fs/jfs/jfs_imap.h

Source file repositories/reference/linux-study-clean/fs/jfs/jfs_imap.h

File Facts

System
Linux kernel
Corpus path
fs/jfs/jfs_imap.h
Extension
.h
Size
5907 bytes
Lines
163
Domain
Core OS
Bucket
VFS And Filesystem Core
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

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

Dependency Surface

Detected Declarations

Annotated Snippet

struct iag {
	__le64 agstart;		/* 8: starting block of ag		*/
	__le32 iagnum;		/* 4: inode allocation group number	*/
	__le32 inofreefwd;	/* 4: ag inode free list forward	*/
	__le32 inofreeback;	/* 4: ag inode free list back		*/
	__le32 extfreefwd;	/* 4: ag inode extent free list forward	*/
	__le32 extfreeback;	/* 4: ag inode extent free list back	*/
	__le32 iagfree;		/* 4: iag free list			*/

	/* summary map: 1 bit per inode extent */
	__le32 inosmap[SMAPSZ];	/* 16: sum map of mapwords w/ free inodes;
				 *	note: this indicates free and backed
				 *	inodes, if the extent is not backed the
				 *	value will be 1.  if the extent is
				 *	backed but all inodes are being used the
				 *	value will be 1.  if the extent is
				 *	backed but at least one of the inodes is
				 *	free the value will be 0.
				 */
	__le32 extsmap[SMAPSZ];	/* 16: sum map of mapwords w/ free extents */
	__le32 nfreeinos;	/* 4: number of free inodes		*/
	__le32 nfreeexts;	/* 4: number of free extents		*/
	/* (72) */
	u8 pad[1976];		/* 1976: pad to 2048 bytes */
	/* allocation bit map: 1 bit per inode (0 - free, 1 - allocated) */
	__le32 wmap[EXTSPERIAG];	/* 512: working allocation map */
	__le32 pmap[EXTSPERIAG];	/* 512: persistent allocation map */
	pxd_t inoext[EXTSPERIAG];	/* 1024: inode extent addresses */
};				/* (4096) */

/*
 *	per AG control information (in inode map control page)
 */
struct iagctl_disk {
	__le32 inofree;		/* 4: free inode list anchor		*/
	__le32 extfree;		/* 4: free extent list anchor		*/
	__le32 numinos;		/* 4: number of backed inodes		*/
	__le32 numfree;		/* 4: number of free inodes		*/
};				/* (16) */

struct iagctl {
	int inofree;		/* free inode list anchor		*/
	int extfree;		/* free extent list anchor		*/
	int numinos;		/* number of backed inodes		*/
	int numfree;		/* number of free inodes		*/
};

/*
 *	per fileset/aggregate inode map control page
 */
struct dinomap_disk {
	__le32 in_freeiag;	/* 4: free iag list anchor	*/
	__le32 in_nextiag;	/* 4: next free iag number	*/
	__le32 in_numinos;	/* 4: num of backed inodes	*/
	__le32 in_numfree;	/* 4: num of free backed inodes */
	__le32 in_nbperiext;	/* 4: num of blocks per inode extent */
	__le32 in_l2nbperiext;	/* 4: l2 of in_nbperiext	*/
	__le32 in_diskblock;	/* 4: for standalone test driver */
	__le32 in_maxag;	/* 4: for standalone test driver */
	u8 pad[2016];		/* 2016: pad to 2048		*/
	struct iagctl_disk in_agctl[MAXAG]; /* 2048: AG control information */
};				/* (4096) */

struct dinomap {
	int in_freeiag;		/* free iag list anchor		*/
	int in_nextiag;		/* next free iag number		*/
	int in_numinos;		/* num of backed inodes		*/
	int in_numfree;		/* num of free backed inodes	*/
	int in_nbperiext;	/* num of blocks per inode extent */
	int in_l2nbperiext;	/* l2 of in_nbperiext		*/
	int in_diskblock;	/* for standalone test driver	*/
	int in_maxag;		/* for standalone test driver	*/
	struct iagctl in_agctl[MAXAG];	/* AG control information */
};

/*
 *	In-core inode map control page
 */
struct inomap {
	struct dinomap im_imap;		/* 4096: inode allocation control */
	struct inode *im_ipimap;	/* 4: ptr to inode for imap	*/
	struct mutex im_freelock;	/* 4: iag free list lock	*/
	struct mutex im_aglock[MAXAG];	/* 512: per AG locks		*/
	u32 *im_DBGdimap;
	atomic_t im_numinos;	/* num of backed inodes */
	atomic_t im_numfree;	/* num of free backed inodes */
};

#define	im_freeiag	im_imap.in_freeiag
#define	im_nextiag	im_imap.in_nextiag

Annotation

Implementation Notes