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gerrit-public.fairphone.software / kernel / msm-5.4 / f0bb5aaf2c51267c49ed5e2c6103df22acfe30f5 / . / include / linux / fs.h
blob: 0e177d395efbf5940639aab175a6ba87a53fe1dc [file] [log] [blame]
#ifndef _LINUX_FS_H
#define _LINUX_FS_H
#include <linux/linkage.h>
#include <linux/wait.h>
#include <linux/kdev_t.h>
#include <linux/dcache.h>
#include <linux/path.h>
#include <linux/stat.h>
#include <linux/cache.h>
#include <linux/list.h>
#include <linux/list_lru.h>
#include <linux/llist.h>
#include <linux/radix-tree.h>
#include <linux/rbtree.h>
#include <linux/init.h>
#include <linux/pid.h>
#include <linux/bug.h>
#include <linux/mutex.h>
#include <linux/rwsem.h>
#include <linux/capability.h>
#include <linux/semaphore.h>
#include <linux/fiemap.h>
#include <linux/rculist_bl.h>
#include <linux/atomic.h>
#include <linux/shrinker.h>
#include <linux/migrate_mode.h>
#include <linux/uidgid.h>
#include <linux/lockdep.h>
#include <linux/percpu-rwsem.h>
#include <linux/blk_types.h>
#include <linux/workqueue.h>
#include <linux/percpu-rwsem.h>
#include <linux/delayed_call.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
struct backing_dev_info;
struct bdi_writeback;
struct export_operations;
struct hd_geometry;
struct iovec;
struct kiocb;
struct kobject;
struct pipe_inode_info;
struct poll_table_struct;
struct kstatfs;
struct vm_area_struct;
struct vfsmount;
struct cred;
struct swap_info_struct;
struct seq_file;
struct workqueue_struct;
struct iov_iter;
struct fscrypt_info;
struct fscrypt_operations;
extern void __init inode_init(void);
extern void __init inode_init_early(void);
extern void __init files_init(void);
extern void __init files_maxfiles_init(void);
extern struct files_stat_struct files_stat;
extern unsigned long get_max_files(void);
extern unsigned int sysctl_nr_open;
extern struct inodes_stat_t inodes_stat;
extern int leases_enable, lease_break_time;
extern int sysctl_protected_symlinks;
extern int sysctl_protected_hardlinks;
struct buffer_head;
typedef int (get_block_t)(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create);
typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
ssize_t bytes, void *private);
#define MAY_EXEC 0x00000001
#define MAY_WRITE 0x00000002
#define MAY_READ 0x00000004
#define MAY_APPEND 0x00000008
#define MAY_ACCESS 0x00000010
#define MAY_OPEN 0x00000020
#define MAY_CHDIR 0x00000040
/* called from RCU mode, don't block */
#define MAY_NOT_BLOCK 0x00000080
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond
* to O_WRONLY and O_RDWR via the strange trick in __dentry_open()
*/
/* file is open for reading */
#define FMODE_READ ((__force fmode_t)0x1)
/* file is open for writing */
#define FMODE_WRITE ((__force fmode_t)0x2)
/* file is seekable */
#define FMODE_LSEEK ((__force fmode_t)0x4)
/* file can be accessed using pread */
#define FMODE_PREAD ((__force fmode_t)0x8)
/* file can be accessed using pwrite */
#define FMODE_PWRITE ((__force fmode_t)0x10)
/* File is opened for execution with sys_execve / sys_uselib */
#define FMODE_EXEC ((__force fmode_t)0x20)
/* File is opened with O_NDELAY (only set for block devices) */
#define FMODE_NDELAY ((__force fmode_t)0x40)
/* File is opened with O_EXCL (only set for block devices) */
#define FMODE_EXCL ((__force fmode_t)0x80)
/* File is opened using open(.., 3, ..) and is writeable only for ioctls
(specialy hack for floppy.c) */
#define FMODE_WRITE_IOCTL ((__force fmode_t)0x100)
/* 32bit hashes as llseek() offset (for directories) */
#define FMODE_32BITHASH ((__force fmode_t)0x200)
/* 64bit hashes as llseek() offset (for directories) */
#define FMODE_64BITHASH ((__force fmode_t)0x400)
/*
* Don't update ctime and mtime.
*
* Currently a special hack for the XFS open_by_handle ioctl, but we'll
* hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.
*/
#define FMODE_NOCMTIME ((__force fmode_t)0x800)
/* Expect random access pattern */
#define FMODE_RANDOM ((__force fmode_t)0x1000)
/* File is huge (eg. /dev/kmem): treat loff_t as unsigned */
#define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000)
/* File is opened with O_PATH; almost nothing can be done with it */
#define FMODE_PATH ((__force fmode_t)0x4000)
/* File needs atomic accesses to f_pos */
#define FMODE_ATOMIC_POS ((__force fmode_t)0x8000)
/* Write access to underlying fs */
#define FMODE_WRITER ((__force fmode_t)0x10000)
/* Has read method(s) */
#define FMODE_CAN_READ ((__force fmode_t)0x20000)
/* Has write method(s) */
#define FMODE_CAN_WRITE ((__force fmode_t)0x40000)
/* File was opened by fanotify and shouldn't generate fanotify events */
#define FMODE_NONOTIFY ((__force fmode_t)0x4000000)
/*
* Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
* that indicates that they should check the contents of the iovec are
* valid, but not check the memory that the iovec elements
* points too.
*/
#define CHECK_IOVEC_ONLY -1
/*
* The below are the various read and write flags that we support. Some of
* them include behavioral modifiers that send information down to the
* block layer and IO scheduler. They should be used along with a req_op.
* Terminology:
*
* The block layer uses device plugging to defer IO a little bit, in
* the hope that we will see more IO very shortly. This increases
* coalescing of adjacent IO and thus reduces the number of IOs we
* have to send to the device. It also allows for better queuing,
* if the IO isn't mergeable. If the caller is going to be waiting
* for the IO, then he must ensure that the device is unplugged so
* that the IO is dispatched to the driver.
*
* All IO is handled async in Linux. This is fine for background
* writes, but for reads or writes that someone waits for completion
* on, we want to notify the block layer and IO scheduler so that they
* know about it. That allows them to make better scheduling
* decisions. So when the below references 'sync' and 'async', it
* is referencing this priority hint.
*
* With that in mind, the available types are:
*
* READ A normal read operation. Device will be plugged.
* READ_SYNC A synchronous read. Device is not plugged, caller can
* immediately wait on this read without caring about
* unplugging.
* WRITE A normal async write. Device will be plugged.
* WRITE_SYNC Synchronous write. Identical to WRITE, but passes down
* the hint that someone will be waiting on this IO
* shortly. The write equivalent of READ_SYNC.
* WRITE_ODIRECT Special case write for O_DIRECT only.
* WRITE_FLUSH Like WRITE_SYNC but with preceding cache flush.
* WRITE_FUA Like WRITE_SYNC but data is guaranteed to be on
* non-volatile media on completion.
* WRITE_FLUSH_FUA Combination of WRITE_FLUSH and FUA. The IO is preceded
* by a cache flush and data is guaranteed to be on
* non-volatile media on completion.
*
*/
#define RW_MASK REQ_OP_WRITE
#define READ REQ_OP_READ
#define WRITE REQ_OP_WRITE
#define READ_SYNC REQ_SYNC
#define WRITE_SYNC (REQ_SYNC | REQ_NOIDLE)
#define WRITE_ODIRECT REQ_SYNC
#define WRITE_FLUSH (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH)
#define WRITE_FUA (REQ_SYNC | REQ_NOIDLE | REQ_FUA)
#define WRITE_FLUSH_FUA (REQ_SYNC | REQ_NOIDLE | REQ_PREFLUSH | REQ_FUA)
/*
* Attribute flags. These should be or-ed together to figure out what
* has been changed!
*/
#define ATTR_MODE (1 << 0)
#define ATTR_UID (1 << 1)
#define ATTR_GID (1 << 2)
#define ATTR_SIZE (1 << 3)
#define ATTR_ATIME (1 << 4)
#define ATTR_MTIME (1 << 5)
#define ATTR_CTIME (1 << 6)
#define ATTR_ATIME_SET (1 << 7)
#define ATTR_MTIME_SET (1 << 8)
#define ATTR_FORCE (1 << 9) /* Not a change, but a change it */
#define ATTR_ATTR_FLAG (1 << 10)
#define ATTR_KILL_SUID (1 << 11)
#define ATTR_KILL_SGID (1 << 12)
#define ATTR_FILE (1 << 13)
#define ATTR_KILL_PRIV (1 << 14)
#define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */
#define ATTR_TIMES_SET (1 << 16)
#define ATTR_TOUCH (1 << 17)
/*
* Whiteout is represented by a char device. The following constants define the
* mode and device number to use.
*/
#define WHITEOUT_MODE 0
#define WHITEOUT_DEV 0
/*
* This is the Inode Attributes structure, used for notify_change(). It
* uses the above definitions as flags, to know which values have changed.
* Also, in this manner, a Filesystem can look at only the values it cares
* about. Basically, these are the attributes that the VFS layer can
* request to change from the FS layer.
*
* Derek Atkins <warlord@MIT.EDU> 94-10-20
*/
struct iattr {
unsigned int ia_valid;
umode_t ia_mode;
kuid_t ia_uid;
kgid_t ia_gid;
loff_t ia_size;
struct timespec ia_atime;
struct timespec ia_mtime;
struct timespec ia_ctime;
/*
* Not an attribute, but an auxiliary info for filesystems wanting to
* implement an ftruncate() like method. NOTE: filesystem should
* check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).
*/
struct file *ia_file;
};
/*
* Includes for diskquotas.
*/
#include <linux/quota.h>
/*
* Maximum number of layers of fs stack. Needs to be limited to
* prevent kernel stack overflow
*/
#define FILESYSTEM_MAX_STACK_DEPTH 2
/**
* enum positive_aop_returns - aop return codes with specific semantics
*
* @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has
* completed, that the page is still locked, and
* should be considered active. The VM uses this hint
* to return the page to the active list -- it won't
* be a candidate for writeback again in the near
* future. Other callers must be careful to unlock
* the page if they get this return. Returned by
* writepage();
*
* @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has
* unlocked it and the page might have been truncated.
* The caller should back up to acquiring a new page and
* trying again. The aop will be taking reasonable
* precautions not to livelock. If the caller held a page
* reference, it should drop it before retrying. Returned
* by readpage().
*
* address_space_operation functions return these large constants to indicate
* special semantics to the caller. These are much larger than the bytes in a
* page to allow for functions that return the number of bytes operated on in a
* given page.
*/
enum positive_aop_returns {
AOP_WRITEPAGE_ACTIVATE = 0x80000,
AOP_TRUNCATED_PAGE = 0x80001,
};
#define AOP_FLAG_UNINTERRUPTIBLE 0x0001 /* will not do a short write */
#define AOP_FLAG_CONT_EXPAND 0x0002 /* called from cont_expand */
#define AOP_FLAG_NOFS 0x0004 /* used by filesystem to direct
* helper code (eg buffer layer)
* to clear GFP_FS from alloc */
/*
* oh the beauties of C type declarations.
*/
struct page;
struct address_space;
struct writeback_control;
#define IOCB_EVENTFD (1 << 0)
#define IOCB_APPEND (1 << 1)
#define IOCB_DIRECT (1 << 2)
#define IOCB_HIPRI (1 << 3)
#define IOCB_DSYNC (1 << 4)
#define IOCB_SYNC (1 << 5)
#define IOCB_WRITE (1 << 6)
struct kiocb {
struct file *ki_filp;
loff_t ki_pos;
void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);
void *private;
int ki_flags;
};
static inline bool is_sync_kiocb(struct kiocb *kiocb)
{
return kiocb->ki_complete == NULL;
}
static inline int iocb_flags(struct file *file);
static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
{
*kiocb = (struct kiocb) {
.ki_filp = filp,
.ki_flags = iocb_flags(filp),
};
}
/*
* "descriptor" for what we're up to with a read.
