Unverified Commit b2b4483b authored by Omar Sandoval's avatar Omar Sandoval Committed by Christian Brauner
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dcache: convert dentry flag macros to enum 

Commit 9748cb2d ("VFS: repack DENTRY_ flags.") changed the value of
DCACHE_MOUNTED, which broke drgn's path_lookup() helper. drgn is forced
to hard-code it because it's a macro, and macros aren't preserved in
debugging information by default.

Enums, on the other hand, are included in debugging information. Convert
the DCACHE_* flag macros to an enum so that debugging tools like drgn
and bpftrace can make use of them.

Link: https://github.com/osandov/drgn/blob/2027d0fea84d74b835e77392f7040c2a333180c6/drgn/helpers/linux/fs.py#L43-L46


Signed-off-by: default avatarOmar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/177665a082f048cf536b9cd6af467b3be6b6e6ed.1744141838.git.osandov@fb.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent a64e4d48

include/linux/dcache.h

+50 −56
Original line number Diff line number Diff line
@@ -173,65 +173,59 @@ struct dentry_operations { 
 */



/* d_flags entries */

#define DCACHE_OP_HASH			BIT(0)

#define DCACHE_OP_COMPARE		BIT(1)

#define DCACHE_OP_REVALIDATE		BIT(2)

#define DCACHE_OP_DELETE		BIT(3)

#define DCACHE_OP_PRUNE			BIT(4)



#define	DCACHE_DISCONNECTED		BIT(5)

     /* This dentry is possibly not currently connected to the dcache tree, in

      * which case its parent will either be itself, or will have this flag as

      * well.  nfsd will not use a dentry with this bit set, but will first

      * endeavour to clear the bit either by discovering that it is connected,

      * or by performing lookup operations.   Any filesystem which supports

      * nfsd_operations MUST have a lookup function which, if it finds a

      * directory inode with a DCACHE_DISCONNECTED dentry, will d_move that

      * dentry into place and return that dentry rather than the passed one,

      * typically using d_splice_alias. */



#define DCACHE_REFERENCED		BIT(6) /* Recently used, don't discard. */



#define DCACHE_DONTCACHE		BIT(7) /* Purge from memory on final dput() */



#define DCACHE_CANT_MOUNT		BIT(8)

#define DCACHE_GENOCIDE			BIT(9)

#define DCACHE_SHRINK_LIST		BIT(10)



#define DCACHE_OP_WEAK_REVALIDATE	BIT(11)



#define DCACHE_NFSFS_RENAMED		BIT(12)

     /* this dentry has been "silly renamed" and has to be deleted on the last

      * dput() */

#define DCACHE_FSNOTIFY_PARENT_WATCHED	BIT(13)

     /* Parent inode is watched by some fsnotify listener */



#define DCACHE_DENTRY_KILLED		BIT(14)



#define DCACHE_MOUNTED			BIT(15) /* is a mountpoint */

#define DCACHE_NEED_AUTOMOUNT		BIT(16) /* handle automount on this dir */

#define DCACHE_MANAGE_TRANSIT		BIT(17) /* manage transit from this dirent */

enum dentry_flags {

	DCACHE_OP_HASH			= BIT(0),

	DCACHE_OP_COMPARE		= BIT(1),

	DCACHE_OP_REVALIDATE		= BIT(2),

	DCACHE_OP_DELETE		= BIT(3),

	DCACHE_OP_PRUNE			= BIT(4),

	/*

	 * This dentry is possibly not currently connected to the dcache tree,

	 * in which case its parent will either be itself, or will have this

	 * flag as well.  nfsd will not use a dentry with this bit set, but will

	 * first endeavour to clear the bit either by discovering that it is

	 * connected, or by performing lookup operations.  Any filesystem which

	 * supports nfsd_operations MUST have a lookup function which, if it

	 * finds a directory inode with a DCACHE_DISCONNECTED dentry, will

	 * d_move that dentry into place and return that dentry rather than the

	 * passed one, typically using d_splice_alias.

