diff options
| -rw-r--r-- | fs/dcache.c | 56 |
1 files changed, 42 insertions, 14 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 0dbae053b664..bf6294a20f0e 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -973,10 +973,11 @@ int have_submounts(struct dentry *parent) struct dentry *this_parent; struct list_head *next; unsigned seq; + int locked = 0; -rename_retry: - this_parent = parent; seq = read_seqbegin(&rename_lock); +again: + this_parent = parent; if (d_mountpoint(parent)) goto positive; @@ -1021,7 +1022,7 @@ resume: /* might go back up the wrong parent if we have had a rename * or deletion */ if (this_parent != child->d_parent || - read_seqretry(&rename_lock, seq)) { + (!locked && read_seqretry(&rename_lock, seq))) { spin_unlock(&this_parent->d_lock); rcu_read_unlock(); goto rename_retry; @@ -1031,13 +1032,22 @@ resume: goto resume; } spin_unlock(&this_parent->d_lock); - if (read_seqretry(&rename_lock, seq)) + if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return 0; /* No mount points found in tree */ positive: - if (read_seqretry(&rename_lock, seq)) + if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return 1; + +rename_retry: + locked = 1; + write_seqlock(&rename_lock); + goto again; } EXPORT_SYMBOL(have_submounts); @@ -1061,11 +1071,11 @@ static int select_parent(struct dentry * parent) struct list_head *next; unsigned seq; int found = 0; + int locked = 0; -rename_retry: - this_parent = parent; seq = read_seqbegin(&rename_lock); - +again: + this_parent = parent; spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; @@ -1127,7 +1137,7 @@ resume: /* might go back up the wrong parent if we have had a rename * or deletion */ if (this_parent != child->d_parent || - read_seqretry(&rename_lock, seq)) { + (!locked && read_seqretry(&rename_lock, seq))) { spin_unlock(&this_parent->d_lock); rcu_read_unlock(); goto rename_retry; @@ -1138,9 +1148,18 @@ resume: } out: spin_unlock(&this_parent->d_lock); - if (read_seqretry(&rename_lock, seq)) + if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); return found; + +rename_retry: + if (found) + return found; + locked = 1; + write_seqlock(&rename_lock); + goto again; } /** @@ -2655,10 +2674,11 @@ void d_genocide(struct dentry *root) struct dentry *this_parent; struct list_head *next; unsigned seq; + int locked = 0; -rename_retry: - this_parent = root; seq = read_seqbegin(&rename_lock); +again: + this_parent = root; spin_lock(&this_parent->d_lock); repeat: next = this_parent->d_subdirs.next; @@ -2703,7 +2723,7 @@ resume: /* might go back up the wrong parent if we have had a rename * or deletion */ if (this_parent != child->d_parent || - read_seqretry(&rename_lock, seq)) { + (!locked && read_seqretry(&rename_lock, seq))) { spin_unlock(&this_parent->d_lock); rcu_read_unlock(); goto rename_retry; @@ -2713,8 +2733,16 @@ resume: goto resume; } spin_unlock(&this_parent->d_lock); - if (read_seqretry(&rename_lock, seq)) + if (!locked && read_seqretry(&rename_lock, seq)) goto rename_retry; + if (locked) + write_sequnlock(&rename_lock); + return; + +rename_retry: + locked = 1; + write_seqlock(&rename_lock); + goto again; } /** |