* This allows us to use the same read code yet
* have multiple different users of the data that
* we read from a file.
*
* The simplest case just copies the data to user
* mode.
*/
typedef struct {
size_t written;
size_t count;
union {
char __user *buf;
void *data;
} arg;
int error;
} read_descriptor_t;
typedef int (*read_actor_t)(read_descriptor_t *, struct page *,
unsigned long, unsigned long);
struct address_space_operations {
int (*writepage)(struct page *page, struct writeback_control *wbc);
int (*readpage)(struct file *, struct page *);
/* Write back some dirty pages from this mapping. */
int (*writepages)(struct address_space *, struct writeback_control *);
/* Set a page dirty. Return true if this dirtied it */
int (*set_page_dirty)(struct page *page);
int (*readpages)(struct file *filp, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages);
int (*write_begin)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
int (*write_end)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
/* Unfortunately this kludge is needed for FIBMAP. Don't use it */
sector_t (*bmap)(struct address_space *, sector_t);
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, gfp_t);
void (*freepage)(struct page *);
ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
/*
* migrate the contents of a page to the specified target. If
* migrate_mode is MIGRATE_ASYNC, it must not block.
*/
int (*migratepage) (struct address_space *,
struct page *, struct page *, enum migrate_mode);
bool (*isolate_page)(struct page *, isolate_mode_t);
void (*putback_page)(struct page *);
int (*launder_page) (struct page *);
int (*is_partially_uptodate) (struct page *, unsigned long,
unsigned long);
void (*is_dirty_writeback) (struct page *, bool *, bool *);
int (*error_remove_page)(struct address_space *, struct page *);
/* swapfile support */
int (*swap_activate)(struct swap_info_struct *sis, struct file *file,
sector_t *span);
void (*swap_deactivate)(struct file *file);
};
extern const struct address_space_operations empty_aops;
/*
* pagecache_write_begin/pagecache_write_end must be used by general code
* to write into the pagecache.
*/
int pagecache_write_begin(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
int pagecache_write_end(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
struct address_space {
struct inode *host; /* owner: inode, block_device */
struct radix_tree_root page_tree; /* radix tree of all pages */
spinlock_t tree_lock; /* and lock protecting it */
atomic_t i_mmap_writable;/* count VM_SHARED mappings */
struct rb_root i_mmap; /* tree of private and shared mappings */
struct rw_semaphore i_mmap_rwsem; /* protect tree, count, list */
/* Protected by tree_lock together with the radix tree */
unsigned long nrpages; /* number of total pages */
/* number of shadow or DAX exceptional entries */
unsigned long nrexceptional;
pgoff_t writeback_index;/* writeback starts here */
const struct address_space_operations *a_ops; /* methods */
unsigned long flags; /* error bits */
spinlock_t private_lock; /* for use by the address_space */
gfp_t gfp_mask; /* implicit gfp mask for allocations */
struct list_head private_list; /* ditto */
void *private_data; /* ditto */
} __attribute__((aligned(sizeof(long))));
/*
* On most architectures that alignment is already the case; but
* must be enforced here for CRIS, to let the least significant bit
* of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.
*/
struct request_queue;
struct block_device {
dev_t bd_dev; /* not a kdev_t - it's a search key */
int bd_openers;
struct inode * bd_inode; /* will die */
struct super_block * bd_super;
struct mutex bd_mutex; /* open/close mutex */
void * bd_claiming;
void * bd_holder;
int bd_holders;
bool bd_write_holder;
#ifdef CONFIG_SYSFS
struct list_head bd_holder_disks;
#endif
struct block_device * bd_contains;
unsigned bd_block_size;
struct hd_struct * bd_part;
/* number of times partitions within this device have been opened. */
unsigned bd_part_count;
int bd_invalidated;
struct gendisk * bd_disk;
struct request_queue * bd_queue;
struct list_head bd_list;
/*
* Private data. You must have bd_claim'ed the block_device
* to use this. NOTE: bd_claim allows an owner to claim
* the same device multiple times, the owner must take special
* care to not mess up bd_private for that case.
*/
unsigned long bd_private;
/* The counter of freeze processes */
int bd_fsfreeze_count;
/* Mutex for freeze */
struct mutex bd_fsfreeze_mutex;
};
/*
* Radix-tree tags, for tagging dirty and writeback pages within the pagecache
* radix trees
*/
#define PAGECACHE_TAG_DIRTY 0
#define PAGECACHE_TAG_WRITEBACK 1
#define PAGECACHE_TAG_TOWRITE 2
int mapping_tagged(struct address_space *mapping, int tag);
static inline void i_mmap_lock_write(struct address_space *mapping)
{
down_write(&mapping->i_mmap_rwsem);
}
static inline void i_mmap_unlock_write(struct address_space *mapping)
{
up_write(&mapping->i_mmap_rwsem);
}
static inline void i_mmap_lock_read(struct address_space *mapping)
{
down_read(&mapping->i_mmap_rwsem);
}
static inline void i_mmap_unlock_read(struct address_space *mapping)
{
up_read(&mapping->i_mmap_rwsem);
}
/*
* Might pages of this file be mapped into userspace?
*/
static inline int mapping_mapped(struct address_space *mapping)
{
return !RB_EMPTY_ROOT(&mapping->i_mmap);
}
/*
* Might pages of this file have been modified in userspace?
* Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff
* marks vma as VM_SHARED if it is shared, and the file was opened for
* writing i.e. vma may be mprotected writable even if now readonly.
*
* If i_mmap_writable is negative, no new writable mappings are allowed. You
* can only deny writable mappings, if none exists right now.
*/
static inline int mapping_writably_mapped(struct address_space *mapping)
{
return atomic_read(&mapping->i_mmap_writable) > 0;
}
static inline int mapping_map_writable(struct address_space *mapping)
{
return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?
0 : -EPERM;
}
static inline void mapping_unmap_writable(struct address_space *mapping)
{
atomic_dec(&mapping->i_mmap_writable);
}
static inline int mapping_deny_writable(struct address_space *mapping)
{
return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?
0 : -EBUSY;
}
static inline void mapping_allow_writable(struct address_space *mapping)
{
atomic_inc(&mapping->i_mmap_writable);
}
/*
* Use sequence counter to get consistent i_size on 32-bit processors.
*/
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
#include <linux/seqlock.h>
#define __NEED_I_SIZE_ORDERED
#define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount)
#else
#define i_size_ordered_init(inode) do { } while (0)
#endif
struct posix_acl;
#define ACL_NOT_CACHED ((void *)(-1))
#define ACL_DONT_CACHE ((void *)(-3))
static inline struct posix_acl *
uncached_acl_sentinel(struct task_struct *task)
{
return (void *)task + 1;
}
static inline bool
is_uncached_acl(struct posix_acl *acl)
{
return (long)acl & 1;
}
#define IOP_FASTPERM 0x0001
#define IOP_LOOKUP 0x0002
#define IOP_NOFOLLOW 0x0004
#define IOP_XATTR 0x0008
/*
* Keep mostly read-only and often accessed (especially for
* the RCU path lookup and 'stat' data) fields at the beginning
* of the 'struct inode'
*/
struct inode {
umode_t i_mode;
unsigned short i_opflags;
kuid_t i_uid;
kgid_t i_gid;
unsigned int i_flags;
#ifdef CONFIG_FS_POSIX_ACL
struct posix_acl *i_acl;
struct posix_acl *i_default_acl;
#endif
const struct inode_operations *i_op;
struct super_block *i_sb;
struct address_space *i_mapping;
#ifdef CONFIG_SECURITY
void *i_security;
#endif
/* Stat data, not accessed from path walking */
unsigned long i_ino;
/*
* Filesystems may only read i_nlink directly. They shall use the
* following functions for modification:
*
* (set|clear|inc|drop)_nlink
* inode_(inc|dec)_link_count
*/
union {
const unsigned int i_nlink;
unsigned int __i_nlink;
};
dev_t i_rdev;
loff_t i_size;
struct timespec i_atime;
struct timespec i_mtime;
struct timespec i_ctime;
spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */
unsigned short i_bytes;
unsigned int i_blkbits;
blkcnt_t i_blocks;
#ifdef __NEED_I_SIZE_ORDERED
seqcount_t i_size_seqcount;
#endif
/* Misc */
unsigned long i_state;
struct rw_semaphore i_rwsem;
unsigned long dirtied_when; /* jiffies of first dirtying */
unsigned long dirtied_time_when;
struct hlist_node i_hash;
struct list_head i_io_list; /* backing dev IO list */
#ifdef CONFIG_CGROUP_WRITEBACK
struct bdi_writeback *i_wb; /* the associated cgroup wb */
/* foreign inode detection, see wbc_detach_inode() */
int i_wb_frn_winner;
u16 i_wb_frn_avg_time;
u16 i_wb_frn_history;
#endif
struct list_head i_lru; /* inode LRU list */
struct list_head i_sb_list;
struct list_head i_wb_list; /* backing dev writeback list */
union {
struct hlist_head i_dentry;
struct rcu_head i_rcu;
};
u64 i_version;
atomic_t i_count;
atomic_t i_dio_count;
atomic_t i_writecount;
#ifdef CONFIG_IMA
atomic_t i_readcount; /* struct files open RO */
#endif
const struct file_operations *i_fop; /* former ->i_op->default_file_ops */
struct file_lock_context *i_flctx;
struct address_space i_data;
struct list_head i_devices;
union {
struct pipe_inode_info *i_pipe;
struct block_device *i_bdev;
struct cdev *i_cdev;
char *i_link;
unsigned i_dir_seq;
};
__u32 i_generation;
#ifdef CONFIG_FSNOTIFY
__u32 i_fsnotify_mask; /* all events this inode cares about */
struct hlist_head i_fsnotify_marks;
#endif
#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
struct fscrypt_info *i_crypt_info;
#endif
void *i_private; /* fs or device private pointer */
};
static inline int inode_unhashed(struct inode *inode)
{
return hlist_unhashed(&inode->i_hash);
}
/*
* inode->i_mutex nesting subclasses for the lock validator:
*
* 0: the object of the current VFS operation
* 1: parent
* 2: child/target
* 3: xattr
* 4: second non-directory
* 5: second parent (when locking independent directories in rename)
*
* I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two
* non-directories at once.
*
* The locking order between these classes is
* parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory
*/
enum inode_i_mutex_lock_class
{
I_MUTEX_NORMAL,
I_MUTEX_PARENT,
I_MUTEX_CHILD,
I_MUTEX_XATTR,
I_MUTEX_NONDIR2,
I_MUTEX_PARENT2,
};
static inline void inode_lock(struct inode *inode)
{
down_write(&inode->i_rwsem);
}
static inline void inode_unlock(struct inode *inode)
{
up_write(&inode->i_rwsem);
}
static inline void inode_lock_shared(struct inode *inode)
{
down_read(&inode->i_rwsem);
}
static inline void inode_unlock_shared(struct inode *inode)
{
up_read(&inode->i_rwsem);
}
static inline int inode_trylock(struct inode *inode)
{
return down_write_trylock(&inode->i_rwsem);
}
static inline int inode_trylock_shared(struct inode *inode)
{
return down_read_trylock(&inode->i_rwsem);
}
static inline int inode_is_locked(struct inode *inode)
{
return rwsem_is_locked(&inode->i_rwsem);
}
static inline void inode_lock_nested(struct inode *inode, unsigned subclass)
{
down_write_nested(&inode->i_rwsem, subclass);
}
void lock_two_nondirectories(struct inode *, struct inode*);
void unlock_two_nondirectories(struct inode *, struct inode*);
/*
* NOTE: in a 32bit arch with a preemptable kernel and
* an UP compile the i_size_read/write must be atomic
* with respect to the local cpu (unlike with preempt disabled),
* but they don't need to be atomic with respect to other cpus like in
* true SMP (so they need either to either locally disable irq around
* the read or for example on x86 they can be still implemented as a
* cmpxchg8b without the need of the lock prefix). For SMP compiles
* and 64bit archs it makes no difference if preempt is enabled or not.
