167 lines
6.2 KiB
C
167 lines
6.2 KiB
C
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/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __SHMEM_FS_H
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#define __SHMEM_FS_H
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#include <linux/file.h>
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#include <linux/swap.h>
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#include <linux/mempolicy.h>
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#include <linux/pagemap.h>
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#include <linux/percpu_counter.h>
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#include <linux/xattr.h>
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#include <linux/fs_parser.h>
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/* inode in-kernel data */
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struct shmem_inode_info {
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spinlock_t lock;
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unsigned int seals; /* shmem seals */
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unsigned long flags;
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unsigned long alloced; /* data pages alloced to file */
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unsigned long swapped; /* subtotal assigned to swap */
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pgoff_t fallocend; /* highest fallocate endindex */
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struct list_head shrinklist; /* shrinkable hpage inodes */
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struct list_head swaplist; /* chain of maybes on swap */
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struct shared_policy policy; /* NUMA memory alloc policy */
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struct simple_xattrs xattrs; /* list of xattrs */
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atomic_t stop_eviction; /* hold when working on inode */
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struct timespec64 i_crtime; /* file creation time */
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unsigned int fsflags; /* flags for FS_IOC_[SG]ETFLAGS */
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struct inode vfs_inode;
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};
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#define SHMEM_FL_USER_VISIBLE FS_FL_USER_VISIBLE
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#define SHMEM_FL_USER_MODIFIABLE \
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(FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL | FS_NOATIME_FL)
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#define SHMEM_FL_INHERITED (FS_NODUMP_FL | FS_NOATIME_FL)
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struct shmem_sb_info {
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unsigned long max_blocks; /* How many blocks are allowed */
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struct percpu_counter used_blocks; /* How many are allocated */
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unsigned long max_inodes; /* How many inodes are allowed */
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unsigned long free_inodes; /* How many are left for allocation */
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raw_spinlock_t stat_lock; /* Serialize shmem_sb_info changes */
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umode_t mode; /* Mount mode for root directory */
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unsigned char huge; /* Whether to try for hugepages */
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kuid_t uid; /* Mount uid for root directory */
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kgid_t gid; /* Mount gid for root directory */
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bool full_inums; /* If i_ino should be uint or ino_t */
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ino_t next_ino; /* The next per-sb inode number to use */
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ino_t __percpu *ino_batch; /* The next per-cpu inode number to use */
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struct mempolicy *mpol; /* default memory policy for mappings */
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spinlock_t shrinklist_lock; /* Protects shrinklist */
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struct list_head shrinklist; /* List of shinkable inodes */
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unsigned long shrinklist_len; /* Length of shrinklist */
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};
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static inline struct shmem_inode_info *SHMEM_I(struct inode *inode)
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{
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return container_of(inode, struct shmem_inode_info, vfs_inode);
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}
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/*
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* Functions in mm/shmem.c called directly from elsewhere:
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*/
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extern const struct fs_parameter_spec shmem_fs_parameters[];
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extern void shmem_init(void);
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extern int shmem_init_fs_context(struct fs_context *fc);
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extern struct file *shmem_file_setup(const char *name,
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loff_t size, unsigned long flags);
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extern struct file *shmem_kernel_file_setup(const char *name, loff_t size,
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unsigned long flags);
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extern struct file *shmem_file_setup_with_mnt(struct vfsmount *mnt,
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const char *name, loff_t size, unsigned long flags);
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extern int shmem_zero_setup(struct vm_area_struct *);
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extern unsigned long shmem_get_unmapped_area(struct file *, unsigned long addr,
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unsigned long len, unsigned long pgoff, unsigned long flags);
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extern int shmem_lock(struct file *file, int lock, struct ucounts *ucounts);
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#ifdef CONFIG_SHMEM
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extern const struct address_space_operations shmem_aops;
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static inline bool shmem_mapping(struct address_space *mapping)
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{
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return mapping->a_ops == &shmem_aops;
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}
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#else
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static inline bool shmem_mapping(struct address_space *mapping)
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{
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return false;
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}
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#endif /* CONFIG_SHMEM */
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extern void shmem_unlock_mapping(struct address_space *mapping);
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extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
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pgoff_t index, gfp_t gfp_mask);
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extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
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int shmem_unuse(unsigned int type);
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extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
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struct mm_struct *mm, unsigned long vm_flags);
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extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
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extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
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pgoff_t start, pgoff_t end);
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/* Flag allocation requirements to shmem_get_folio */
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enum sgp_type {
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SGP_READ, /* don't exceed i_size, don't allocate page */
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SGP_NOALLOC, /* similar, but fail on hole or use fallocated page */
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SGP_CACHE, /* don't exceed i_size, may allocate page */
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SGP_WRITE, /* may exceed i_size, may allocate !Uptodate page */
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SGP_FALLOC, /* like SGP_WRITE, but make existing page Uptodate */
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};
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int shmem_get_folio(struct inode *inode, pgoff_t index, struct folio **foliop,
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enum sgp_type sgp);
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struct folio *shmem_read_folio_gfp(struct address_space *mapping,
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pgoff_t index, gfp_t gfp);
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static inline struct folio *shmem_read_folio(struct address_space *mapping,
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pgoff_t index)
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{
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return shmem_read_folio_gfp(mapping, index, mapping_gfp_mask(mapping));
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}
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static inline struct page *shmem_read_mapping_page(
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struct address_space *mapping, pgoff_t index)
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{
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return shmem_read_mapping_page_gfp(mapping, index,
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mapping_gfp_mask(mapping));
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}
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static inline bool shmem_file(struct file *file)
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{
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if (!IS_ENABLED(CONFIG_SHMEM))
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return false;
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if (!file || !file->f_mapping)
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return false;
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return shmem_mapping(file->f_mapping);
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}
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/*
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* If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages
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* beyond i_size's notion of EOF, which fallocate has committed to reserving:
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* which split_huge_page() must therefore not delete. This use of a single
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* "fallocend" per inode errs on the side of not deleting a reservation when
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* in doubt: there are plenty of cases when it preserves unreserved pages.
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*/
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static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof)
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{
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return max(eof, SHMEM_I(inode)->fallocend);
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}
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extern bool shmem_charge(struct inode *inode, long pages);
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extern void shmem_uncharge(struct inode *inode, long pages);
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#ifdef CONFIG_USERFAULTFD
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#ifdef CONFIG_SHMEM
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extern int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
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struct vm_area_struct *dst_vma,
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unsigned long dst_addr,
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unsigned long src_addr,
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bool zeropage, bool wp_copy,
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struct page **pagep);
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#else /* !CONFIG_SHMEM */
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#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
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src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
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#endif /* CONFIG_SHMEM */
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#endif /* CONFIG_USERFAULTFD */
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#endif
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