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author | Sage Weil <sage@newdream.net> | 2011-07-26 20:30:43 +0200 |
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committer | Sage Weil <sage@newdream.net> | 2011-07-26 20:30:43 +0200 |
commit | bf1c6aca96c9d2f117dc7e590c2bc2304e7febe1 (patch) | |
tree | 1ecb6f35e572ba1e498390d1b09faf3c309bbaee | |
parent | ceph: protect access to d_parent (diff) | |
download | linux-bf1c6aca96c9d2f117dc7e590c2bc2304e7febe1.tar.xz linux-bf1c6aca96c9d2f117dc7e590c2bc2304e7febe1.zip |
ceph: protect d_parent access in ceph_d_revalidate
Protect d_parent with d_lock. Carry a reference. Simplify the flow so
that there is a single exit point and cleanup.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
-rw-r--r-- | fs/ceph/dir.c | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index ed296ec121d1..31d27f8f8261 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -1024,36 +1024,38 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry) */ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd) { + int valid = 0; struct inode *dir; if (nd && nd->flags & LOOKUP_RCU) return -ECHILD; - dir = dentry->d_parent->d_inode; - dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode, ceph_dentry(dentry)->offset); + dir = ceph_get_dentry_parent_inode(dentry); + /* always trust cached snapped dentries, snapdir dentry */ if (ceph_snap(dir) != CEPH_NOSNAP) { dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); - goto out_touch; + valid = 1; + } else if (dentry->d_inode && + ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) { + valid = 1; + } else if (dentry_lease_is_valid(dentry) || + dir_lease_is_valid(dir, dentry)) { + valid = 1; } - if (dentry->d_inode && ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) - goto out_touch; - if (dentry_lease_is_valid(dentry) || - dir_lease_is_valid(dir, dentry)) - goto out_touch; - - dout("d_revalidate %p invalid\n", dentry); - d_drop(dentry); - return 0; -out_touch: - ceph_dentry_lru_touch(dentry); - return 1; + dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid"); + if (valid) + ceph_dentry_lru_touch(dentry); + else + d_drop(dentry); + iput(dir); + return valid; } /* |