*/
static inline loff_t i_size_read(const struct inode *inode)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
loff_t i_size;
unsigned int seq;
do {
seq = read_seqcount_begin(&inode->i_size_seqcount);
i_size = inode->i_size;
} while (read_seqcount_retry(&inode->i_size_seqcount, seq));
return i_size;
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
loff_t i_size;
preempt_disable();
i_size = inode->i_size;
preempt_enable();
return i_size;
#else
return inode->i_size;
#endif
}
/*
* NOTE: unlike i_size_read(), i_size_write() does need locking around it
* (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount
* can be lost, resulting in subsequent i_size_read() calls spinning forever.
*/
static inline void i_size_write(struct inode *inode, loff_t i_size)
{
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
preempt_disable();
write_seqcount_begin(&inode->i_size_seqcount);
inode->i_size = i_size;
write_seqcount_end(&inode->i_size_seqcount);
preempt_enable();
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
preempt_disable();
inode->i_size = i_size;
preempt_enable();
#else
inode->i_size = i_size;
#endif
}
static inline unsigned iminor(const struct inode *inode)
{
return MINOR(inode->i_rdev);
}
static inline unsigned imajor(const struct inode *inode)
{
return MAJOR(inode->i_rdev);
}
extern struct block_device *I_BDEV(struct inode *inode);
struct fown_struct {
rwlock_t lock; /* protects pid, uid, euid fields */
struct pid *pid; /* pid or -pgrp where SIGIO should be sent */
enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */
kuid_t uid, euid; /* uid/euid of process setting the owner */
int signum; /* posix.1b rt signal to be delivered on IO */
};
/*
* Track a single file's readahead state
*/
struct file_ra_state {
pgoff_t start; /* where readahead started */
unsigned int size; /* # of readahead pages */
unsigned int async_size; /* do asynchronous readahead when
there are only # of pages ahead */
unsigned int ra_pages; /* Maximum readahead window */
unsigned int mmap_miss; /* Cache miss stat for mmap accesses */
loff_t prev_pos; /* Cache last read() position */
};
/*
* Check if @index falls in the readahead windows.
*/
static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
{
return (index >= ra->start &&
index < ra->start + ra->size);
}
struct file {
union {
struct llist_node fu_llist;
struct rcu_head fu_rcuhead;
} f_u;
struct path f_path;
struct inode *f_inode; /* cached value */
const struct file_operations *f_op;
/*
* Protects f_ep_links, f_flags.
* Must not be taken from IRQ context.
*/
spinlock_t f_lock;
atomic_long_t f_count;
unsigned int f_flags;
fmode_t f_mode;
struct mutex f_pos_lock;
loff_t f_pos;
struct fown_struct f_owner;
const struct cred *f_cred;
struct file_ra_state f_ra;
u64 f_version;
#ifdef CONFIG_SECURITY
void *f_security;
#endif
/* needed for tty driver, and maybe others */
void *private_data;
#ifdef CONFIG_EPOLL
/* Used by fs/eventpoll.c to link all the hooks to this file */
struct list_head f_ep_links;
struct list_head f_tfile_llink;
#endif /* #ifdef CONFIG_EPOLL */
struct address_space *f_mapping;
} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
struct file_handle {
__u32 handle_bytes;
int handle_type;
/* file identifier */
unsigned char f_handle[0];
};
static inline struct file *get_file(struct file *f)
{
atomic_long_inc(&f->f_count);
return f;
}
#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
#define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1)
#define file_count(x) atomic_long_read(&(x)->f_count)
#define MAX_NON_LFS ((1UL<<31) - 1)
/* Page cache limit. The filesystems should put that into their s_maxbytes
limits, otherwise bad things can happen in VM. */
#if BITS_PER_LONG==32
#define MAX_LFS_FILESIZE (((loff_t)PAGE_SIZE << (BITS_PER_LONG-1))-1)
#elif BITS_PER_LONG==64
#define MAX_LFS_FILESIZE ((loff_t)0x7fffffffffffffffLL)
#endif
#define FL_POSIX 1
#define FL_FLOCK 2
#define FL_DELEG 4 /* NFSv4 delegation */
#define FL_ACCESS 8 /* not trying to lock, just looking */
#define FL_EXISTS 16 /* when unlocking, test for existence */
#define FL_LEASE 32 /* lease held on this file */
#define FL_CLOSE 64 /* unlock on close */
#define FL_SLEEP 128 /* A blocking lock */
#define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */
#define FL_UNLOCK_PENDING 512 /* Lease is being broken */
#define FL_OFDLCK 1024 /* lock is "owned" by struct file */
#define FL_LAYOUT 2048 /* outstanding pNFS layout */
/*
* Special return value from posix_lock_file() and vfs_lock_file() for
* asynchronous locking.
*/
#define FILE_LOCK_DEFERRED 1
/* legacy typedef, should eventually be removed */
typedef void *fl_owner_t;
struct file_lock;
struct file_lock_operations {
void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
void (*fl_release_private)(struct file_lock *);
};
struct lock_manager_operations {
int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
unsigned long (*lm_owner_key)(struct file_lock *);
fl_owner_t (*lm_get_owner)(fl_owner_t);
void (*lm_put_owner)(fl_owner_t);
void (*lm_notify)(struct file_lock *); /* unblock callback */
int (*lm_grant)(struct file_lock *, int);
bool (*lm_break)(struct file_lock *);
int (*lm_change)(struct file_lock *, int, struct list_head *);
void (*lm_setup)(struct file_lock *, void **);
};
struct lock_manager {
struct list_head list;
/*
* NFSv4 and up also want opens blocked during the grace period;
* NLM doesn't care:
*/
bool block_opens;
};
struct net;
void locks_start_grace(struct net *, struct lock_manager *);
void locks_end_grace(struct lock_manager *);
int locks_in_grace(struct net *);
int opens_in_grace(struct net *);
/* that will die - we need it for nfs_lock_info */
#include <linux/nfs_fs_i.h>
/*
* struct file_lock represents a generic "file lock". It's used to represent
* POSIX byte range locks, BSD (flock) locks, and leases. It's important to
* note that the same struct is used to represent both a request for a lock and
* the lock itself, but the same object is never used for both.
*
* FIXME: should we create a separate "struct lock_request" to help distinguish
* these two uses?
*
* The varous i_flctx lists are ordered by:
*
* 1) lock owner
* 2) lock range start
* 3) lock range end
*
* Obviously, the last two criteria only matter for POSIX locks.
*/
struct file_lock {
struct file_lock *fl_next; /* singly linked list for this inode */
struct list_head fl_list; /* link into file_lock_context */
struct hlist_node fl_link; /* node in global lists */
struct list_head fl_block; /* circular list of blocked processes */
fl_owner_t fl_owner;
unsigned int fl_flags;
unsigned char fl_type;
unsigned int fl_pid;
int fl_link_cpu; /* what cpu's list is this on? */
struct pid *fl_nspid;
wait_queue_head_t fl_wait;
struct file *fl_file;
loff_t fl_start;
loff_t fl_end;
struct fasync_struct * fl_fasync; /* for lease break notifications */
/* for lease breaks: */
unsigned long fl_break_time;
unsigned long fl_downgrade_time;
const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */
const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */
union {
struct nfs_lock_info nfs_fl;
struct nfs4_lock_info nfs4_fl;
struct {
struct list_head link; /* link in AFS vnode's pending_locks list */
int state; /* state of grant or error if -ve */
} afs;
} fl_u;
};
struct file_lock_context {
spinlock_t flc_lock;
struct list_head flc_flock;
struct list_head flc_posix;
struct list_head flc_lease;
};
/* The following constant reflects the upper bound of the file/locking space */
#ifndef OFFSET_MAX
#define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1)))
#define OFFSET_MAX INT_LIMIT(loff_t)
#define OFFT_OFFSET_MAX INT_LIMIT(off_t)
#endif
#include <linux/fcntl.h>
extern void send_sigio(struct fown_struct *fown, int fd, int band);
/*
* Return the inode to use for locking
*
* For overlayfs this should be the overlay inode, not the real inode returned
* by file_inode(). For any other fs file_inode(filp) and locks_inode(filp) are
* equal.
