3)) static inline struct posix_acl * diff --git a/include/linux/posix_acl.h b/include/linux/posix_acl.h index 307094ebb88c..b65c877d92b8 100644 --- a/include/linux/posix_acl.h +++ b/include/linux/posix_acl.h @@ -72,6 +72,8 @@ extern struct posix_acl *get_posix_acl(struct inode *, int); extern int set_posix_acl(struct user_namespace *, struct inode *, int, struct posix_acl *); +struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type); + #ifdef CONFIG_FS_POSIX_ACL int posix_acl_chmod(struct user_namespace *, struct inode *, umode_t); extern int posix_acl_create(struct inode *, umode_t *, struct posix_acl **, @@ -84,7 +86,6 @@ extern int simple_set_acl(struct user_namespace *, struct inode *, extern int simple_acl_create(struct inode *, struct inode *); struct posix_acl *get_cached_acl(struct inode *inode, int type); -struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type); void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl); void forget_cached_acl(struct inode *inode, int type); void forget_all_cached_acls(struct inode *inode); -- cgit v1.2.3