dentry_kill(): don't try to remove from shrink list

If the victim in on the shrink list, don't remove it from there.
If shrink_dentry_list() manages to remove it from the list before
we are done - fine, we'll just free it as usual.  If not - mark
it with new flag (DCACHE_MAY_FREE) and leave it there.

Eventually, shrink_dentry_list() will get to it, remove the sucker
from shrink list and call dentry_kill(dentry, 0).  Which is where
we'll deal with freeing.

Since now dentry_kill(dentry, 0) may happen after or during
dentry_kill(dentry, 1), we need to recognize that (by seeing
DCACHE_DENTRY_KILLED already set), unlock everything
and either free the sucker (in case DCACHE_MAY_FREE has been
set) or leave it for ongoing dentry_kill(dentry, 1) to deal with.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-05-01 10:30:00 -04:00
parent 01b6035190
commit 41edf278fc
2 changed files with 21 additions and 8 deletions

View file

@ -221,6 +221,8 @@ struct dentry_operations {
#define DCACHE_SYMLINK_TYPE 0x00300000 /* Symlink */
#define DCACHE_FILE_TYPE 0x00400000 /* Other file type */
#define DCACHE_MAY_FREE 0x00800000
extern seqlock_t rename_lock;
static inline int dname_external(const struct dentry *dentry)