*/
static inline struct inode *locks_inode(const struct file *f)
{
return f->f_path.dentry->d_inode;
}
#ifdef CONFIG_FILE_LOCKING
extern int fcntl_getlk(struct file *, unsigned int, struct flock __user *);
extern int fcntl_setlk(unsigned int, struct file *, unsigned int,
struct flock __user *);
#if BITS_PER_LONG == 32
extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 __user *);
extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,
struct flock64 __user *);
#endif
extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg);
extern int fcntl_getlease(struct file *filp);
/* fs/locks.c */
void locks_free_lock_context(struct inode *inode);
void locks_free_lock(struct file_lock *fl);
extern void locks_init_lock(struct file_lock *);
extern struct file_lock * locks_alloc_lock(void);
extern void locks_copy_lock(struct file_lock *, struct file_lock *);
extern void locks_copy_conflock(struct file_lock *, struct file_lock *);
extern void locks_remove_posix(struct file *, fl_owner_t);
extern void locks_remove_file(struct file *);
extern void locks_release_private(struct file_lock *);
extern void posix_test_lock(struct file *, struct file_lock *);
extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);
extern int posix_unblock_lock(struct file_lock *);
extern int vfs_test_lock(struct file *, struct file_lock *);
extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *);
extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl);
extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
extern void lease_get_mtime(struct inode *, struct timespec *time);
extern int generic_setlease(struct file *, long, struct file_lock **, void **priv);
extern int vfs_setlease(struct file *, long, struct file_lock **, void **);
extern int lease_modify(struct file_lock *, int, struct list_head *);
struct files_struct;
extern void show_fd_locks(struct seq_file *f,
struct file *filp, struct files_struct *files);
#else /* !CONFIG_FILE_LOCKING */
static inline int fcntl_getlk(struct file *file, unsigned int cmd,
struct flock __user *user)
{
return -EINVAL;
}
static inline int fcntl_setlk(unsigned int fd, struct file *file,
unsigned int cmd, struct flock __user *user)
{
return -EACCES;
}
#if BITS_PER_LONG == 32
static inline int fcntl_getlk64(struct file *file, unsigned int cmd,
struct flock64 __user *user)
{
return -EINVAL;
}
static inline int fcntl_setlk64(unsigned int fd, struct file *file,
unsigned int cmd, struct flock64 __user *user)
{
return -EACCES;
}
#endif
static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
{
return -EINVAL;
}
static inline int fcntl_getlease(struct file *filp)
{
return F_UNLCK;
}
static inline void
locks_free_lock_context(struct inode *inode)
{
}
static inline void locks_init_lock(struct file_lock *fl)
{
return;
}
static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl)
{
return;
}
static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl)
{
return;
}
static inline void locks_remove_posix(struct file *filp, fl_owner_t owner)
{
return;
}
static inline void locks_remove_file(struct file *filp)
{
return;
}
static inline void posix_test_lock(struct file *filp, struct file_lock *fl)
{
return;
}
static inline int posix_lock_file(struct file *filp, struct file_lock *fl,
struct file_lock *conflock)
{
return -ENOLCK;
}
static inline int posix_unblock_lock(struct file_lock *waiter)
{
return -ENOENT;
}
static inline int vfs_test_lock(struct file *filp, struct file_lock *fl)
{
return 0;
}
static inline int vfs_lock_file(struct file *filp, unsigned int cmd,
struct file_lock *fl, struct file_lock *conf)
{
return -ENOLCK;
}
static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
{
return 0;
}
static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl)
{
return -ENOLCK;
}
static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
{
return 0;
}
static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
{
return;
}
static inline int generic_setlease(struct file *filp, long arg,
struct file_lock **flp, void **priv)
{
return -EINVAL;
}
static inline int vfs_setlease(struct file *filp, long arg,
struct file_lock **lease, void **priv)
{
return -EINVAL;
}
static inline int lease_modify(struct file_lock *fl, int arg,
struct list_head *dispose)
{
return -EINVAL;
}
struct files_struct;
static inline void show_fd_locks(struct seq_file *f,
struct file *filp, struct files_struct *files) {}
#endif /* !CONFIG_FILE_LOCKING */
static inline struct inode *file_inode(const struct file *f)
{
return f->f_inode;
}
static inline struct dentry *file_dentry(const struct file *file)
{
return d_real(file->f_path.dentry, file_inode(file), 0);
}
static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
{
return locks_lock_inode_wait(locks_inode(filp), fl);
}
struct fasync_struct {
spinlock_t fa_lock;
int magic;
int fa_fd;
struct fasync_struct *fa_next; /* singly linked list */
struct file *fa_file;
struct rcu_head fa_rcu;
};
#define FASYNC_MAGIC 0x4601
/* SMP safe fasync helpers: */
extern int fasync_helper(int, struct file *, int, struct fasync_struct **);
extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *);
extern int fasync_remove_entry(struct file *, struct fasync_struct **);
extern struct fasync_struct *fasync_alloc(void);
extern void fasync_free(struct fasync_struct *);
/* can be called from interrupts */
extern void kill_fasync(struct fasync_struct **, int, int);
extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force);
extern void f_setown(struct file *filp, unsigned long arg, int force);
extern void f_delown(struct file *filp);
extern pid_t f_getown(struct file *filp);
extern int send_sigurg(struct fown_struct *fown);
struct mm_struct;
/*
* Umount options
*/
#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */
#define MNT_DETACH 0x00000002 /* Just detach from the tree */
#define MNT_EXPIRE 0x00000004 /* Mark for expiry */
#define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */
#define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused */
/* sb->s_iflags */
#define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */
#define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */
#define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */
/* sb->s_iflags to limit user namespace mounts */
#define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */
/* Possible states of 'frozen' field */
enum {
SB_UNFROZEN = 0, /* FS is unfrozen */
SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */
SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */
SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop
* internal threads if needed) */
SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */
};
#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)
struct sb_writers {
int frozen; /* Is sb frozen? */
wait_queue_head_t wait_unfrozen; /* for get_super_thawed() */
struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS];
};
struct super_block {
struct list_head s_list; /* Keep this first */
dev_t s_dev; /* search index; _not_ kdev_t */
unsigned char s_blocksize_bits;
unsigned long s_blocksize;
loff_t s_maxbytes; /* Max file size */
struct file_system_type *s_type;
const struct super_operations *s_op;
const struct dquot_operations *dq_op;
const struct quotactl_ops *s_qcop;
const struct export_operations *s_export_op;
unsigned long s_flags;
unsigned long s_iflags; /* internal SB_I_* flags */
unsigned long s_magic;
struct dentry *s_root;
struct rw_semaphore s_umount;
int s_count;
atomic_t s_active;
#ifdef CONFIG_SECURITY
void *s_security;
#endif
const struct xattr_handler **s_xattr;
const struct fscrypt_operations *s_cop;
struct hlist_bl_head s_anon; /* anonymous dentries for (nfs) exporting */
struct list_head s_mounts; /* list of mounts; _not_ for fs use */
struct block_device *s_bdev;
struct backing_dev_info *s_bdi;
struct mtd_info *s_mtd;
struct hlist_node s_instances;
unsigned int s_quota_types; /* Bitmask of supported quota types */
struct quota_info s_dquot; /* Diskquota specific options */
struct sb_writers s_writers;
char s_id[32]; /* Informational name */
u8 s_uuid[16]; /* UUID */
void *s_fs_info; /* Filesystem private info */
unsigned int s_max_links;
fmode_t s_mode;
/* Granularity of c/m/atime in ns.
Cannot be worse than a second */
u32 s_time_gran;
/*
* The next field is for VFS *only*. No filesystems have any business
* even looking at it. You had been warned.
*/
struct mutex s_vfs_rename_mutex; /* Kludge */
/*
* Filesystem subtype. If non-empty the filesystem type field
* in /proc/mounts will be "type.subtype"
*/
char *s_subtype;
/*
* Saved mount options for lazy filesystems using
* generic_show_options()
*/
char __rcu *s_options;
const struct dentry_operations *s_d_op; /* default d_op for dentries */
/*
* Saved pool identifier for cleancache (-1 means none)
*/
int cleancache_poolid;
struct shrinker s_shrink; /* per-sb shrinker handle */
/* Number of inodes with nlink == 0 but still referenced */
atomic_long_t s_remove_count;
/* Being remounted read-only */
int s_readonly_remount;
/* AIO completions deferred from interrupt context */
struct workqueue_struct *s_dio_done_wq;
struct hlist_head s_pins;
/*
* Owning user namespace and default context in which to
* interpret filesystem uids, gids, quotas, device nodes,
* xattrs and security labels.
*/
struct user_namespace *s_user_ns;
/*
* Keep the lru lists last in the structure so they always sit on their
* own individual cachelines.
*/
struct list_lru s_dentry_lru ____cacheline_aligned_in_smp;
struct list_lru s_inode_lru ____cacheline_aligned_in_smp;
struct rcu_head rcu;
struct work_struct destroy_work;
struct mutex s_sync_lock; /* sync serialisation lock */
/*
* Indicates how deep in a filesystem stack this SB is
*/
int s_stack_depth;
/* s_inode_list_lock protects s_inodes */
spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp;
struct list_head s_inodes; /* all inodes */
spinlock_t s_inode_wblist_lock;
struct list_head s_inodes_wb; /* writeback inodes */
};
/* Helper functions so that in most cases filesystems will
* not need to deal directly with kuid_t and kgid_t and can
* instead deal with the raw numeric values that are stored
* in the filesystem.
*/
static inline uid_t i_uid_read(const struct inode *inode)
{
return from_kuid(inode->i_sb->s_user_ns, inode->i_uid);
}
static inline gid_t i_gid_read(const struct inode *inode)
{
return from_kgid(inode->i_sb->s_user_ns, inode->i_gid);
}
static inline void i_uid_write(struct inode *inode, uid_t uid)
{
inode->i_uid = make_kuid(inode->i_sb->s_user_ns, uid);
}
static inline void i_gid_write(struct inode *inode, gid_t gid)
{
inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid);
}
extern struct timespec current_fs_time(struct super_block *sb);
extern struct timespec current_time(struct inode *inode);
/*
* Snapshotting support.
*/
void __sb_end_write(struct super_block *sb, int level);
int __sb_start_write(struct super_block *sb, int level, bool wait);
#define __sb_writers_acquired(sb, lev) \
percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
#define __sb_writers_release(sb, lev) \
percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
/**
* sb_end_write - drop write access to a superblock
* @sb: the super we wrote to
*
* Decrement number of writers to the filesystem. Wake up possible waiters
* wanting to freeze the filesystem.
*/
static inline void sb_end_write(struct super_block *sb)
{
__sb_end_write(sb, SB_FREEZE_WRITE);
}
/**
* sb_end_pagefault - drop write access to a superblock from a page fault
* @sb: the super we wrote to
*
* Decrement number of processes handling write page fault to the filesystem.
* Wake up possible waiters wanting to freeze the filesystem.
*/
static inline void sb_end_pagefault(struct super_block *sb)
{
__sb_end_write(sb, SB_FREEZE_PAGEFAULT);
}
/**
* sb_end_intwrite - drop write access to a superblock for internal fs purposes
* @sb: the super we wrote to
*
* Decrement fs-internal number of writers to the filesystem. Wake up possible
* waiters wanting to freeze the filesystem.
*/
static inline void sb_end_intwrite(struct super_block *sb)
{
__sb_end_write(sb, SB_FREEZE_FS);
}
/**
* sb_start_write - get write access to a superblock
* @sb: the super we write to
*
* When a process wants to write data or metadata to a file system (i.e. dirty
* a page or an inode), it should embed the operation in a sb_start_write() -
* sb_end_write() pair to get exclusion against file system freezing. This
* function increments number of writers preventing freezing. If the file
* system is already frozen, the function waits until the file system is
* thawed.
*
* Since freeze protection behaves as a lock, users have to preserve
* ordering of freeze protection and other filesystem locks. Generally,
* freeze protection should be the outermost lock. In particular, we have:
*
* sb_start_write
* -> i_mutex (write path, truncate, directory ops, ...)
* -> s_umount (freeze_super, thaw_super)
*/
static inline void sb_start_write(struct super_block *sb)
{
__sb_start_write(sb, SB_FREEZE_WRITE, true);
}
static inline int sb_start_write_trylock(struct super_block *sb)
{
return __sb_start_write(sb, SB_FREEZE_WRITE, false);
}
/**
* sb_start_pagefault - get write access to a superblock from a page fault
* @sb: the super we write to
*
* When a process starts handling write page fault, it should embed the
* operation into sb_start_pagefault() - sb_end_pagefault() pair to get
* exclusion against file system freezing. This is needed since the page fault
* is going to dirty a page. This function increments number of running page
* faults preventing freezing. If the file system is already frozen, the
* function waits until the file system is thawed.
*
* Since page fault freeze protection behaves as a lock, users have to preserve
* ordering of freeze protection and other filesystem locks. It is advised to
* put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
* handling code implies lock dependency:
*
* mmap_sem
* -> sb_start_pagefault
*/
static inline void sb_start_pagefault(struct super_block *sb)
{
__sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
}
/*
* sb_start_intwrite - get write access to a superblock for internal fs purposes
* @sb: the super we write to
*
* This is the third level of protection against filesystem freezing. It is
* free for use by a filesystem. The only requirement is that it must rank
* below sb_start_pagefault.
*
* For example filesystem can call sb_start_intwrite() when starting a
* transaction which somewhat eases handling of freezing for internal sources
* of filesystem changes (internal fs threads, discarding preallocation on file
* close, etc.).
*/
static inline void sb_start_intwrite(struct super_block *sb)
{
__sb_start_write(sb, SB_FREEZE_FS, true);
}
extern bool inode_owner_or_capable(const struct inode *inode);
/*
* VFS helper functions..
*/
extern int vfs_create(struct inode *, struct dentry *, umode_t, bool);
extern int vfs_mkdir(struct inode *, struct dentry *, umode_t);
extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t);
extern int vfs_symlink(struct inode *, struct dentry *, const char *);
extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **);
extern int vfs_rmdir(struct inode *, struct dentry *);
extern int vfs_unlink(struct inode *, struct dentry *, struct inode **);
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);
extern int vfs_whiteout(struct inode *, struct dentry *);
/*
* VFS file helper functions.
*/
extern void inode_init_owner(struct inode *inode, const struct inode *dir,
umode_t mode);
extern bool may_open_dev(const struct path *path);
/*
* VFS FS_IOC_FIEMAP helper definitions.
*/
struct fiemap_extent_info {
unsigned int fi_flags; /* Flags as passed from user */
unsigned int fi_extents_mapped; /* Number of mapped extents */
unsigned int fi_extents_max; /* Size of fiemap_extent array */
struct fiemap_extent __user *fi_extents_start; /* Start of
fiemap_extent array */
};
int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
u64 phys, u64 len, u32 flags);
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
/*
* File types
*
* NOTE! These match bits 12..15 of stat.st_mode
* (ie "(i_mode >> 12) & 15").
