[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>
#include <linux/fs_parser.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 */
	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 vm_area_struct *vma, struct inode *inode,
			  pgoff_t index, bool shmem_huge_force);
static inline bool shmem_huge_enabled(struct vm_area_struct *vma,
				      bool shmem_huge_force)
{
	return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff,
			     shmem_huge_force);
}
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_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);

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(struct mm_struct *dst_mm, pmd_t *dst_pmd,
				  struct vm_area_struct *dst_vma,
				  unsigned long dst_addr,
				  unsigned long src_addr,
				  bool zeropage, bool wp_copy,
				  struct page **pagep);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
			       src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
#endif /* CONFIG_SHMEM */
#endif /* CONFIG_USERFAULTFD */

#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>
d7167b14	11	#include <linux/fs_parser.h>
1da177e4 LT	12
	13	/* inode in-kernel data */
	14
1da177e4 LT	15	struct shmem_inode_info {
1da177e4 LT	16	spinlock_t lock;
40e041a2	17	unsigned int seals; /* shmem seals */
1da177e4 LT	18	unsigned long flags;
1da177e4 LT	19	unsigned long alloced; /* data pages alloced to file */
3ed47db3	20	unsigned long swapped; /* subtotal assigned to swap */
d144bf62	21	pgoff_t fallocend; /* highest fallocate endindex */
779750d2	22	struct list_head shrinklist; /* shrinkable hpage inodes */
1da177e4	23	struct list_head swaplist; /* chain of maybes on swap */
779750d2	24	struct shared_policy policy; /* NUMA memory alloc policy */
38f38657	25	struct simple_xattrs xattrs; /* list of xattrs */
af53d3e9	26	atomic_t stop_eviction; /* hold when working on inode */
f7cd16a5	27	struct timespec64 i_crtime; /* file creation time */
e408e695	28	unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */
1da177e4 LT	29	struct inode vfs_inode;
	30	};
	31
cb241339 HD	32	#define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE
	33	#define SHMEM_FL_USER_MODIFIABLE \
	34	(FS_IMMUTABLE_FL \| FS_APPEND_FL \| FS_NODUMP_FL \| FS_NOATIME_FL)
	35	#define SHMEM_FL_INHERITED (FS_NODUMP_FL \| FS_NOATIME_FL)
e408e695	36
1da177e4 LT	37	struct shmem_sb_info {
1da177e4 LT	38	unsigned long max_blocks; /* How many blocks are allowed */
7e496299	39	struct percpu_counter used_blocks; /* How many are allocated */
1da177e4 LT	40	unsigned long max_inodes; /* How many inodes are allowed */
1da177e4 LT	41	unsigned long free_inodes; /* How many are left for allocation */
bf11b9a8	42	raw_spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
5a6e75f8 KS	43	umode_t mode; /* Mount mode for root directory */
5a6e75f8 KS	44	unsigned char huge; /* Whether to try for hugepages */
8751e039 EB	45	kuid_t uid; /* Mount uid for root directory */
8751e039 EB	46	kgid_t gid; /* Mount gid for root directory */
ea3271f7	47	bool full_inums; /* If i_ino should be uint or ino_t */
e809d5f0 CD	48	ino_t next_ino; /* The next per-sb inode number to use */
e809d5f0 CD	49	ino_t __percpu ino_batch; / The next per-cpu inode number to use */
71fe804b	50	struct mempolicy mpol; / default memory policy for mappings */
779750d2 KS	51	spinlock_t shrinklist_lock; /* Protects shrinklist */
	52	struct list_head shrinklist; /* List of shinkable inodes */
	53	unsigned long shrinklist_len; /* Length of shrinklist */
1da177e4 LT	54	};
	55
	56	static inline struct shmem_inode_info SHMEM_I(struct inode inode)
	57	{
	58	return container_of(inode, struct shmem_inode_info, vfs_inode);
	59	}
	60
072441e2 HD	61	/*
	62	* Functions in mm/shmem.c called directly from elsewhere:
	63	*/
d7167b14	64	extern const struct fs_parameter_spec shmem_fs_parameters[];
9096bbe9	65	extern void shmem_init(void);
f3235626	66	extern int shmem_init_fs_context(struct fs_context *fc);
072441e2 HD	67	extern struct file shmem_file_setup(const char name,
072441e2 HD	68	loff_t size, unsigned long flags);
c7277090 EP	69	extern struct file shmem_kernel_file_setup(const char name, loff_t size,
c7277090 EP	70	unsigned long flags);
