[linux-block.git] / include / linux / shmem_fs.h

/* 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 */
	atomic_t		stop_eviction;	/* hold when working on inode */
	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 const struct fs_parameter_description shmem_fs_parameters;
extern int 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 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(unsigned int type, bool frontswap,
		       unsigned long *fs_pages_to_unuse);

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_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
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	#ifndef __SHMEM_FS_H
	3	#define __SHMEM_FS_H
	4
40e041a2	5	#include <linux/file.h>
1da177e4 LT	6	#include <linux/swap.h>
1da177e4 LT	7	#include <linux/mempolicy.h>
d9d90e5e	8	#include <linux/pagemap.h>
7e496299	9	#include <linux/percpu_counter.h>
38f38657	10	#include <linux/xattr.h>
1da177e4 LT	11
	12	/* inode in-kernel data */
	13
1da177e4 LT	14	struct shmem_inode_info {
1da177e4 LT	15	spinlock_t lock;
40e041a2	16	unsigned int seals; /* shmem seals */
1da177e4 LT	17	unsigned long flags;
1da177e4 LT	18	unsigned long alloced; /* data pages alloced to file */
3ed47db3	19	unsigned long swapped; /* subtotal assigned to swap */
779750d2	20	struct list_head shrinklist; /* shrinkable hpage inodes */
1da177e4	21	struct list_head swaplist; /* chain of maybes on swap */
779750d2	22	struct shared_policy policy; /* NUMA memory alloc policy */
38f38657	23	struct simple_xattrs xattrs; /* list of xattrs */
af53d3e9	24	atomic_t stop_eviction; /* hold when working on inode */
1da177e4 LT	25	struct inode vfs_inode;
	26	};
	27
	28	struct shmem_sb_info {
	29	unsigned long max_blocks; /* How many blocks are allowed */
7e496299	30	struct percpu_counter used_blocks; /* How many are allocated */
1da177e4 LT	31	unsigned long max_inodes; /* How many inodes are allowed */
1da177e4 LT	32	unsigned long free_inodes; /* How many are left for allocation */
680d794b	33	spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
5a6e75f8 KS	34	umode_t mode; /* Mount mode for root directory */
5a6e75f8 KS	35	unsigned char huge; /* Whether to try for hugepages */
8751e039 EB	36	kuid_t uid; /* Mount uid for root directory */
8751e039 EB	37	kgid_t gid; /* Mount gid for root directory */
71fe804b	38	struct mempolicy mpol; / default memory policy for mappings */
779750d2 KS	39	spinlock_t shrinklist_lock; /* Protects shrinklist */
	40	struct list_head shrinklist; /* List of shinkable inodes */
	41	unsigned long shrinklist_len; /* Length of shrinklist */
1da177e4 LT	42	};
	43
	44	static inline struct shmem_inode_info SHMEM_I(struct inode inode)
	45	{
	46	return container_of(inode, struct shmem_inode_info, vfs_inode);
	47	}
	48
072441e2 HD	49	/*
	50	* Functions in mm/shmem.c called directly from elsewhere:
	51	*/
f3235626	52	extern const struct fs_parameter_description shmem_fs_parameters;
41ffe5d5	53	extern int shmem_init(void);
f3235626	54	extern int shmem_init_fs_context(struct fs_context *fc);
072441e2 HD	55	extern struct file shmem_file_setup(const char name,
072441e2 HD	56	loff_t size, unsigned long flags);
c7277090 EP	57	extern struct file shmem_kernel_file_setup(const char name, loff_t size,
c7277090 EP	58	unsigned long flags);
703321b6 MA	59	extern struct file shmem_file_setup_with_mnt(struct vfsmount mnt,
703321b6 MA	60	const char *name, loff_t size, unsigned long flags);
072441e2	61	extern int shmem_zero_setup(struct vm_area_struct *);
c01d5b30 HD	62	extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
c01d5b30 HD	63	unsigned long len, unsigned long pgoff, unsigned long flags);
072441e2	64	extern int shmem_lock(struct file file, int lock, struct user_struct user);
3a4f8a0b	65	#ifdef CONFIG_SHMEM
0cd6144a	66	extern bool shmem_mapping(struct address_space *mapping);
3a4f8a0b HD	67	#else
	68	static inline bool shmem_mapping(struct address_space *mapping)
	69	{
	70	return false;
	71	}
	72	#endif /* CONFIG_SHMEM */
24513264	73	extern void shmem_unlock_mapping(struct address_space *mapping);
d9d90e5e HD	74	extern struct page shmem_read_mapping_page_gfp(struct address_space mapping,
d9d90e5e HD	75	pgoff_t index, gfp_t gfp_mask);
94c1e62d	76	extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
b56a2d8a VRP	77	extern int shmem_unuse(unsigned int type, bool frontswap,
b56a2d8a VRP	78	unsigned long *fs_pages_to_unuse);
2b2af54a	79
6a15a370	80	extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
48131e03 VB	81	extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
48131e03 VB	82	pgoff_t start, pgoff_t end);
6a15a370	83
f3f0e1d2 KS	84	/* Flag allocation requirements to shmem_getpage */
	85	enum sgp_type {
	86	SGP_READ, /* don't exceed i_size, don't allocate page */
	87	SGP_CACHE, /* don't exceed i_size, may allocate page */
	88	SGP_NOHUGE, /* like SGP_CACHE, but no huge pages */
	89	SGP_HUGE, /* like SGP_CACHE, huge pages preferred */
	90	SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
	91	SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
	92	};
	93
	94	extern int shmem_getpage(struct inode *inode, pgoff_t index,
	95	struct page **pagep, enum sgp_type sgp);
	96
d9d90e5e HD	97	static inline struct page *shmem_read_mapping_page(
	98	struct address_space *mapping, pgoff_t index)
	99	{
	100	return shmem_read_mapping_page_gfp(mapping, index,
	101	mapping_gfp_mask(mapping));
	102	}
	103
f3f0e1d2 KS	104	static inline bool shmem_file(struct file *file)
	105	{
	106	if (!IS_ENABLED(CONFIG_SHMEM))
	107	return false;
	108	if (!file \|\| !file->f_mapping)
	109	return false;
	110	return shmem_mapping(file->f_mapping);
	111	}
	112
800d8c63 KS	113	extern bool shmem_charge(struct inode *inode, long pages);
	114	extern void shmem_uncharge(struct inode *inode, long pages);
	115
e496cf3d KS	116	#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
	117	extern bool shmem_huge_enabled(struct vm_area_struct *vma);
	118	#else
	119	static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
	120	{
	121	return false;
	122	}
	123	#endif
	124
4c27fe4c MR	125	#ifdef CONFIG_SHMEM
	126	extern int shmem_mcopy_atomic_pte(struct mm_struct dst_mm, pmd_t dst_pmd,
	127	struct vm_area_struct *dst_vma,
	128	unsigned long dst_addr,
	129	unsigned long src_addr,
	130	struct page **pagep);
8d103963 MR	131	extern int shmem_mfill_zeropage_pte(struct mm_struct *dst_mm,
	132	pmd_t *dst_pmd,
	133	struct vm_area_struct *dst_vma,
	134	unsigned long dst_addr);
4c27fe4c MR	135	#else
	136	#define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \
	137	src_addr, pagep) ({ BUG(); 0; })
8d103963 MR	138	#define shmem_mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, \
8d103963 MR	139	dst_addr) ({ BUG(); 0; })
4c27fe4c MR	140	#endif
4c27fe4c MR	141
1da177e4	142	#endif