fs/exfat/exfat_fs.h

File Facts

System

Linux kernel

Corpus path

fs/exfat/exfat_fs.h

Extension

.h

Size

22228 bytes

Lines

707

Domain

Core OS

Bucket

VFS And Filesystem Core

Inferred role

Core OS: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

• Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.
• Defines an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/fs.h
• linux/ratelimit.h
• linux/nls.h
• linux/blkdev.h
• linux/backing-dev.h
• uapi/linux/exfat.h
• linux/buffer_head.h

Detected Declarations

• struct exfat_dentry_namebuf
• struct exfat_uni_name
• struct exfat_chain
• struct exfat_hint_femp
• struct exfat_hint
• struct exfat_entry_set_cache
• struct exfat_dir_entry
• struct exfat_mount_options
• struct exfat_sb_info
• struct exfat_inode_info
• struct file_kattr
• enum exfat_error_mode
• function exfat_forced_shutdown
• function exfat_mode_can_hold_ro
• function exfat_make_mode
• function exfat_make_attr
• function exfat_save_attr
• function exfat_is_last_sector_in_cluster
• function exfat_cluster_to_sector
• function exfat_sector_to_cluster
• function is_valid_cluster
• function exfat_ondisk_size
• function exfat_cluster_to_phys_bytes
• function exfat_cluster_to_bytes
• function exfat_cluster_to_sectors
• function exfat_bytes_to_cluster
• function exfat_bytes_to_cluster_round_up
• function exfat_cluster_offset
• function exfat_block_to_bytes
• function exfat_bytes_to_block
• function exfat_bytes_to_block_round_up
• function exfat_block_offset
• function exfat_bytes_to_dentries
• function exfat_dentries_to_bytes
• function exfat_cluster_to_dentries
• function exfat_dentries_to_cluster
• function exfat_cluster_walk
• function exfat_chain_advance

Annotated Snippet

extern const struct file_operations exfat_file_operations;
int __exfat_truncate(struct inode *inode);
int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
		  struct iattr *attr);
int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
		  struct kstat *stat, unsigned int request_mask,
		  unsigned int query_flags);
struct file_kattr;
int exfat_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
long exfat_compat_ioctl(struct file *filp, unsigned int cmd,
				unsigned long arg);
int exfat_force_shutdown(struct super_block *sb, u32 flags);

/* namei.c */
extern const struct dentry_operations exfat_dentry_ops;
extern const struct dentry_operations exfat_utf8_dentry_ops;
int exfat_find_empty_entry(struct inode *inode,
		struct exfat_chain *p_dir, int num_entries,
			   struct exfat_entry_set_cache *es);

/* cache.c */
int exfat_cache_init(void);
void exfat_cache_shutdown(void);
void exfat_cache_inval_inode(struct inode *inode);
int exfat_get_cluster(struct inode *inode, unsigned int cluster,
		unsigned int *dclus, unsigned int *count, unsigned int *last_dclus);

/* dir.c */
extern const struct inode_operations exfat_dir_inode_operations;
extern const struct file_operations exfat_dir_operations;
unsigned int exfat_get_entry_type(struct exfat_dentry *p_entry);
void exfat_init_dir_entry(struct exfat_entry_set_cache *es,
		unsigned int type, unsigned int start_clu,
		unsigned long long size, struct timespec64 *ts);
void exfat_init_ext_entry(struct exfat_entry_set_cache *es, int num_entries,
		struct exfat_uni_name *p_uniname,
		struct exfat_entry_set_cache *old_es, int num_extra);
void exfat_remove_entries(struct inode *inode, struct exfat_entry_set_cache *es,
		int order, bool free_benign);
void exfat_update_dir_chksum(struct exfat_entry_set_cache *es);
int exfat_calc_num_entries(struct exfat_uni_name *p_uniname);
int exfat_find_dir_entry(struct super_block *sb, struct exfat_inode_info *ei,
		struct exfat_chain *p_dir, struct exfat_uni_name *p_uniname,
		struct exfat_hint *hint_opt);
int exfat_alloc_new_dir(struct inode *inode, struct exfat_chain *clu);
struct exfat_dentry *exfat_get_dentry(struct super_block *sb,
		struct exfat_chain *p_dir, int entry, struct buffer_head **bh);
struct exfat_dentry *exfat_get_dentry_cached(struct exfat_entry_set_cache *es,
		int num);
int exfat_get_dentry_set(struct exfat_entry_set_cache *es,
		struct super_block *sb, struct exfat_chain *p_dir, int entry,
		unsigned int num_entries);
#define exfat_get_dentry_set_by_ei(es, sb, ei)		\
	exfat_get_dentry_set(es, sb, &(ei)->dir, (ei)->entry, ES_ALL_ENTRIES)
int exfat_get_empty_dentry_set(struct exfat_entry_set_cache *es,
		struct super_block *sb, struct exfat_chain *p_dir, int entry,
		unsigned int num_entries);
int exfat_put_dentry_set(struct exfat_entry_set_cache *es, int sync);
int exfat_count_dir_entries(struct super_block *sb, struct exfat_chain *p_dir);
int exfat_read_volume_label(struct super_block *sb,
			    struct exfat_uni_name *label_out);
int exfat_write_volume_label(struct super_block *sb,
			     struct exfat_uni_name *label);

static inline int exfat_chain_advance(struct super_block *sb,
		struct exfat_chain *chain, unsigned int step)
{
	unsigned int clu = chain->dir;

	if (unlikely(chain->size < step))
		return -EIO;

	if (exfat_cluster_walk(sb, &clu, step, chain->flags))
		return -EIO;

	chain->size -= step;

	if (chain->size == 0 && chain->flags == ALLOC_NO_FAT_CHAIN)
		chain->dir = EXFAT_EOF_CLUSTER;
	else
		chain->dir = clu;

	return 0;
}

/* inode.c */
extern const struct inode_operations exfat_file_inode_operations;
void exfat_sync_inode(struct inode *inode);

Annotation

• Immediate include surface: `linux/fs.h`, `linux/ratelimit.h`, `linux/nls.h`, `linux/blkdev.h`, `linux/backing-dev.h`, `uapi/linux/exfat.h`, `linux/buffer_head.h`.
• Detected declarations: `struct exfat_dentry_namebuf`, `struct exfat_uni_name`, `struct exfat_chain`, `struct exfat_hint_femp`, `struct exfat_hint`, `struct exfat_entry_set_cache`, `struct exfat_dir_entry`, `struct exfat_mount_options`, `struct exfat_sb_info`, `struct exfat_inode_info`.
• Atlas domain: Core OS / VFS And Filesystem Core.
• Implementation status: pattern implementation candidate.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.