703321b6 MA	71	extern struct file shmem_file_setup_with_mnt(struct vfsmount mnt,
703321b6 MA	72	const char *name, loff_t size, unsigned long flags);
072441e2	73	extern int shmem_zero_setup(struct vm_area_struct *);
c01d5b30 HD	74	extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
c01d5b30 HD	75	unsigned long len, unsigned long pgoff, unsigned long flags);
d7c9e99a	76	extern int shmem_lock(struct file file, int lock, struct ucounts ucounts);
3a4f8a0b	77	#ifdef CONFIG_SHMEM
30e6a51d HS	78	extern const struct address_space_operations shmem_aops;
	79	static inline bool shmem_mapping(struct address_space *mapping)
	80	{
	81	return mapping->a_ops == &shmem_aops;
	82	}
3a4f8a0b HD	83	#else
	84	static inline bool shmem_mapping(struct address_space *mapping)
	85	{
	86	return false;
	87	}
	88	#endif /* CONFIG_SHMEM */
24513264	89	extern void shmem_unlock_mapping(struct address_space *mapping);
d9d90e5e HD	90	extern struct page shmem_read_mapping_page_gfp(struct address_space mapping,
d9d90e5e HD	91	pgoff_t index, gfp_t gfp_mask);
94c1e62d	92	extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
10a9c496	93	int shmem_unuse(unsigned int type);
2b2af54a	94
7c6c6cc4 ZK	95	extern bool shmem_is_huge(struct vm_area_struct vma, struct inode inode,
	96	pgoff_t index, bool shmem_huge_force);
	97	static inline bool shmem_huge_enabled(struct vm_area_struct *vma,
	98	bool shmem_huge_force)
5e6e5a12	99	{
7c6c6cc4 ZK	100	return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff,
7c6c6cc4 ZK	101	shmem_huge_force);
5e6e5a12	102	}
6a15a370	103	extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
48131e03 VB	104	extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
48131e03 VB	105	pgoff_t start, pgoff_t end);
6a15a370	106
923e2f0e	107	/* Flag allocation requirements to shmem_get_folio */
f3f0e1d2 KS	108	enum sgp_type {
f3f0e1d2 KS	109	SGP_READ, /* don't exceed i_size, don't allocate page */
acdd9f8e	110	SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */
f3f0e1d2	111	SGP_CACHE, /* don't exceed i_size, may allocate page */
f3f0e1d2 KS	112	SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
	113	SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
	114	};
	115
4e1fc793 MWO	116	int shmem_get_folio(struct inode inode, pgoff_t index, struct folio *foliop,
4e1fc793 MWO	117	enum sgp_type sgp);
f3f0e1d2	118
d9d90e5e HD	119	static inline struct page *shmem_read_mapping_page(
	120	struct address_space *mapping, pgoff_t index)
	121	{
	122	return shmem_read_mapping_page_gfp(mapping, index,
	123	mapping_gfp_mask(mapping));
	124	}
	125
f3f0e1d2 KS	126	static inline bool shmem_file(struct file *file)
	127	{
	128	if (!IS_ENABLED(CONFIG_SHMEM))
	129	return false;
	130	if (!file \|\| !file->f_mapping)
	131	return false;
	132	return shmem_mapping(file->f_mapping);
	133	}
	134
d144bf62 HD	135	/*
	136	* If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages
	137	* beyond i_size's notion of EOF, which fallocate has committed to reserving:
	138	* which split_huge_page() must therefore not delete. This use of a single
	139	* "fallocend" per inode errs on the side of not deleting a reservation when
	140	* in doubt: there are plenty of cases when it preserves unreserved pages.
	141	*/
	142	static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof)
	143	{
	144	return max(eof, SHMEM_I(inode)->fallocend);
	145	}
	146
800d8c63 KS	147	extern bool shmem_charge(struct inode *inode, long pages);
	148	extern void shmem_uncharge(struct inode *inode, long pages);
	149
3460f6e5	150	#ifdef CONFIG_USERFAULTFD
4c27fe4c	151	#ifdef CONFIG_SHMEM
3460f6e5	152	extern int shmem_mfill_atomic_pte(struct mm_struct dst_mm, pmd_t dst_pmd,
4c27fe4c MR	153	struct vm_area_struct *dst_vma,
	154	unsigned long dst_addr,
	155	unsigned long src_addr,
8ee79edf	156	bool zeropage, bool wp_copy,
4c27fe4c	157	struct page **pagep);
3460f6e5 AR	158	#else /* !CONFIG_SHMEM */
3460f6e5 AR	159	#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
8ee79edf	160	src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
3460f6e5 AR	161	#endif /* CONFIG_SHMEM */
3460f6e5 AR	162	#endif /* CONFIG_USERFAULTFD */
4c27fe4c	163
1da177e4	164	#endif