MAJOR=4
MINOR=21
DEVNAME=tty21
      =ˆÅË0a–Ým_J*j"Tâ€rãA¸'TÅ£É     ?ˆÍÌƒuÇË¾É ð    ?/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SHMEM_FS_H
#define __SHMEM_FS_H

#include <linux/file.h>
#include <linux/swap.h>
#include <linux/mempolicy.h>
#include <linux/pagemap.h>
#include <linux/percpu_counter.h>
#include <linux/xattr.h>
#include <linux/fs_parser.h>
#include <linux/userfaultfd_k.h>

/* inode in-kernel data */

#ifdef CONFIG_TMPFS_QUOTA
#define SHMEM_MAXQUOTAS 2
#endif

struct shmem_inode_info {
	spinlock_t		lock;
	unsigned int		seals;		/* shmem seals */
	unsigned long		flags;
	unsigned long		alloced;	/* data pages alloced to file */
	unsigned long		swapped;	/* subtotal assigned to swap */
	union {
	    struct {
	        struct list_head shrinklist;	/* shrinkable hpage inodes */
	        struct list_head swaplist;	/* chain of maybes on swap */
	    };
	};
	struct timespec64	i_crtime;	/* file creation time */
	struct shared_policy	policy;		/* NUMA memory alloc policy */
	struct simple_xattrs	xattrs;		/* list of xattrs */
	pgoff_t			fallocend;	/* highest fallocate endindex */
	unsigned int		fsflags;	/* flags for FS_IOC_[SG]ETFLAGS */
	atomic_t		stop_eviction;	/* hold when working on inode */
#ifdef CONFIG_TMPFS_QUOTA
	struct dquot		*i_dquot[MAXQUOTAS];
#endif
	struct inode		vfs_inode;
};

#define SHMEM_FL_USER_VISIBLE		FS_FL_USER_VISIBLE
#define SHMEM_FL_USER_MODIFIABLE \
	(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
#define SHMEM_FL_INHERITED		(FS_NODUMP_FL | FS_NOATIME_FL)

struct shmem_quota_limits {
	qsize_t usrquota_bhardlimit; /* Default user quota block hard limit */
	qsize_t usrquota_ihardlimit; /* Default user quota inode hard limit */
	qsize_t grpquota_bhardlimit; /* Default group quota block hard limit */
	qsize_t grpquota_ihardlimit; /* Default group quota inode hard limit */
};

struct shmem_sb_info {
	unsigned long max_blocks;   /* How many blocks are allowed */
	struct percpu_counter used_blocks;  /* How many are allocated */
	unsigned long max_inodes;   /* How many inodes are allowed */
	unsigned long free_ispace;  /* How much ispace left for allocation */
	raw_spinlock_t stat_lock;   /* Serialize shmem_sb_info changes */
	umode_t mode;		    /* Mount mode for root directory */
	unsigned char huge;	    /* Whether to try for hugepages */
	kuid_t uid;		    /* Mount uid for root directory */
	kgid_t gid;		    /* Mount gid for root directory */
	bool full_inums;	    /* If i_ino should be uint or ino_t */
	bool noswap;		    /* ignores VM reclaim / swap requests */
	ino_t next_ino;		    /* The next per-sb inode number to use */
	ino_t __percpu *ino_batch;  /* The next per-cpu inode number to use */
	struct mempolicy *mpol;     /* default memory policy for mappings */
	spinlock_t shrinklist_lock;   /* Protects shrinklist */
	struct list_head shrinklist;  /* List of shinkable inodes */
	unsigned long shrinklist_len; /* Length of shrinklist */
	struct shmem_quota_limits qlimits; /* Default quota limits */
};

static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
{
	return container_of(inode, struct shmem_inode_info, vfs_inode);
}

/*
 * Functions in mm/shmem.c called directly from elsewhere:
 */
extern const struct fs_parameter_spec shmem_fs_parameters[];
extern void shmem_init(void);
extern int shmem_init_fs_context(struct fs_context *fc);
extern struct file *shmem_file_setup(const char *name,
					loff_t size, unsigned long flags);
extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
					    unsigned long flags);
extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt,
		const char *name, loff_t size, unsigned long flags);
extern int shmem_zero_setup(struct vm_area_struct *);
extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
		unsigned long len, unsigned long pgoff, unsigned long flags);
extern int shmem_lock(struct file *file, int lock, struct ucounts *ucounts);
#ifdef CONFIG_SHMEM
bool shmem_mapping(struct address_space *mapping);
#else
static inline bool shmem_mapping(struct address_space *mapp