*/
#define DT_UNKNOWN 0
#define DT_FIFO 1
#define DT_CHR 2
#define DT_DIR 4
#define DT_BLK 6
#define DT_REG 8
#define DT_LNK 10
#define DT_SOCK 12
#define DT_WHT 14
/*
* This is the "filldir" function type, used by readdir() to let
* the kernel specify what kind of dirent layout it wants to have.
* This allows the kernel to read directories into kernel space or
* to have different dirent layouts depending on the binary type.
*/
struct dir_context;
typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,
unsigned);
struct dir_context {
const filldir_t actor;
loff_t pos;
};
struct block_device_operations;
/* These macros are for out of kernel modules to test that
* the kernel supports the unlocked_ioctl and compat_ioctl
* fields in struct file_operations. */
#define HAVE_COMPAT_IOCTL 1
#define HAVE_UNLOCKED_IOCTL 1
/*
* These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems.
*
* NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
* NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
* NOMMU_MAP_READ: Can be mapped for reading
* NOMMU_MAP_WRITE: Can be mapped for writing
* NOMMU_MAP_EXEC: Can be mapped for execution
*/
#define NOMMU_MAP_COPY 0x00000001
#define NOMMU_MAP_DIRECT 0x00000008
#define NOMMU_MAP_READ VM_MAYREAD
#define NOMMU_MAP_WRITE VM_MAYWRITE
#define NOMMU_MAP_EXEC VM_MAYEXEC
#define NOMMU_VMFLAGS \
(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
struct iov_iter;
struct file_operations {
struct module *owner;
loff_t (*llseek) (struct file *, loff_t, int);
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
int (*iterate) (struct file *, struct dir_context *);
int (*iterate_shared) (struct file *, struct dir_context *);
unsigned int (*poll) (struct file *, struct poll_table_struct *);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
int (*fsync) (struct file *, loff_t, loff_t, int datasync);
int (*fasync) (int, struct file *, int);
int (*lock) (struct file *, int, struct file_lock *);
ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
int (*check_flags)(int);
int (*flock) (struct file *, int, struct file_lock *);
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
int (*setlease)(struct file *, long, struct file_lock **, void **);
long (*fallocate)(struct file *file, int mode, loff_t offset,
loff_t len);
void (*show_fdinfo)(struct seq_file *m, struct file *f);
#ifndef CONFIG_MMU
unsigned (*mmap_capabilities)(struct file *);
#endif
ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
loff_t, size_t, unsigned int);
int (*clone_file_range)(struct file *, loff_t, struct file *, loff_t,
u64);
ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *,
u64);
};
struct inode_operations {
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);
int (*permission) (struct inode *, int);
struct posix_acl * (*get_acl)(struct inode *, int);
int (*readlink) (struct dentry *, char __user *,int);
int (*create) (struct inode *,struct dentry *, umode_t, bool);
int (*link) (struct dentry *,struct inode *,struct dentry *);
int (*unlink) (struct inode *,struct dentry *);
int (*symlink) (struct inode *,struct dentry *,const char *);
int (*mkdir) (struct inode *,struct dentry *,umode_t);
int (*rmdir) (struct inode *,struct dentry *);
int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
ssize_t (*listxattr) (struct dentry *, char *, size_t);
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
u64 len);
int (*update_time)(struct inode *, struct timespec *, int);
int (*atomic_open)(struct inode *, struct dentry *,
struct file *, unsigned open_flag,
umode_t create_mode, int *opened);
int (*tmpfile) (struct inode *, struct dentry *, umode_t);
int (*set_acl)(struct inode *, struct posix_acl *, int);
} ____cacheline_aligned;
ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
unsigned long nr_segs, unsigned long fast_segs,
struct iovec *fast_pointer,
struct iovec **ret_pointer);
extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t __vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);
extern ssize_t vfs_readv(struct file *, const struct iovec __user *,
unsigned long, loff_t *, int);
extern ssize_t vfs_writev(struct file *, const struct iovec __user *,
unsigned long, loff_t *, int);
extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,
loff_t, size_t, unsigned int);
extern int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out, u64 len);
extern int vfs_dedupe_file_range(struct file *file,
struct file_dedupe_range *same);
struct super_operations {
struct inode *(*alloc_inode)(struct super_block *sb);
void (*destroy_inode)(struct inode *);
void (*dirty_inode) (struct inode *, int flags);
int (*write_inode) (struct inode *, struct writeback_control *wbc);
int (*drop_inode) (struct inode *);
void (*evict_inode) (struct inode *);
void (*put_super) (struct super_block *);
int (*sync_fs)(struct super_block *sb, int wait);
int (*freeze_super) (struct super_block *);
int (*freeze_fs) (struct super_block *);
int (*thaw_super) (struct super_block *);
int (*unfreeze_fs) (struct super_block *);
int (*statfs) (struct dentry *, struct kstatfs *);
int (*remount_fs) (struct super_block *, int *, char *);
void (*umount_begin) (struct super_block *);
int (*show_options)(struct seq_file *, struct dentry *);
int (*show_devname)(struct seq_file *, struct dentry *);
int (*show_path)(struct seq_file *, struct dentry *);
int (*show_stats)(struct seq_file *, struct dentry *);
#ifdef CONFIG_QUOTA
ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
struct dquot **(*get_dquots)(struct inode *);
#endif
int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
long (*nr_cached_objects)(struct super_block *,
struct shrink_control *);
long (*free_cached_objects)(struct super_block *,
struct shrink_control *);
};
/*
* Inode flags - they have no relation to superblock flags now
*/
#define S_SYNC 1 /* Writes are synced at once */
#define S_NOATIME 2 /* Do not update access times */
#define S_APPEND 4 /* Append-only file */
#define S_IMMUTABLE 8 /* Immutable file */
#define S_DEAD 16 /* removed, but still open directory */
#define S_NOQUOTA 32 /* Inode is not counted to quota */
#define S_DIRSYNC 64 /* Directory modifications are synchronous */
#define S_NOCMTIME 128 /* Do not update file c/mtime */
#define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */
#define S_PRIVATE 512 /* Inode is fs-internal */
#define S_IMA 1024 /* Inode has an associated IMA struct */
#define S_AUTOMOUNT 2048 /* Automount/referral quasi-directory */
#define S_NOSEC 4096 /* no suid or xattr security attributes */
#ifdef CONFIG_FS_DAX
#define S_DAX 8192 /* Direct Access, avoiding the page cache */
#else
#define S_DAX 0 /* Make all the DAX code disappear */
#endif
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
* flags just means all the inodes inherit those flags by default. It might be
* possible to override it selectively if you really wanted to with some
* ioctl() that is not currently implemented.
*
* Exception: MS_RDONLY is always applied to the entire file system.
*
* Unfortunately, it is possible to change a filesystems flags with it mounted
* with files in use. This means that all of the inodes will not have their
* i_flags updated. Hence, i_flags no longer inherit the superblock mount
* flags, so these have to be checked separately. -- rmk@arm.uk.linux.org
*/
#define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg))
#define IS_RDONLY(inode) ((inode)->i_sb->s_flags & MS_RDONLY)
#define IS_SYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS) || \
((inode)->i_flags & S_SYNC))
#define IS_DIRSYNC(inode) (__IS_FLG(inode, MS_SYNCHRONOUS|MS_DIRSYNC) || \
((inode)->i_flags & (S_SYNC|S_DIRSYNC)))
#define IS_MANDLOCK(inode) __IS_FLG(inode, MS_MANDLOCK)
#define IS_NOATIME(inode) __IS_FLG(inode, MS_RDONLY|MS_NOATIME)
#define IS_I_VERSION(inode) __IS_FLG(inode, MS_I_VERSION)
#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA)
#define IS_APPEND(inode) ((inode)->i_flags & S_APPEND)
#define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE)
#define IS_POSIXACL(inode) __IS_FLG(inode, MS_POSIXACL)
#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD)
#define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME)
#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE)
#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE)
#define IS_IMA(inode) ((inode)->i_flags & S_IMA)
#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC)
#define IS_DAX(inode) ((inode)->i_flags & S_DAX)
#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \
(inode)->i_rdev == WHITEOUT_DEV)
static inline bool HAS_UNMAPPED_ID(struct inode *inode)
{
return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid);
}
/*
* Inode state bits. Protected by inode->i_lock
*
* Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
* I_DIRTY_DATASYNC and I_DIRTY_PAGES.
*
* Four bits define the lifetime of an inode. Initially, inodes are I_NEW,
* until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at
* various stages of removing an inode.
*
* Two bits are used for locking and completion notification, I_NEW and I_SYNC.
*
* I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on
* fdatasync(). i_atime is the usual cause.
* I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of
* these changes separately from I_DIRTY_SYNC so that we
* don't have to write inode on fdatasync() when only
* mtime has changed in it.
* I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean.
* I_NEW Serves as both a mutex and completion notification.
* New inodes set I_NEW. If two processes both create
* the same inode, one of them will release its inode and
* wait for I_NEW to be released before returning.
* Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
* also cause waiting on I_NEW, without I_NEW actually
* being set. find_inode() uses this to prevent returning
* nearly-dead inodes.
* I_WILL_FREE Must be set when calling write_inode_now() if i_count
* is zero. I_FREEING must be set when I_WILL_FREE is
* cleared.
* I_FREEING Set when inode is about to be freed but still has dirty
* pages or buffers attached or the inode itself is still
* dirty.
* I_CLEAR Added by clear_inode(). In this state the inode is
* clean and can be destroyed. Inode keeps I_FREEING.
*
* Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
* prohibited for many purposes. iget() must wait for
* the inode to be completely released, then create it
* anew. Other functions will just ignore such inodes,
* if appropriate. I_NEW is used for waiting.
*
* I_SYNC Writeback of inode is running. The bit is set during
* data writeback, and cleared with a wakeup on the bit
* address once it is done. The bit is also used to pin
* the inode in memory for flusher thread.
*
* I_REFERENCED Marks the inode as recently references on the LRU list.
*
* I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit().
*
* I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to
* synchronize competing switching instances and to tell
* wb stat updates to grab mapping->tree_lock. See
* inode_switch_wb_work_fn() for details.
*
* Q: What is the difference between I_WILL_FREE and I_FREEING?
*/
#define I_DIRTY_SYNC (1 << 0)
#define I_DIRTY_DATASYNC (1 << 1)
#define I_DIRTY_PAGES (1 << 2)
#define __I_NEW 3
#define I_NEW (1 << __I_NEW)
#define I_WILL_FREE (1 << 4)
#define I_FREEING (1 << 5)
#define I_CLEAR (1 << 6)
#define __I_SYNC 7
#define I_SYNC (1 << __I_SYNC)
#define I_REFERENCED (1 << 8)
#define __I_DIO_WAKEUP 9
#define I_DIO_WAKEUP (1 << __I_DIO_WAKEUP)
#define I_LINKABLE (1 << 10)
#define I_DIRTY_TIME (1 << 11)
#define __I_DIRTY_TIME_EXPIRED 12
#define I_DIRTY_TIME_EXPIRED (1 << __I_DIRTY_TIME_EXPIRED)
#define I_WB_SWITCH (1 << 13)
#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
#define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
extern void __mark_inode_dirty(struct inode *, int);
static inline void mark_inode_dirty(struct inode *inode)
{
__mark_inode_dirty(inode, I_DIRTY);
}
static inline void mark_inode_dirty_sync(struct inode *inode)
{
__mark_inode_dirty(inode, I_DIRTY_SYNC);
}
extern void inc_nlink(struct inode *inode);
extern void drop_nlink(struct inode *inode);
extern void clear_nlink(struct inode *inode);
extern void set_nlink(struct inode *inode, unsigned int nlink);
static inline void inode_inc_link_count(struct inode *inode)
{
inc_nlink(inode);
mark_inode_dirty(inode);
}
static inline void inode_dec_link_count(struct inode *inode)
{
drop_nlink(inode);
mark_inode_dirty(inode);
}
/**
* inode_inc_iversion - increments i_version
* @inode: inode that need to be updated
*
* Every time the inode is modified, the i_version field will be incremented.