	 */

	DCACHE_DISCONNECTED		= BIT(5),

	DCACHE_REFERENCED		= BIT(6),	/* Recently used, don't discard. */

	DCACHE_DONTCACHE		= BIT(7),	/* Purge from memory on final dput() */

	DCACHE_CANT_MOUNT		= BIT(8),

	DCACHE_GENOCIDE			= BIT(9),

	DCACHE_SHRINK_LIST		= BIT(10),

	DCACHE_OP_WEAK_REVALIDATE	= BIT(11),

	/*

	 * this dentry has been "silly renamed" and has to be deleted on the

	 * last dput()

	 */

	DCACHE_NFSFS_RENAMED		= BIT(12),

	DCACHE_FSNOTIFY_PARENT_WATCHED	= BIT(13),	/* Parent inode is watched by some fsnotify listener */

	DCACHE_DENTRY_KILLED		= BIT(14),

	DCACHE_MOUNTED			= BIT(15),	/* is a mountpoint */

	DCACHE_NEED_AUTOMOUNT		= BIT(16),	/* handle automount on this dir */

	DCACHE_MANAGE_TRANSIT		= BIT(17),	/* manage transit from this dirent */

	DCACHE_LRU_LIST			= BIT(18),

	DCACHE_ENTRY_TYPE		= (7 << 19),	/* bits 19..21 are for storing type: */

	DCACHE_MISS_TYPE		= (0 << 19),	/* Negative dentry */

	DCACHE_WHITEOUT_TYPE		= (1 << 19),	/* Whiteout dentry (stop pathwalk) */

	DCACHE_DIRECTORY_TYPE		= (2 << 19),	/* Normal directory */

	DCACHE_AUTODIR_TYPE		= (3 << 19),	/* Lookupless directory (presumed automount) */

	DCACHE_REGULAR_TYPE		= (4 << 19),	/* Regular file type */

	DCACHE_SPECIAL_TYPE		= (5 << 19),	/* Other file type */

	DCACHE_SYMLINK_TYPE		= (6 << 19),	/* Symlink */

	DCACHE_NOKEY_NAME		= BIT(22),	/* Encrypted name encoded without key */

	DCACHE_OP_REAL			= BIT(23),

	DCACHE_PAR_LOOKUP		= BIT(24),	/* being looked up (with parent locked shared) */

	DCACHE_DENTRY_CURSOR		= BIT(25),

	DCACHE_NORCU			= BIT(26),	/* No RCU delay for freeing */

};



#define DCACHE_MANAGED_DENTRY \

	(DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)



#define DCACHE_LRU_LIST			BIT(18)



#define DCACHE_ENTRY_TYPE		(7 << 19) /* bits 19..21 are for storing type: */

#define DCACHE_MISS_TYPE		(0 << 19) /* Negative dentry */

#define DCACHE_WHITEOUT_TYPE		(1 << 19) /* Whiteout dentry (stop pathwalk) */

#define DCACHE_DIRECTORY_TYPE		(2 << 19) /* Normal directory */

#define DCACHE_AUTODIR_TYPE		(3 << 19) /* Lookupless directory (presumed automount) */

#define DCACHE_REGULAR_TYPE		(4 << 19) /* Regular file type */

#define DCACHE_SPECIAL_TYPE		(5 << 19) /* Other file type */

#define DCACHE_SYMLINK_TYPE		(6 << 19) /* Symlink */



#define DCACHE_NOKEY_NAME		BIT(22) /* Encrypted name encoded without key */

#define DCACHE_OP_REAL			BIT(23)



#define DCACHE_PAR_LOOKUP		BIT(24) /* being looked up (with parent locked shared) */

#define DCACHE_DENTRY_CURSOR		BIT(25)

#define DCACHE_NORCU			BIT(26) /* No RCU delay for freeing */



extern seqlock_t rename_lock;



/*