xref: /linux-6.15/include/linux/shmem_fs.h (revision bcefe12e)
1 #ifndef __SHMEM_FS_H
2 #define __SHMEM_FS_H
3 
4 #include <linux/swap.h>
5 #include <linux/mempolicy.h>
6 
7 /* inode in-kernel data */
8 
9 #define SHMEM_NR_DIRECT 16
10 
11 struct shmem_inode_info {
12 	spinlock_t		lock;
13 	unsigned long		flags;
14 	unsigned long		alloced;	/* data pages alloced to file */
15 	unsigned long		swapped;	/* subtotal assigned to swap */
16 	unsigned long		next_index;	/* highest alloced index + 1 */
17 	struct shared_policy	policy;		/* NUMA memory alloc policy */
18 	struct page		*i_indirect;	/* top indirect blocks page */
19 	swp_entry_t		i_direct[SHMEM_NR_DIRECT]; /* first blocks */
20 	struct list_head	swaplist;	/* chain of maybes on swap */
21 	struct inode		vfs_inode;
22 };
23 
24 struct shmem_sb_info {
25 	unsigned long max_blocks;   /* How many blocks are allowed */
26 	unsigned long free_blocks;  /* How many are left for allocation */
27 	unsigned long max_inodes;   /* How many inodes are allowed */
28 	unsigned long free_inodes;  /* How many are left for allocation */
29 	spinlock_t stat_lock;	    /* Serialize shmem_sb_info changes */
30 	uid_t uid;		    /* Mount uid for root directory */
31 	gid_t gid;		    /* Mount gid for root directory */
32 	mode_t mode;		    /* Mount mode for root directory */
33 	struct mempolicy *mpol;     /* default memory policy for mappings */
34 };
35 
36 static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
37 {
38 	return container_of(inode, struct shmem_inode_info, vfs_inode);
39 }
40 
41 extern int init_tmpfs(void);
42 extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
43 
44 #ifdef CONFIG_TMPFS_POSIX_ACL
45 int shmem_check_acl(struct inode *, int);
46 int shmem_acl_init(struct inode *, struct inode *);
47 
48 extern struct xattr_handler shmem_xattr_acl_access_handler;
49 extern struct xattr_handler shmem_xattr_acl_default_handler;
50 
51 extern struct generic_acl_operations shmem_acl_ops;
52 
53 #else
54 static inline int shmem_acl_init(struct inode *inode, struct inode *dir)
55 {
56 	return 0;
57 }
58 #endif  /* CONFIG_TMPFS_POSIX_ACL */
59 
60 #endif
61