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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/* 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 */
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 */
pgoff_t fallocend; /* highest fallocate endindex */
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 */
atomic_t stop_eviction; /* hold when working on inode */
struct timespec64 i_crtime; /* file creation time */
unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */
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_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 */
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 */
};
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
extern const struct address_space_operations shmem_aops;
static inline bool shmem_mapping(struct address_space *mapping)
{
return mapping->a_ops == &shmem_aops;
}
#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);
int shmem_unuse(unsigned int type);
extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
struct mm_struct *mm, unsigned long vm_flags);
#ifdef CONFIG_SHMEM
extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
#else
static inline unsigned long shmem_swap_usage(struct vm_area_struct *vma)
{
return 0;
}
#endif
extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
pgoff_t start, pgoff_t end);
/* Flag allocation requirements to shmem_get_folio */
enum sgp_type {
SGP_READ, /* don't exceed i_size, don't allocate page */
SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */
SGP_CACHE, /* don't exceed i_size, may allocate page */
SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
};
int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
enum sgp_type sgp);
struct folio *shmem_read_folio_gfp(struct address_space *mapping,
pgoff_t index, gfp_t gfp);
static inline struct folio *shmem_read_folio(struct address_space *mapping,
pgoff_t index)
{
return shmem_read_folio_gfp(mapping, index, mapping_gfp_mask(mapping));
}
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);
}
/*
* If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages
* beyond i_size's notion of EOF, which fallocate has committed to reserving:
* which split_huge_page() must therefore not delete. This use of a single
* "fallocend" per inode errs on the side of not deleting a reservation when
* in doubt: there are plenty of cases when it preserves unreserved pages.
*/
static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof)
{
return max(eof, SHMEM_I(inode)->fallocend);
}
extern bool shmem_charge(struct inode *inode, long pages);
extern void shmem_uncharge(struct inode *inode, long pages);
#ifdef CONFIG_USERFAULTFD
#ifdef CONFIG_SHMEM
extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
uffd_flags_t flags,
struct page **pagep);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \
src_addr, flags, pagep) ({ BUG(); 0; })
#endif /* CONFIG_SHMEM */
#endif /* CONFIG_USERFAULTFD */
#endif
|
