From: Omar Sandoval <osandov@xxxxxx>
Commit 9748cb2dc393 ("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: Omar Sandoval <osandov@xxxxxx>
---
Hi,
This is based on Linus' tree as of today. If possible, it'd be great to
get this in for 6.15.
Here are a couple of examples of similar changes in the past:
0b108e83795c ("SUNRPC: convert RPC_TASK_* constants to enum")
ff202303c398 ("mm: convert page type macros to enum")
There's also an alternative approach that is more verbose but allows for
automatic numbering:
enum dentry_flags {
__DCACHE_OP_HASH,
__DCACHE_OP_COMPARE,
...
};
#define DCACHE_OP_HASH BIT(__DCACHE_OP_HASH)
#define DCACHE_OP_COMPARE BIT(__DCACHE_OP_COMPARE)
...
Let me know if you'd prefer that approach.
Thanks,
Omar
include/linux/dcache.h | 105 ++++++++++++++++++++---------------------
1 file changed, 50 insertions(+), 55 deletions(-)
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 8d1395f945bf..a945cc86a8f1 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -173,65 +173,60 @@ 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)
+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),
+ /* Parent inode is watched by some fsnotify listener */
+ DCACHE_FSNOTIFY_PARENT_WATCHED = BIT(13),
+ 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_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 */
#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;
/*
--
2.49.0