* The filesystem has to be mounted with i_version flag
*/
static inline void inode_inc_iversion(struct inode *inode)
{
spin_lock(&inode->i_lock);
inode->i_version++;
spin_unlock(&inode->i_lock);
}
enum file_time_flags {
S_ATIME = 1,
S_MTIME = 2,
S_CTIME = 4,
S_VERSION = 8,
};
extern void touch_atime(const struct path *);
static inline void file_accessed(struct file *file)
{
if (!(file->f_flags & O_NOATIME))
touch_atime(&file->f_path);
}
int sync_inode(struct inode *inode, struct writeback_control *wbc);
int sync_inode_metadata(struct inode *inode, int wait);
struct file_system_type {
const char *name;
int fs_flags;
#define FS_REQUIRES_DEV 1
#define FS_BINARY_MOUNTDATA 2
#define FS_HAS_SUBTYPE 4
#define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */
#define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */
struct dentry *(*mount) (struct file_system_type *, int,
const char *, void *);
void (*kill_sb) (struct super_block *);
struct module *owner;
struct file_system_type * next;
struct hlist_head fs_supers;
struct lock_class_key s_lock_key;
struct lock_class_key s_umount_key;
struct lock_class_key s_vfs_rename_key;
struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];
struct lock_class_key i_lock_key;
struct lock_class_key i_mutex_key;
struct lock_class_key i_mutex_dir_key;
};
#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)
extern struct dentry *mount_ns(struct file_system_type *fs_type,
int flags, void *data, void *ns, struct user_namespace *user_ns,
int (*fill_super)(struct super_block *, void *, int));
extern struct dentry *mount_bdev(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern struct dentry *mount_nodev(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int));
extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
void kill_anon_super(struct super_block *sb);
void kill_litter_super(struct super_block *sb);
void deactivate_super(struct super_block *sb);
void deactivate_locked_super(struct super_block *sb);
int set_anon_super(struct super_block *s, void *data);
int get_anon_bdev(dev_t *);
void free_anon_bdev(dev_t);
struct super_block *sget_userns(struct file_system_type *type,
int (*test)(struct super_block *,void *),
int (*set)(struct super_block *,void *),
int flags, struct user_namespace *user_ns,
void *data);
struct super_block *sget(struct file_system_type *type,
int (*test)(struct super_block *,void *),
int (*set)(struct super_block *,void *),
int flags, void *data);
extern struct dentry *mount_pseudo_xattr(struct file_system_type *, char *,
const struct super_operations *ops,
const struct xattr_handler **xattr,
const struct dentry_operations *dops,
unsigned long);
static inline struct dentry *
mount_pseudo(struct file_system_type *fs_type, char *name,
const struct super_operations *ops,
const struct dentry_operations *dops, unsigned long magic)
{
return mount_pseudo_xattr(fs_type, name, ops, NULL, dops, magic);
}
/* Alas, no aliases. Too much hassle with bringing module.h everywhere */
#define fops_get(fops) \
(((fops) && try_module_get((fops)->owner) ? (fops) : NULL))
#define fops_put(fops) \
do { if (fops) module_put((fops)->owner); } while(0)
/*
* This one is to be used *ONLY* from ->open() instances.
* fops must be non-NULL, pinned down *and* module dependencies
* should be sufficient to pin the caller down as well.
*/
#define replace_fops(f, fops) \
do { \
struct file *__file = (f); \
fops_put(__file->f_op); \
BUG_ON(!(__file->f_op = (fops))); \
} while(0)
extern int register_filesystem(struct file_system_type *);
extern int unregister_filesystem(struct file_system_type *);
extern struct vfsmount *kern_mount_data(struct file_system_type *, void *data);
#define kern_mount(type) kern_mount_data(type, NULL)
extern void kern_unmount(struct vfsmount *mnt);
extern int may_umount_tree(struct vfsmount *);
extern int may_umount(struct vfsmount *);
extern long do_mount(const char *, const char __user *,
const char *, unsigned long, void *);
extern struct vfsmount *collect_mounts(const struct path *);
extern void drop_collected_mounts(struct vfsmount *);
extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,
struct vfsmount *);
extern int vfs_statfs(const struct path *, struct kstatfs *);
extern int user_statfs(const char __user *, struct kstatfs *);
extern int fd_statfs(int, struct kstatfs *);
extern int vfs_ustat(dev_t, struct kstatfs *);
extern int freeze_super(struct super_block *super);
extern int thaw_super(struct super_block *super);
extern bool our_mnt(struct vfsmount *mnt);
extern int current_umask(void);
extern void ihold(struct inode * inode);
extern void iput(struct inode *);
extern int generic_update_time(struct inode *, struct timespec *, int);
/* /sys/fs */
extern struct kobject *fs_kobj;
#define MAX_RW_COUNT (INT_MAX & PAGE_MASK)
#ifdef CONFIG_MANDATORY_FILE_LOCKING
extern int locks_mandatory_locked(struct file *);
extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);
/*
* Candidates for mandatory locking have the setgid bit set
* but no group execute bit - an otherwise meaningless combination.
*/
static inline int __mandatory_lock(struct inode *ino)
{
return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
}
/*
* ... and these candidates should be on MS_MANDLOCK mounted fs,
* otherwise these will be advisory locks
*/
static inline int mandatory_lock(struct inode *ino)
{
return IS_MANDLOCK(ino) && __mandatory_lock(ino);
}
static inline int locks_verify_locked(struct file *file)
{
if (mandatory_lock(locks_inode(file)))
return locks_mandatory_locked(file);
return 0;
}
static inline int locks_verify_truncate(struct inode *inode,
struct file *f,
loff_t size)
{
if (!inode->i_flctx || !mandatory_lock(inode))
return 0;
if (size < inode->i_size) {
return locks_mandatory_area(inode, f, size, inode->i_size - 1,
F_WRLCK);
} else {
return locks_mandatory_area(inode, f, inode->i_size, size - 1,
F_WRLCK);
}
}
#else /* !CONFIG_MANDATORY_FILE_LOCKING */
static inline int locks_mandatory_locked(struct file *file)
{
return 0;
}
static inline int locks_mandatory_area(struct inode *inode, struct file *filp,
loff_t start, loff_t end, unsigned char type)
{
return 0;
}
static inline int __mandatory_lock(struct inode *inode)
{
return 0;
}
static inline int mandatory_lock(struct inode *inode)
{
return 0;
}
static inline int locks_verify_locked(struct file *file)
{
return 0;
}
static inline int locks_verify_truncate(struct inode *inode, struct file *filp,
size_t size)
{
return 0;
}
#endif /* CONFIG_MANDATORY_FILE_LOCKING */
#ifdef CONFIG_FILE_LOCKING
static inline int break_lease(struct inode *inode, unsigned int mode)
{
/*
* Since this check is lockless, we must ensure that any refcounts
* taken are done before checking i_flctx->flc_lease. Otherwise, we
* could end up racing with tasks trying to set a new lease on this
* file.
*/
smp_mb();
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
return __break_lease(inode, mode, FL_LEASE);
return 0;
}
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
/*
* Since this check is lockless, we must ensure that any refcounts
* taken are done before checking i_flctx->flc_lease. Otherwise, we
* could end up racing with tasks trying to set a new lease on this
* file.
*/
smp_mb();
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
return __break_lease(inode, mode, FL_DELEG);
return 0;
}
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
int ret;
ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);
if (ret == -EWOULDBLOCK && delegated_inode) {
*delegated_inode = inode;
ihold(inode);
}
return ret;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
int ret;
ret = break_deleg(*delegated_inode, O_WRONLY);
iput(*delegated_inode);
*delegated_inode = NULL;
return ret;
}
static inline int break_layout(struct inode *inode, bool wait)
{
smp_mb();
if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))
return __break_lease(inode,
wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,
FL_LAYOUT);
return 0;
}
#else /* !CONFIG_FILE_LOCKING */
static inline int break_lease(struct inode *inode, unsigned int mode)
{
return 0;
}
static inline int break_deleg(struct inode *inode, unsigned int mode)
{
return 0;
}
static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode)
{
return 0;
}
static inline int break_deleg_wait(struct inode **delegated_inode)
{
BUG();
return 0;
}
static inline int break_layout(struct inode *inode, bool wait)
{
return 0;
}
#endif /* CONFIG_FILE_LOCKING */
/* fs/open.c */
struct audit_names;
struct filename {
const char *name; /* pointer to actual string */
const __user char *uptr; /* original userland pointer */
struct audit_names *aname;
int refcnt;
const char iname[];
};
extern long vfs_truncate(const struct path *, loff_t);
extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,
struct file *filp);
extern int vfs_fallocate(struct file *file, int mode, loff_t offset,
loff_t len);
extern long do_sys_open(int dfd, const char __user *filename, int flags,
umode_t mode);
extern struct file *file_open_name(struct filename *, int, umode_t);
extern struct file *filp_open(const char *, int, umode_t);
extern struct file *file_open_root(struct dentry *, struct vfsmount *,
const char *, int, umode_t);
extern struct file * dentry_open(const struct path *, int, const struct cred *);
extern int filp_close(struct file *, fl_owner_t id);
extern struct filename *getname_flags(const char __user *, int, int *);
extern struct filename *getname(const char __user *);
extern struct filename *getname_kernel(const char *);
extern void putname(struct filename *name);
enum {
FILE_CREATED = 1,
FILE_OPENED = 2
};
extern int finish_open(struct file *file, struct dentry *dentry,
int (*open)(struct inode *, struct file *),
int *opened);
extern int finish_no_open(struct file *file, struct dentry *dentry);
/* fs/ioctl.c */
extern int ioctl_preallocate(struct file *filp, void __user *argp);
/* fs/dcache.c */
extern void __init vfs_caches_init_early(void);
extern void __init vfs_caches_init(void);
extern struct kmem_cache *names_cachep;
#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL)
#define __putname(name) kmem_cache_free(names_cachep, (void *)(name))
#ifdef CONFIG_BLOCK
extern int register_blkdev(unsigned int, const char *);
extern void unregister_blkdev(unsigned int, const char *);
extern struct block_device *bdget(dev_t);
extern struct block_device *bdgrab(struct block_device *bdev);
extern void bd_set_size(struct block_device *, loff_t size);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
extern void invalidate_bdev(struct block_device *);
extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
extern int sync_blockdev(struct block_device *bdev);
extern void kill_bdev(struct block_device *);
extern struct super_block *freeze_bdev(struct block_device *);
extern void emergency_thaw_all(void);
extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
extern int fsync_bdev(struct block_device *);
extern struct super_block *blockdev_superblock;
static inline bool sb_is_blkdev_sb(struct super_block *sb)
{
return sb == blockdev_superblock;
}
#else
static inline void bd_forget(struct inode *inode) {}
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
static inline void kill_bdev(struct block_device *bdev) {}
static inline void invalidate_bdev(struct block_device *bdev) {}
static inline struct super_block *freeze_bdev(struct block_device *sb)
{
return NULL;
}
static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
{
return 0;
}
static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg)
{
}
static inline bool sb_is_blkdev_sb(struct super_block *sb)
{
return false;
}
#endif
extern int sync_filesystem(struct super_block *);
extern const struct file_operations def_blk_fops;
extern const struct file_operations def_chr_fops;
#ifdef CONFIG_BLOCK
extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long);
extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder);
extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
void *holder);
extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
void *holder);
extern void blkdev_put(struct block_device *bdev, fmode_t mode);
extern int __blkdev_reread_part(struct block_device *bdev);
extern int blkdev_reread_part(struct block_device *bdev);
#ifdef CONFIG_SYSFS
extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
extern void bd_unlink_disk_holder(struct block_device *bdev,
struct gendisk *disk);
#else
static inline int bd_link_disk_holder(struct block_device *bdev,
struct gendisk *disk)
{
return 0;
}
static inline void bd_unlink_disk_holder(struct block_device *bdev,
struct gendisk *disk)
{
}
#endif
#endif
/* fs/char_dev.c */
#define CHRDEV_MAJOR_HASH_SIZE 255
/* Marks the bottom of the first segment of free char majors */
#define CHRDEV_MAJOR_DYN_END 234
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
extern int register_chrdev_region(dev_t, unsigned, const char *);
extern int __register_chrdev(unsigned int major, unsigned int baseminor,
unsigned int count, const char *name,
const struct file_operations *fops);
extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
unsigned int count, const char *name);
extern void unregister_chrdev_region(dev_t, unsigned);
extern void chrdev_show(struct seq_file *,off_t);
static inline int register_chrdev(unsigned int major, const char *name,
