From 71f8b55bc30e82d6355e07811213d847981a32e2 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 11 Dec 2023 15:08:57 +0000 Subject: afs: Fix the dynamic root's d_delete to always delete unused dentries Fix the afs dynamic root's d_delete function to always delete unused dentries rather than only deleting them if they're positive. With things as they stand upstream, negative dentries stemming from failed DNS lookups stick around preventing retries. Fixes: 66c7e1d319a5 ("afs: Split the dynroot stuff out and give it its own ops tables") Signed-off-by: David Howells Tested-by: Markus Suvanto cc: Marc Dionne cc: linux-afs@lists.infradead.org --- fs/afs/dynroot.c | 13 +------------ 1 file changed, 1 insertion(+), 12 deletions(-) (limited to 'fs/afs/dynroot.c') diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index 1fa8cf23bd36..34474a061654 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -252,20 +252,9 @@ static int afs_dynroot_d_revalidate(struct dentry *dentry, unsigned int flags) return 1; } -/* - * Allow the VFS to enquire as to whether a dentry should be unhashed (mustn't - * sleep) - * - called from dput() when d_count is going to 0. - * - return 1 to request dentry be unhashed, 0 otherwise - */ -static int afs_dynroot_d_delete(const struct dentry *dentry) -{ - return d_really_is_positive(dentry); -} - const struct dentry_operations afs_dynroot_dentry_operations = { .d_revalidate = afs_dynroot_d_revalidate, - .d_delete = afs_dynroot_d_delete, + .d_delete = always_delete_dentry, .d_release = afs_d_release, .d_automount = afs_d_automount, }; -- cgit v1.2.3 From 74cef6872ceaefb5b6c5c60641371ea28702d358 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 11 Dec 2023 15:15:02 +0000 Subject: afs: Fix dynamic root lookup DNS check In the afs dynamic root directory, the ->lookup() function does a DNS check on the cell being asked for and if the DNS upcall reports an error it will report an error back to userspace (typically ENOENT). However, if a failed DNS upcall returns a new-style result, it will return a valid result, with the status field set appropriately to indicate the type of failure - and in that case, dns_query() doesn't return an error and we let stat() complete with no error - which can cause confusion in userspace as subsequent calls that trigger d_automount then fail with ENOENT. Fix this by checking the status result from a valid dns_query() and returning an error if it indicates a failure. Fixes: bbb4c4323a4d ("dns: Allow the dns resolver to retrieve a server set") Reported-by: Markus Suvanto Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216637 Signed-off-by: David Howells Tested-by: Markus Suvanto cc: Marc Dionne cc: linux-afs@lists.infradead.org --- fs/afs/dynroot.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'fs/afs/dynroot.c') diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index 34474a061654..1f656005018e 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -114,6 +114,7 @@ static int afs_probe_cell_name(struct dentry *dentry) struct afs_net *net = afs_d2net(dentry); const char *name = dentry->d_name.name; size_t len = dentry->d_name.len; + char *result = NULL; int ret; /* Names prefixed with a dot are R/W mounts. */ @@ -131,9 +132,22 @@ static int afs_probe_cell_name(struct dentry *dentry) } ret = dns_query(net->net, "afsdb", name, len, "srv=1", - NULL, NULL, false); - if (ret == -ENODATA || ret == -ENOKEY) + &result, NULL, false); + if (ret == -ENODATA || ret == -ENOKEY || ret == 0) ret = -ENOENT; + if (ret > 0 && ret >= sizeof(struct dns_server_list_v1_header)) { + struct dns_server_list_v1_header *v1 = (void *)result; + + if (v1->hdr.zero == 0 && + v1->hdr.content == DNS_PAYLOAD_IS_SERVER_LIST && + v1->hdr.version == 1 && + (v1->status != DNS_LOOKUP_GOOD && + v1->status != DNS_LOOKUP_GOOD_WITH_BAD)) + return -ENOENT; + + } + + kfree(result); return ret; } -- cgit v1.2.3