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Diffstat (limited to 'kernel/include/linux/fs.h')
| -rw-r--r-- | kernel/include/linux/fs.h | 2992 |
1 files changed, 2992 insertions, 0 deletions
diff --git a/kernel/include/linux/fs.h b/kernel/include/linux/fs.h new file mode 100644 index 000000000..571aab91b --- /dev/null +++ b/kernel/include/linux/fs.h @@ -0,0 +1,2992 @@ +#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 <asm/byteorder.h> +#include <uapi/linux/fs.h> + +struct backing_dev_info; +struct export_operations; +struct hd_geometry; +struct iovec; +struct nameidata; +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 vm_fault; + +extern void __init inode_init(void); +extern void __init inode_init_early(void); +extern void __init files_init(unsigned long); + +extern struct files_stat_struct files_stat; +extern unsigned long get_max_files(void); +extern 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 void (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 types that we support. Some of + * them include behavioral modifiers that send information down to the + * block layer and IO scheduler. 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. + * READA Used for read-ahead operations. Lower priority, and the + * block layer could (in theory) choose to ignore this + * request if it runs into resource problems. + * 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_WRITE +#define RWA_MASK REQ_RAHEAD + +#define READ 0 +#define WRITE RW_MASK +#define READA RWA_MASK + +#define READ_SYNC (READ | REQ_SYNC) +#define WRITE_SYNC (WRITE | REQ_SYNC | REQ_NOIDLE) +#define WRITE_ODIRECT (WRITE | REQ_SYNC) +#define WRITE_FLUSH (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH) +#define WRITE_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA) +#define WRITE_FLUSH_FUA (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | 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) + +/* + * 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) + +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, loff_t offset); + /* + * 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); + 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 */ + unsigned long nrshadows; /* number of shadow entries */ + pgoff_t writeback_index;/* writeback starts here */ + const struct address_space_operations *a_ops; /* methods */ + unsigned long flags; /* error bits/gfp mask */ + spinlock_t private_lock; /* for use by the address_space */ + 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 */ + struct list_head bd_inodes; + 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 IOP_FASTPERM 0x0001 +#define IOP_LOOKUP 0x0002 +#define IOP_NOFOLLOW 0x0004 + +/* + * 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 mutex i_mutex; + + unsigned long dirtied_when; /* jiffies of first dirtying */ + unsigned long dirtied_time_when; + + struct hlist_node i_hash; + struct list_head i_wb_list; /* backing dev IO list */ + struct list_head i_lru; /* inode LRU list */ + struct list_head i_sb_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; + }; + + __u32 i_generation; + +#ifdef CONFIG_FSNOTIFY + __u32 i_fsnotify_mask; /* all events this inode cares about */ + struct hlist_head i_fsnotify_marks; +#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, +}; + +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 +} + +/* 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(&init_user_ns, inode->i_uid); +} + +static inline gid_t i_gid_read(const struct inode *inode) +{ + return from_kgid(&init_user_ns, inode->i_gid); +} + +static inline void i_uid_write(struct inode *inode, uid_t uid) +{ + inode->i_uid = make_kuid(&init_user_ns, uid); +} + +static inline void i_gid_write(struct inode *inode, gid_t gid) +{ + inode->i_gid = make_kgid(&init_user_ns, gid); +} + +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_CACHE_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; +}; + +struct net; +void locks_start_grace(struct net *, struct lock_manager *); +void locks_end_grace(struct lock_manager *); +int locks_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); + +#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 file_lock_context *ctx); +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_lock_file_wait(struct file *, 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 flock_lock_file_wait(struct file *filp, 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 file_lock_context *ctx) +{ +} + +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_lock_file_wait(struct file *filp, struct file_lock *fl) +{ + 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 flock_lock_file_wait(struct file *filp, + struct file_lock *request) +{ + 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 */ + + +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 */ + + +/* 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 { + /* Counters for counting writers at each level */ + struct percpu_counter counter[SB_FREEZE_LEVELS]; + wait_queue_head_t wait; /* queue for waiting for + writers / faults to finish */ + int frozen; /* Is sb frozen? */ + wait_queue_head_t wait_unfrozen; /* queue for waiting for + sb to be thawed */ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map lock_map[SB_FREEZE_LEVELS]; +#endif +}; + +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_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; + + struct list_head s_inodes; /* all inodes */ + 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; + + /* + * 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; + + /* + * Indicates how deep in a filesystem stack this SB is + */ + int s_stack_depth; +}; + +extern struct timespec current_fs_time(struct super_block *sb); + +/* + * Snapshotting support. + */ + +void __sb_end_write(struct super_block *sb, int level); +int __sb_start_write(struct super_block *sb, int level, bool wait); + +/** + * 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 dentry helper functions. + */ +extern void dentry_unhash(struct dentry *dentry); + +/* + * VFS file helper functions. + */ +extern void inode_init_owner(struct inode *inode, const struct inode *dir, + umode_t mode); +/* + * 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 *); + 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 (*mremap)(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 (*aio_fsync) (struct kiocb *, 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 +}; + +struct inode_operations { + struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); + void * (*follow_link) (struct dentry *, struct nameidata *); + int (*permission) (struct inode *, int); + struct posix_acl * (*get_acl)(struct inode *, int); + + int (*readlink) (struct dentry *, char __user *,int); + void (*put_link) (struct dentry *, struct nameidata *, void *); + + 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 *); + int (*rename2) (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 *); + int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); + ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t); + ssize_t (*listxattr) (struct dentry *, char *, size_t); + int (*removexattr) (struct dentry *, const char *); + 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); + + /* WARNING: probably going away soon, do not use! */ + int (*dentry_open)(struct dentry *, struct file *, const struct cred *); +} ____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 *); +extern ssize_t vfs_writev(struct file *, const struct iovec __user *, + unsigned long, loff_t *); + +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) + +/* + * 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(). + * + * 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_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_USERNS_DEV_MOUNT 16 /* A userns mount does not imply MNT_NODEV */ +#define FS_USERNS_VISIBLE 32 /* FS must already be visible */ +#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, 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(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(struct file_system_type *, char *, + const struct super_operations *ops, + const struct dentry_operations *dops, + unsigned long); + +/* 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(struct path *); +extern void drop_collected_mounts(struct vfsmount *); +extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *, + struct vfsmount *); +extern int vfs_statfs(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); + +static inline struct inode *file_inode(const struct file *f) +{ + return f->f_inode; +} + +/* /sys/fs */ +extern struct kobject *fs_kobj; + +#define MAX_RW_COUNT (INT_MAX & PAGE_CACHE_MASK) + +#define FLOCK_VERIFY_READ 1 +#define FLOCK_VERIFY_WRITE 2 + +#ifdef CONFIG_FILE_LOCKING +extern int locks_mandatory_locked(struct file *); +extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size_t); + +/* + * 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(file_inode(file))) + return locks_mandatory_locked(file); + return 0; +} + +static inline int locks_verify_truncate(struct inode *inode, + struct file *filp, + loff_t size) +{ + if (inode->i_flctx && mandatory_lock(inode)) + return locks_mandatory_area( + FLOCK_VERIFY_WRITE, inode, filp, + size < inode->i_size ? size : inode->i_size, + (size < inode->i_size ? inode->i_size - size + : size - inode->i_size) + ); + return 0; +} + +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 locks_mandatory_locked(struct file *file) +{ + return 0; +} + +static inline int locks_mandatory_area(int rw, struct inode *inode, + struct file *filp, loff_t offset, + size_t count) +{ + 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; +} + +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(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); +extern int vfs_open(const struct path *, struct file *, const struct cred *); +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(unsigned long); + +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 int sb_is_blkdev_sb(struct super_block *sb); +#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 int sb_is_blkdev_sb(struct super_block *sb) +{ + return 0; +} +#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); +#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 +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 int is_bad_inode(struct inode *); + +#ifdef CONFIG_BLOCK +/* + * return READ, READA, or WRITE + */ +#define bio_rw(bio) ((bio)->bi_rw & (RW_MASK | RWA_MASK)) + +/* + * return data direction, READ or WRITE + */ +#define bio_data_dir(bio) ((bio)->bi_rw & 1) + +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 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 vfs_fsync_range(struct file *file, loff_t start, loff_t end, + int datasync); +extern int vfs_fsync(struct file *file, int datasync); +static inline int generic_write_sync(struct file *file, loff_t pos, loff_t count) +{ + if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host)) + return 0; + return vfs_fsync_range(file, pos, pos + count - 1, + (file->f_flags & __O_SYNC) ? 0 : 1); +} +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); + +extern int kernel_read(struct file *, loff_t, char *, unsigned long); +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 int is_subdir(struct dentry *, struct dentry *); +extern int path_is_under(struct path *, struct path *); + +#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_suid(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)) + __remove_inode_hash(inode); +} + +extern void inode_sb_list_add(struct inode *inode); + +#ifdef CONFIG_BLOCK +extern void submit_bio(int, 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 *, loff_t); +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 default_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 int generic_file_open(struct inode * inode, struct file * filp); +extern int nonseekable_open(struct inode * inode, struct file * filp); + +ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t, + get_block_t, dio_iodone_t, int flags); +int dax_clear_blocks(struct inode *, sector_t block, long size); +int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t); +int dax_truncate_page(struct inode *, loff_t from, get_block_t); +int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t); +int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *); +#define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb) + +#ifdef CONFIG_BLOCK +typedef void (dio_submit_t)(int rw, 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, + loff_t offset, 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, loff_t offset, + get_block_t get_block) +{ + return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, + offset, 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 void *page_follow_link_light(struct dentry *, struct nameidata *); +extern void page_put_link(struct dentry *, struct nameidata *, 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_put_link(struct dentry *, struct nameidata *, 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); + +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 int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, + unsigned long arg); +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 *); +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 inode_change_ok(const struct inode *, 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(file_inode(filp)); +} + +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; + 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 int 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) +{ + mutex_unlock(&inode->i_mutex); + mutex_lock(&inode->i_mutex); + return !IS_DEADDIR(inode); +} + +#endif /* _LINUX_FS_H */ |