const struct file_operations *fops)
{
return __register_chrdev(major, 0, 256, name, fops);
}
static inline void unregister_chrdev(unsigned int major, const char *name)
{
__unregister_chrdev(major, 0, 256, name);
}
/* fs/block_dev.c */
#define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */
#define BDEVT_SIZE 10 /* Largest string for MAJ:MIN for blkdev */
#ifdef CONFIG_BLOCK
#define BLKDEV_MAJOR_HASH_SIZE 255
extern const char *__bdevname(dev_t, char *buffer);
extern const char *bdevname(struct block_device *bdev, char *buffer);
extern struct block_device *lookup_bdev(const char *);
extern void blkdev_show(struct seq_file *,off_t);
#else
#define BLKDEV_MAJOR_HASH_SIZE 0
#endif
extern void init_special_inode(struct inode *, umode_t, dev_t);
/* Invalid inode operations -- fs/bad_inode.c */
extern void make_bad_inode(struct inode *);
extern bool is_bad_inode(struct inode *);
#ifdef CONFIG_BLOCK
static inline bool op_is_write(unsigned int op)
{
return op == REQ_OP_READ ? false : true;
}
/*
* return data direction, READ or WRITE
*/
static inline int bio_data_dir(struct bio *bio)
{
return op_is_write(bio_op(bio)) ? WRITE : READ;
}
extern void check_disk_size_change(struct gendisk *disk,
struct block_device *bdev);
extern int revalidate_disk(struct gendisk *);
extern int check_disk_change(struct block_device *);
extern int __invalidate_device(struct block_device *, bool);
extern int invalidate_partition(struct gendisk *, int);
#endif
unsigned long invalidate_mapping_pages(struct address_space *mapping,
pgoff_t start, pgoff_t end);
static inline void invalidate_remote_inode(struct inode *inode)
{
if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode))
invalidate_mapping_pages(inode->i_mapping, 0, -1);
}
extern int invalidate_inode_pages2(struct address_space *mapping);
extern int invalidate_inode_pages2_range(struct address_space *mapping,
pgoff_t start, pgoff_t end);
extern int write_inode_now(struct inode *, int);
extern int filemap_fdatawrite(struct address_space *);
extern int filemap_flush(struct address_space *);
extern int filemap_fdatawait(struct address_space *);
extern void filemap_fdatawait_keep_errors(struct address_space *);
extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,
loff_t lend);
extern int filemap_write_and_wait(struct address_space *mapping);
extern int filemap_write_and_wait_range(struct address_space *mapping,
loff_t lstart, loff_t lend);
extern int __filemap_fdatawrite_range(struct address_space *mapping,
loff_t start, loff_t end, int sync_mode);
extern int filemap_fdatawrite_range(struct address_space *mapping,
loff_t start, loff_t end);
extern int filemap_check_errors(struct address_space *mapping);
extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,
int datasync);
extern int vfs_fsync(struct file *file, int datasync);
/*
* Sync the bytes written if this was a synchronous write. Expect ki_pos
* to already be updated for the write, and will return either the amount
* of bytes passed in, or an error if syncing the file failed.
*/
static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
{
if (iocb->ki_flags & IOCB_DSYNC) {
int ret = vfs_fsync_range(iocb->ki_filp,
iocb->ki_pos - count, iocb->ki_pos - 1,
(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
if (ret)
return ret;
}
return count;
}
extern void emergency_sync(void);
extern void emergency_remount(void);
#ifdef CONFIG_BLOCK
extern sector_t bmap(struct inode *, sector_t);
#endif
extern int notify_change(struct dentry *, struct iattr *, struct inode **);
extern int inode_permission(struct inode *, int);
extern int __inode_permission(struct inode *, int);
extern int generic_permission(struct inode *, int);
extern int __check_sticky(struct inode *dir, struct inode *inode);
static inline bool execute_ok(struct inode *inode)
{
return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode);
}
static inline void file_start_write(struct file *file)
{
if (!S_ISREG(file_inode(file)->i_mode))
return;
__sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
}
static inline bool file_start_write_trylock(struct file *file)
{
if (!S_ISREG(file_inode(file)->i_mode))
return true;
return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
}
static inline void file_end_write(struct file *file)
{
if (!S_ISREG(file_inode(file)->i_mode))
return;
__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
}
/*
* get_write_access() gets write permission for a file.
* put_write_access() releases this write permission.
* This is used for regular files.
* We cannot support write (and maybe mmap read-write shared) accesses and
* MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode
* can have the following values:
* 0: no writers, no VM_DENYWRITE mappings
* < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist
* > 0: (i_writecount) users are writing to the file.
*
* Normally we operate on that counter with atomic_{inc,dec} and it's safe
* except for the cases where we don't hold i_writecount yet. Then we need to
* use {get,deny}_write_access() - these functions check the sign and refuse
* to do the change if sign is wrong.
*/
static inline int get_write_access(struct inode *inode)
{
return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
}
static inline int deny_write_access(struct file *file)
{
struct inode *inode = file_inode(file);
return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY;
}
static inline void put_write_access(struct inode * inode)
{
atomic_dec(&inode->i_writecount);
}
static inline void allow_write_access(struct file *file)
{
if (file)
atomic_inc(&file_inode(file)->i_writecount);
}
static inline bool inode_is_open_for_write(const struct inode *inode)
{
return atomic_read(&inode->i_writecount) > 0;
}
#ifdef CONFIG_IMA
static inline void i_readcount_dec(struct inode *inode)
{
BUG_ON(!atomic_read(&inode->i_readcount));
atomic_dec(&inode->i_readcount);
}
static inline void i_readcount_inc(struct inode *inode)
{
atomic_inc(&inode->i_readcount);
}
#else
static inline void i_readcount_dec(struct inode *inode)
{
return;
}
static inline void i_readcount_inc(struct inode *inode)
{
return;
}
#endif
extern int do_pipe_flags(int *, int);
#define __kernel_read_file_id(id) \
id(UNKNOWN, unknown) \
id(FIRMWARE, firmware) \
id(FIRMWARE_PREALLOC_BUFFER, firmware) \
id(MODULE, kernel-module) \
id(KEXEC_IMAGE, kexec-image) \
id(KEXEC_INITRAMFS, kexec-initramfs) \
id(POLICY, security-policy) \
id(MAX_ID, )
#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
#define __fid_stringify(dummy, str) #str,
enum kernel_read_file_id {
__kernel_read_file_id(__fid_enumify)
};
static const char * const kernel_read_file_str[] = {
__kernel_read_file_id(__fid_stringify)
};
static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id)
{
if (id < 0 || id >= READING_MAX_ID)
return kernel_read_file_str[READING_UNKNOWN];
return kernel_read_file_str[id];
}
extern int kernel_read(struct file *, loff_t, char *, unsigned long);
extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,
enum kernel_read_file_id);
extern int kernel_read_file_from_path(char *, void **, loff_t *, loff_t,
enum kernel_read_file_id);
extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
enum kernel_read_file_id);
extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t);
extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
extern struct file * open_exec(const char *);
/* fs/dcache.c -- generic fs support functions */
extern bool is_subdir(struct dentry *, struct dentry *);
extern bool path_is_under(const struct path *, const struct path *);
extern char *file_path(struct file *, char *, int);
#include <linux/err.h>
/* needed for stackable file system support */
extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
extern int inode_init_always(struct super_block *, struct inode *);
extern void inode_init_once(struct inode *);
extern void address_space_init_once(struct address_space *mapping);
extern struct inode * igrab(struct inode *);
extern ino_t iunique(struct super_block *, ino_t);
extern int inode_needs_sync(struct inode *inode);
extern int generic_delete_inode(struct inode *inode);
static inline int generic_drop_inode(struct inode *inode)
{
return !inode->i_nlink || inode_unhashed(inode);
}
extern struct inode *ilookup5_nowait(struct super_block *sb,
unsigned long hashval, int (*test)(struct inode *, void *),
void *data);
extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,
int (*test)(struct inode *, void *), void *data);
extern struct inode *ilookup(struct super_block *sb, unsigned long ino);
extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *);
extern struct inode * iget_locked(struct super_block *, unsigned long);
extern struct inode *find_inode_nowait(struct super_block *,
unsigned long,
int (*match)(struct inode *,
unsigned long, void *),
void *data);
extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *);
extern int insert_inode_locked(struct inode *);
#ifdef CONFIG_DEBUG_LOCK_ALLOC
extern void lockdep_annotate_inode_mutex_key(struct inode *inode);
#else
static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { };
#endif
extern void unlock_new_inode(struct inode *);
extern unsigned int get_next_ino(void);
extern void __iget(struct inode * inode);
extern void iget_failed(struct inode *);
extern void clear_inode(struct inode *);
extern void __destroy_inode(struct inode *);
extern struct inode *new_inode_pseudo(struct super_block *sb);
extern struct inode *new_inode(struct super_block *sb);
extern void free_inode_nonrcu(struct inode *inode);
extern int should_remove_suid(struct dentry *);
extern int file_remove_privs(struct file *);
extern void __insert_inode_hash(struct inode *, unsigned long hashval);
static inline void insert_inode_hash(struct inode *inode)
{
__insert_inode_hash(inode, inode->i_ino);
}
extern void __remove_inode_hash(struct inode *);
static inline void remove_inode_hash(struct inode *inode)
{
if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))
__remove_inode_hash(inode);
}
extern void inode_sb_list_add(struct inode *inode);
#ifdef CONFIG_BLOCK
extern blk_qc_t submit_bio(struct bio *);
extern int bdev_read_only(struct block_device *);
#endif
extern int set_blocksize(struct block_device *, int);
extern int sb_set_blocksize(struct super_block *, int);
extern int sb_min_blocksize(struct super_block *, int);
extern int generic_file_mmap(struct file *, struct vm_area_struct *);
extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *);
extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos);
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos);
/* fs/block_dev.c */
extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);
extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from);
extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
int datasync);
extern void block_sync_page(struct page *page);
/* fs/splice.c */
extern ssize_t generic_file_splice_read(struct file *, loff_t *,
struct pipe_inode_info *, size_t, unsigned int);
extern ssize_t iter_file_splice_write(struct pipe_inode_info *,
struct file *, loff_t *, size_t, unsigned int);
extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
struct file *out, loff_t *, size_t len, unsigned int flags);
extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
loff_t *opos, size_t len, unsigned int flags);
extern void
file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
extern loff_t noop_llseek(struct file *file, loff_t offset, int whence);
extern loff_t no_llseek(struct file *file, loff_t offset, int whence);
extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize);
extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence);
extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,
int whence, loff_t maxsize, loff_t eof);
extern loff_t fixed_size_llseek(struct file *file, loff_t offset,
int whence, loff_t size);
extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t);
extern loff_t no_seek_end_llseek(struct file *, loff_t, int);
extern int generic_file_open(struct inode * inode, struct file * filp);
extern int nonseekable_open(struct inode * inode, struct file * filp);
#ifdef CONFIG_BLOCK
typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,
loff_t file_offset);
enum {
/* need locking between buffered and direct access */
DIO_LOCKING = 0x01,
/* filesystem does not support filling holes */
DIO_SKIP_HOLES = 0x02,
/* filesystem can handle aio writes beyond i_size */
DIO_ASYNC_EXTEND = 0x04,
/* inode/fs/bdev does not need truncate protection */
DIO_SKIP_DIO_COUNT = 0x08,
};
void dio_end_io(struct bio *bio, int error);
ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,
struct block_device *bdev, struct iov_iter *iter,
get_block_t get_block,
dio_iodone_t end_io, dio_submit_t submit_io,
int flags);
static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
struct inode *inode,
struct iov_iter *iter,
get_block_t get_block)
{
return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES);
}
#endif
void inode_dio_wait(struct inode *inode);
/*
* inode_dio_begin - signal start of a direct I/O requests
* @inode: inode the direct I/O happens on
*
* This is called once we've finished processing a direct I/O request,
* and is used to wake up callers waiting for direct I/O to be quiesced.
