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| author | Ian Kent <raven@themaw.net> | 2011-03-25 01:51:20 +0800 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-03-24 14:54:34 -0400 |
| commit | d4a85e35d1465da055264407d8395e84483084e6 (patch) | |
| tree | d3bdbf9edd438ecd1a6de1bc30b9c13b466559e5 /fs/autofs4 | |
| parent | f9398c233e3201874395eea8558eb616fb198648 (diff) | |
| download | linux-3.10-d4a85e35d1465da055264407d8395e84483084e6.tar.gz linux-3.10-d4a85e35d1465da055264407d8395e84483084e6.tar.bz2 linux-3.10-d4a85e35d1465da055264407d8395e84483084e6.zip | |
autofs4 - fix autofs4_expire_indirect() traversal
The vfs-scale changes changed the traversal used in
autofs4_expire_indirect() from a list to a depth first tree traversal
which isn't right.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/autofs4')
| -rw-r--r-- | fs/autofs4/expire.c | 52 |
1 files changed, 51 insertions, 1 deletions
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index c403abcc725..bc482e07b92 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -87,6 +87,56 @@ done: } /* + * Calculate and dget next entry in the subdirs list under root. + */ +static struct dentry *get_next_positive_subdir(struct dentry *prev, + struct dentry *root) +{ + struct list_head *next; + struct dentry *p, *q; + + spin_lock(&autofs4_lock); + + if (prev == NULL) { + spin_lock(&root->d_lock); + prev = dget_dlock(root); + next = prev->d_subdirs.next; + p = prev; + goto start; + } + + p = prev; + spin_lock(&p->d_lock); +again: + next = p->d_u.d_child.next; +start: + if (next == &root->d_subdirs) { + spin_unlock(&p->d_lock); + spin_unlock(&autofs4_lock); + dput(prev); + return NULL; + } + + q = list_entry(next, struct dentry, d_u.d_child); + + spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED); + /* Negative dentry - try next */ + if (!simple_positive(q)) { + spin_unlock(&p->d_lock); + p = q; + goto again; + } + dget_dlock(q); + spin_unlock(&q->d_lock); + spin_unlock(&p->d_lock); + spin_unlock(&autofs4_lock); + + dput(prev); + + return q; +} + +/* * Calculate and dget next entry in top down tree traversal. */ static struct dentry *get_next_positive_dentry(struct dentry *prev, @@ -333,7 +383,7 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, timeout = sbi->exp_timeout; dentry = NULL; - while ((dentry = get_next_positive_dentry(dentry, root))) { + while ((dentry = get_next_positive_subdir(dentry, root))) { spin_lock(&sbi->fs_lock); ino = autofs4_dentry_ino(dentry); /* No point expiring a pending mount */ |