Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: ed91ce57c428da1632c7696e8b75fb0bf88941c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/* 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>

/* inode in-kernel data */

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 */
	struct list_head        shrinklist;     /* shrinkable hpage inodes */
	struct list_head	swaplist;	/* chain of maybes on swap */
	struct shared_policy	policy;		/* NUMA memory alloc policy */
	struct simple_xattrs	xattrs;		/* list of xattrs */
	struct inode		vfs_inode;
};

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_inodes;  /* How many are left for allocation */
	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 */
	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 */
};

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 int shmem_init(void);
extern int shmem_fill_super(struct super_block *sb, void *data, int silent);
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 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 user_struct *user);
#ifdef CONFIG_SHMEM
extern bool shmem_mapping(struct address_space *mapping);
#else
static inline bool shmem_mapping(struct address_space *mapping)
{
	return false;
}
#endif /* CONFIG_SHMEM */
extern void shmem_unlock_mapping(struct address_space *mapping);
extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
					pgoff_t index, gfp_t gfp_mask);
extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
extern int shmem_unuse(swp_entry_t entry, struct page *page);

extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
						pgoff_t start, pgoff_t end);

/* Flag allocation requirements to shmem_getpage */
enum sgp_type {
	SGP_READ,	/* don't exceed i_size, don't allocate page */
	SGP_CACHE,	/* don't exceed i_size, may allocate page */
	SGP_NOHUGE,	/* like SGP_CACHE, but no huge pages */
	SGP_HUGE,	/* like SGP_CACHE, huge pages preferred */
	SGP_WRITE,	/* may exceed i_size, may allocate !Uptodate page */
	SGP_FALLOC,	/* like SGP_WRITE, but make existing page Uptodate */
};

extern int shmem_getpage(struct inode *inode, pgoff_t index,
		struct page **pagep, enum sgp_type sgp);

static inline struct page *shmem_read_mapping_page(
				struct address_space *mapping, pgoff_t index)
{
	return shmem_read_mapping_page_gfp(mapping, index,
					mapping_gfp_mask(mapping));
}

static inline bool shmem_file(struct file *file)
{
	if (!IS_ENABLED(CONFIG_SHMEM))
		return false;
	if (!file || !file->f_mapping)
		return false;
	return shmem_mapping(file->f_mapping);
}

extern bool shmem_charge(struct inode *inode, long pages);
extern void shmem_uncharge(struct inode *inode, long pages);

#ifdef CONFIG_TMPFS

extern int shmem_add_seals(struct file *file, unsigned int seals);
extern int shmem_get_seals(struct file *file);
extern long shmem_fcntl(struct file *file, unsigned int cmd, unsigned long arg);

#else

static inline long shmem_fcntl(struct file *f, unsigned int c, unsigned long a)
{
	return -EINVAL;
}

#endif

#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
extern bool shmem_huge_enabled(struct vm_area_struct *vma);
#else
static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
{
	return false;
}
#endif

#ifdef CONFIG_SHMEM
extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
				  struct vm_area_struct *dst_vma,
				  unsigned long dst_addr,
				  unsigned long src_addr,
				  struct page **pagep);
extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm,
				    pmd_t *dst_pmd,
				    struct vm_area_struct *dst_vma,
				    unsigned long dst_addr);
#else
#define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
			       src_addr, pagep)        ({ BUG(); 0; })
#define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
				 dst_addr)      ({ BUG(); 0; })
#endif

#endif