*/
static inline void inode_dio_begin(struct inode *inode)
{
atomic_inc(&inode->i_dio_count);
}
/*
* inode_dio_end - signal finish of a direct I/O requests
* @inode: inode the direct I/O happens on
*
* This is called once we've finished processing a direct I/O request,
* and is used to wake up callers waiting for direct I/O to be quiesced.
*/
static inline void inode_dio_end(struct inode *inode)
{
if (atomic_dec_and_test(&inode->i_dio_count))
wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
}
extern void inode_set_flags(struct inode *inode, unsigned int flags,
unsigned int mask);
extern const struct file_operations generic_ro_fops;
#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
extern int readlink_copy(char __user *, int, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
extern const char *page_get_link(struct dentry *, struct inode *,
struct delayed_call *);
extern void page_put_link(void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
int nofs);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
extern void kfree_link(void *);
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
extern int vfs_getattr(struct path *, struct kstat *);
void __inode_add_bytes(struct inode *inode, loff_t bytes);
void inode_add_bytes(struct inode *inode, loff_t bytes);
void __inode_sub_bytes(struct inode *inode, loff_t bytes);
void inode_sub_bytes(struct inode *inode, loff_t bytes);
loff_t inode_get_bytes(struct inode *inode);
void inode_set_bytes(struct inode *inode, loff_t bytes);
const char *simple_get_link(struct dentry *, struct inode *,
struct delayed_call *);
extern const struct inode_operations simple_symlink_inode_operations;
extern int iterate_dir(struct file *, struct dir_context *);
extern int vfs_stat(const char __user *, struct kstat *);
extern int vfs_lstat(const char __user *, struct kstat *);
extern int vfs_fstat(unsigned int, struct kstat *);
extern int vfs_fstatat(int , const char __user *, struct kstat *, int);
extern const char *vfs_get_link(struct dentry *, struct delayed_call *);
extern int __generic_block_fiemap(struct inode *inode,
struct fiemap_extent_info *fieinfo,
loff_t start, loff_t len,
get_block_t *get_block);
extern int generic_block_fiemap(struct inode *inode,
struct fiemap_extent_info *fieinfo, u64 start,
u64 len, get_block_t *get_block);
extern void get_filesystem(struct file_system_type *fs);
extern void put_filesystem(struct file_system_type *fs);
extern struct file_system_type *get_fs_type(const char *name);
extern struct super_block *get_super(struct block_device *);
extern struct super_block *get_super_thawed(struct block_device *);
extern struct super_block *get_active_super(struct block_device *bdev);
extern void drop_super(struct super_block *sb);
extern void iterate_supers(void (*)(struct super_block *, void *), void *);
extern void iterate_supers_type(struct file_system_type *,
void (*)(struct super_block *, void *), void *);
extern int dcache_dir_open(struct inode *, struct file *);
extern int dcache_dir_close(struct inode *, struct file *);
extern loff_t dcache_dir_lseek(struct file *, loff_t, int);
extern int dcache_readdir(struct file *, struct dir_context *);
extern int simple_setattr(struct dentry *, struct iattr *);
extern int simple_getattr(struct vfsmount *, struct dentry *, struct kstat *);
extern int simple_statfs(struct dentry *, struct kstatfs *);
extern int simple_open(struct inode *inode, struct file *file);
extern int simple_link(struct dentry *, struct inode *, struct dentry *);
extern int simple_unlink(struct inode *, struct dentry *);
extern int simple_rmdir(struct inode *, struct dentry *);
extern int simple_rename(struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
extern int noop_fsync(struct file *, loff_t, loff_t, int);
extern int simple_empty(struct dentry *);
extern int simple_readpage(struct file *file, struct page *page);
extern int simple_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata);
extern int simple_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata);
extern int always_delete_dentry(const struct dentry *);
extern struct inode *alloc_anon_inode(struct super_block *);
extern int simple_nosetlease(struct file *, long, struct file_lock **, void **);
extern const struct dentry_operations simple_dentry_operations;
extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags);
extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *);
extern const struct file_operations simple_dir_operations;
extern const struct inode_operations simple_dir_inode_operations;
extern void make_empty_dir_inode(struct inode *inode);
extern bool is_empty_dir_inode(struct inode *inode);
struct tree_descr { char *name; const struct file_operations *ops; int mode; };
struct dentry *d_alloc_name(struct dentry *, const char *);
extern int simple_fill_super(struct super_block *, unsigned long, struct tree_descr *);
extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count);
extern void simple_release_fs(struct vfsmount **mount, int *count);
extern ssize_t simple_read_from_buffer(void __user *to, size_t count,
loff_t *ppos, const void *from, size_t available);
extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,
const void __user *from, size_t count);
extern int __generic_file_fsync(struct file *, loff_t, loff_t, int);
extern int generic_file_fsync(struct file *, loff_t, loff_t, int);
extern int generic_check_addressable(unsigned, u64);
#ifdef CONFIG_MIGRATION
extern int buffer_migrate_page(struct address_space *,
struct page *, struct page *,
enum migrate_mode);
#else
#define buffer_migrate_page NULL
#endif
extern int setattr_prepare(struct dentry *, struct iattr *);
extern int inode_newsize_ok(const struct inode *, loff_t offset);
extern void setattr_copy(struct inode *inode, const struct iattr *attr);
extern int file_update_time(struct file *file);
extern int generic_show_options(struct seq_file *m, struct dentry *root);
extern void save_mount_options(struct super_block *sb, char *options);
extern void replace_mount_options(struct super_block *sb, char *options);
static inline bool io_is_direct(struct file *filp)
{
return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host);
}
static inline int iocb_flags(struct file *file)
{
int res = 0;
if (file->f_flags & O_APPEND)
res |= IOCB_APPEND;
if (io_is_direct(file))
res |= IOCB_DIRECT;
if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
res |= IOCB_DSYNC;
if (file->f_flags & __O_SYNC)
res |= IOCB_SYNC;
return res;
}
static inline ino_t parent_ino(struct dentry *dentry)
{
ino_t res;
/*
* Don't strictly need d_lock here? If the parent ino could change
* then surely we'd have a deeper race in the caller?
*/
spin_lock(&dentry->d_lock);
res = dentry->d_parent->d_inode->i_ino;
spin_unlock(&dentry->d_lock);
return res;
}
/* Transaction based IO helpers */
/*
* An argresp is stored in an allocated page and holds the
* size of the argument or response, along with its content
*/
struct simple_transaction_argresp {
ssize_t size;
char data[0];
};
#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))
char *simple_transaction_get(struct file *file, const char __user *buf,
size_t size);
ssize_t simple_transaction_read(struct file *file, char __user *buf,
size_t size, loff_t *pos);
int simple_transaction_release(struct inode *inode, struct file *file);
void simple_transaction_set(struct file *file, size_t n);
/*
* simple attribute files
*
* These attributes behave similar to those in sysfs:
*
* Writing to an attribute immediately sets a value, an open file can be
* written to multiple times.
*
* Reading from an attribute creates a buffer from the value that might get
* read with multiple read calls. When the attribute has been read
* completely, no further read calls are possible until the file is opened
* again.
*
* All attributes contain a text representation of a numeric value
* that are accessed with the get() and set() functions.
*/
#define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \
static int __fops ## _open(struct inode *inode, struct file *file) \
{ \
__simple_attr_check_format(__fmt, 0ull); \
return simple_attr_open(inode, file, __get, __set, __fmt); \
} \
static const struct file_operations __fops = { \
.owner = THIS_MODULE, \
.open = __fops ## _open, \
.release = simple_attr_release, \
.read = simple_attr_read, \
.write = simple_attr_write, \
.llseek = generic_file_llseek, \
}
static inline __printf(1, 2)
void __simple_attr_check_format(const char *fmt, ...)
{
/* don't do anything, just let the compiler check the arguments; */
}
int simple_attr_open(struct inode *inode, struct file *file,
int (*get)(void *, u64 *), int (*set)(void *, u64),
const char *fmt);
int simple_attr_release(struct inode *inode, struct file *file);
ssize_t simple_attr_read(struct file *file, char __user *buf,
size_t len, loff_t *ppos);
ssize_t simple_attr_write(struct file *file, const char __user *buf,
size_t len, loff_t *ppos);
struct ctl_table;
int proc_nr_files(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
int proc_nr_dentry(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
int proc_nr_inodes(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);
int __init get_filesystem_list(char *buf);
#define __FMODE_EXEC ((__force int) FMODE_EXEC)
#define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY)
#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE])
#define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
(flag & __FMODE_NONOTIFY)))
static inline bool is_sxid(umode_t mode)
{
return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
}
static inline int check_sticky(struct inode *dir, struct inode *inode)
{
if (!(dir->i_mode & S_ISVTX))
return 0;
return __check_sticky(dir, inode);
}
static inline void inode_has_no_xattr(struct inode *inode)
{
if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & MS_NOSEC))
inode->i_flags |= S_NOSEC;
}
static inline bool is_root_inode(struct inode *inode)
{
return inode == inode->i_sb->s_root->d_inode;
}
static inline bool dir_emit(struct dir_context *ctx,
const char *name, int namelen,
u64 ino, unsigned type)
{
return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0;
}
static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx)
{
return ctx->actor(ctx, ".", 1, ctx->pos,
file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0;
}
static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx)
{
return ctx->actor(ctx, "..", 2, ctx->pos,
parent_ino(file->f_path.dentry), DT_DIR) == 0;
}
static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx)
{
if (ctx->pos == 0) {
if (!dir_emit_dot(file, ctx))
return false;
ctx->pos = 1;
}
if (ctx->pos == 1) {
if (!dir_emit_dotdot(file, ctx))
return false;
ctx->pos = 2;
}
return true;
}
static inline bool dir_relax(struct inode *inode)
{
inode_unlock(inode);
inode_lock(inode);
return !IS_DEADDIR(inode);
}
static inline bool dir_relax_shared(struct inode *inode)
{
inode_unlock_shared(inode);
inode_lock_shared(inode);
return !IS_DEADDIR(inode);
}
extern bool path_noexec(const struct path *path);
extern void inode_nohighmem(struct inode *inode);
#endif /* _LINUX_FS_H */