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| author | Al Viro <viro@zeniv.linux.org.uk> | 2015-05-28 23:09:19 -0400 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-08-07 00:32:13 +0100 |
| commit | 60593faea74ea54e84cb638f9cc59e32d8268f37 (patch) | |
| tree | 4e41dcc156c1d3b334df27459ea1ddfb26c1bcd8 /fs | |
| parent | a5045e0fee1a7b2cf132afb94977d4c8d781bd04 (diff) | |
| download | kernel_samsung_smdk4412-60593faea74ea54e84cb638f9cc59e32d8268f37.zip kernel_samsung_smdk4412-60593faea74ea54e84cb638f9cc59e32d8268f37.tar.gz kernel_samsung_smdk4412-60593faea74ea54e84cb638f9cc59e32d8268f37.tar.bz2 | |
d_walk() might skip too much
commit 2159184ea01e4ae7d15f2017e296d4bc82d5aeb0 upstream.
when we find that a child has died while we'd been trying to ascend,
we should go into the first live sibling itself, rather than its sibling.
Off-by-one in question had been introduced in "deal with deadlock in
d_walk()" and the fix needs to be backported to all branches this one
has been backported to.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.2: apply to the 3 copies of this logic we
ended up with]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/dcache.c | 24 |
1 files changed, 12 insertions, 12 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 8bc98af..8a35300 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1016,13 +1016,13 @@ ascend: /* might go back up the wrong parent if we have had a rename */ if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; - next = child->d_child.next; - while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)) { + /* go into the first sibling still alive */ + do { + next = child->d_child.next; if (next == &this_parent->d_subdirs) goto ascend; child = list_entry(next, struct dentry, d_child); - next = next->next; - } + } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)); rcu_read_unlock(); goto resume; } @@ -1142,13 +1142,13 @@ ascend: /* might go back up the wrong parent if we have had a rename */ if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; - next = child->d_child.next; - while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)) { + /* go into the first sibling still alive */ + do { + next = child->d_child.next; if (next == &this_parent->d_subdirs) goto ascend; child = list_entry(next, struct dentry, d_child); - next = next->next; - } + } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)); rcu_read_unlock(); goto resume; } @@ -2938,13 +2938,13 @@ ascend: /* might go back up the wrong parent if we have had a rename */ if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; - next = child->d_child.next; - while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)) { + /* go into the first sibling still alive */ + do { + next = child->d_child.next; if (next == &this_parent->d_subdirs) goto ascend; child = list_entry(next, struct dentry, d_child); - next = next->next; - } + } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)); rcu_read_unlock(); goto resume; } |