diff options
Diffstat (limited to 'fs/afs/dir.c')
-rw-r--r-- | fs/afs/dir.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 27c5231e89e7..3ebd741b74d0 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -767,6 +767,62 @@ out: } /* + * Look up an entry in a directory with @sys substitution. + */ +static struct dentry *afs_lookup_atsys(struct inode *dir, struct dentry *dentry, + struct key *key) +{ + struct afs_sysnames *subs; + struct afs_net *net = afs_i2net(dir); + struct dentry *ret; + char *buf, *p, *name; + int len, i; + + _enter(""); + + ret = ERR_PTR(-ENOMEM); + p = buf = kmalloc(AFSNAMEMAX, GFP_KERNEL); + if (!buf) + goto out_p; + if (dentry->d_name.len > 4) { + memcpy(p, dentry->d_name.name, dentry->d_name.len - 4); + p += dentry->d_name.len - 4; + } + + /* There is an ordered list of substitutes that we have to try. */ + read_lock(&net->sysnames_lock); + subs = net->sysnames; + refcount_inc(&subs->usage); + read_unlock(&net->sysnames_lock); + + for (i = 0; i < subs->nr; i++) { + name = subs->subs[i]; + len = dentry->d_name.len - 4 + strlen(name); + if (len >= AFSNAMEMAX) { + ret = ERR_PTR(-ENAMETOOLONG); + goto out_s; + } + + strcpy(p, name); + ret = lookup_one_len(buf, dentry->d_parent, len); + if (IS_ERR(ret) || d_is_positive(ret)) + goto out_s; + dput(ret); + } + + /* We don't want to d_add() the @sys dentry here as we don't want to + * the cached dentry to hide changes to the sysnames list. + */ + ret = NULL; +out_s: + afs_put_sysnames(subs); + kfree(buf); +out_p: + key_put(key); + return ret; +} + +/* * look up an entry in a directory */ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, @@ -805,6 +861,13 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, return ERR_PTR(ret); } + if (dentry->d_name.len >= 4 && + dentry->d_name.name[dentry->d_name.len - 4] == '@' && + dentry->d_name.name[dentry->d_name.len - 3] == 's' && + dentry->d_name.name[dentry->d_name.len - 2] == 'y' && + dentry->d_name.name[dentry->d_name.len - 1] == 's') + return afs_lookup_atsys(dir, dentry, key); + inode = afs_do_lookup(dir, dentry, key); if (IS_ERR(inode)) { ret = PTR_ERR(inode); |