1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/file.h>
6 #include <linux/swap.h>
7 #include <linux/mempolicy.h>
8 #include <linux/pagemap.h>
9 #include <linux/percpu_counter.h>
10 #include <linux/xattr.h>
11 #include <linux/fs_parser.h>
13 /* inode in-kernel data */
15 struct shmem_inode_info
{
17 unsigned int seals
; /* shmem seals */
19 unsigned long alloced
; /* data pages alloced to file */
20 unsigned long swapped
; /* subtotal assigned to swap */
21 struct list_head shrinklist
; /* shrinkable hpage inodes */
22 struct list_head swaplist
; /* chain of maybes on swap */
23 struct shared_policy policy
; /* NUMA memory alloc policy */
24 struct simple_xattrs xattrs
; /* list of xattrs */
25 atomic_t stop_eviction
; /* hold when working on inode */
26 struct inode vfs_inode
;
29 struct shmem_sb_info
{
30 struct mutex idr_lock
;
32 struct idr idr
; /* manages inode-number */
33 unsigned long max_blocks
; /* How many blocks are allowed */
34 struct percpu_counter used_blocks
; /* How many are allocated */
35 int max_inodes
; /* How many inodes are allowed */
36 int free_inodes
; /* How many are left for allocation */
37 spinlock_t stat_lock
; /* Serialize shmem_sb_info changes */
38 umode_t mode
; /* Mount mode for root directory */
39 unsigned char huge
; /* Whether to try for hugepages */
40 kuid_t uid
; /* Mount uid for root directory */
41 kgid_t gid
; /* Mount gid for root directory */
42 bool full_inums
; /* If i_ino should be uint or ino_t */
43 ino_t next_ino
; /* The next per-sb inode number to use */
44 ino_t __percpu
*ino_batch
; /* The next per-cpu inode number to use */
45 struct mempolicy
*mpol
; /* default memory policy for mappings */
46 spinlock_t shrinklist_lock
; /* Protects shrinklist */
47 struct list_head shrinklist
; /* List of shinkable inodes */
48 unsigned long shrinklist_len
; /* Length of shrinklist */
51 static inline struct shmem_inode_info
*SHMEM_I(struct inode
*inode
)
53 return container_of(inode
, struct shmem_inode_info
, vfs_inode
);
57 * Functions in mm/shmem.c called directly from elsewhere:
59 extern const struct fs_parameter_spec shmem_fs_parameters
[];
60 extern int shmem_init(void);
61 extern int shmem_init_fs_context(struct fs_context
*fc
);
62 extern struct file
*shmem_file_setup(const char *name
,
63 loff_t size
, unsigned long flags
);
64 extern struct file
*shmem_kernel_file_setup(const char *name
, loff_t size
,
66 extern struct file
*shmem_file_setup_with_mnt(struct vfsmount
*mnt
,
67 const char *name
, loff_t size
, unsigned long flags
);
68 extern int shmem_zero_setup(struct vm_area_struct
*);
69 extern unsigned long shmem_get_unmapped_area(struct file
*, unsigned long addr
,
70 unsigned long len
, unsigned long pgoff
, unsigned long flags
);
71 extern int shmem_lock(struct file
*file
, int lock
, struct user_struct
*user
);
73 extern bool shmem_mapping(struct address_space
*mapping
);
75 static inline bool shmem_mapping(struct address_space
*mapping
)
79 #endif /* CONFIG_SHMEM */
80 extern void shmem_unlock_mapping(struct address_space
*mapping
);
81 extern struct page
*shmem_read_mapping_page_gfp(struct address_space
*mapping
,
82 pgoff_t index
, gfp_t gfp_mask
);
83 extern void shmem_truncate_range(struct inode
*inode
, loff_t start
, loff_t end
);
84 extern int shmem_unuse(unsigned int type
, bool frontswap
,
85 unsigned long *fs_pages_to_unuse
);
87 extern bool shmem_huge_enabled(struct vm_area_struct
*vma
);
88 extern unsigned long shmem_swap_usage(struct vm_area_struct
*vma
);
89 extern unsigned long shmem_partial_swap_usage(struct address_space
*mapping
,
90 pgoff_t start
, pgoff_t end
);
92 /* Flag allocation requirements to shmem_getpage */
94 SGP_READ
, /* don't exceed i_size, don't allocate page */
95 SGP_CACHE
, /* don't exceed i_size, may allocate page */
96 SGP_NOHUGE
, /* like SGP_CACHE, but no huge pages */
97 SGP_HUGE
, /* like SGP_CACHE, huge pages preferred */
98 SGP_WRITE
, /* may exceed i_size, may allocate !Uptodate page */
99 SGP_FALLOC
, /* like SGP_WRITE, but make existing page Uptodate */
102 extern int shmem_getpage(struct inode
*inode
, pgoff_t index
,
103 struct page
**pagep
, enum sgp_type sgp
);
105 static inline struct page
*shmem_read_mapping_page(
106 struct address_space
*mapping
, pgoff_t index
)
108 return shmem_read_mapping_page_gfp(mapping
, index
,
109 mapping_gfp_mask(mapping
));
112 static inline bool shmem_file(struct file
*file
)
114 if (!IS_ENABLED(CONFIG_SHMEM
))
116 if (!file
|| !file
->f_mapping
)
118 return shmem_mapping(file
->f_mapping
);
121 extern bool shmem_charge(struct inode
*inode
, long pages
);
122 extern void shmem_uncharge(struct inode
*inode
, long pages
);
125 extern int shmem_mcopy_atomic_pte(struct mm_struct
*dst_mm
, pmd_t
*dst_pmd
,
126 struct vm_area_struct
*dst_vma
,
127 unsigned long dst_addr
,
128 unsigned long src_addr
,
129 struct page
**pagep
);
130 extern int shmem_mfill_zeropage_pte(struct mm_struct
*dst_mm
,
132 struct vm_area_struct
*dst_vma
,
133 unsigned long dst_addr
);
135 #define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
136 src_addr, pagep) ({ BUG(); 0; })
137 #define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
138 dst_addr) ({ BUG(); 0; })