wireguard-linux/fs/cifs, branch jd/unified-crypt-queue

smb3: enable swap on SMB3 mounts

2020-04-10T18:32:32Z

Add experimental support for allowing a swap file to be on an SMB3 mount. There are use cases where swapping over a secure network filesystem is preferable. In some cases there are no local block devices large enough, and network block devices can be hard to setup and secure. And in some cases there are no local block devices at all (e.g. with the recent addition of remote boot over SMB3 mounts). There are various enhancements that can be added later e.g.: - doing a mandatory byte range lock over the swapfile (until the Linux VFS is modified to notify the file system that an open is for a swapfile, when the file can be opened "DENY_ALL" to prevent others from opening it). - pinning more buffers in the underlying transport to minimize memory allocations in the TCP stack under the fs - documenting how to create ACLs (on the server) to secure the swapfile (or adding additional tools to cifs-utils to make it easier) Signed-off-by: Steve French Acked-by: Pavel Shilovsky Reviewed-by: Ronnie Sahlberg

smb3: change noisy error message to FYI

2020-04-09T18:28:24Z

The noisy posix error message in readdir was supposed to be an FYI (not enabled by default) CIFS VFS: XXX dev 66306, reparse 0, mode 755 Signed-off-by: Steve French Reviewed-by: Aurelien Aptel

smb3: smbdirect support can be configured by default

2020-04-07T18:39:00Z

smbdirect support (SMB3 over RDMA) should be enabled by default in many configurations. It is not experimental and is stable enough and has enough performance benefits to recommend that it be configured by default. Change the "If unsure N" to "If unsure Y" in the description of the configuration parameter. Acked-by: Aurelien Aptel Reviewed-by: Long Li Signed-off-by: Steve French

cifs: smbd: Do not schedule work to send immediate packet on every receive

2020-04-07T17:41:16Z

Immediate packets should only be sent to peer when there are new receive credits made available. New credits show up on freeing receive buffer, not on receiving data. Fix this by avoid unnenecessary work schedules. Signed-off-by: Long Li Signed-off-by: Steve French

cifs: smbd: Properly process errors on ib_post_send

2020-04-07T17:41:16Z

When processing errors from ib_post_send(), the transport state needs to be rolled back to the condition before the error. Refactor the old code to make it easy to roll back on IB errors, and fix this. Signed-off-by: Long Li Signed-off-by: Steve French

cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets

2020-04-07T17:41:16Z

CIFS uses pre-allocated crypto structures to calculate signatures for both incoming and outgoing packets. In this way it doesn't need to allocate crypto structures for every packet, but it requires a lock to prevent concurrent access to crypto structures. Remove the lock by allocating crypto structures on the fly for incoming packets. At the same time, we can still use pre-allocated crypto structures for outgoing packets, as they are already protected by transport lock srv_mutex. Signed-off-by: Long Li Signed-off-by: Steve French

cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending

2020-04-07T17:41:16Z

Recevie credits should be updated before sending the packet, not before a work is scheduled. Also, the value needs roll back if something fails and cannot send. Signed-off-by: Long Li Reported-by: kbuild test robot Signed-off-by: Steve French

cifs: smbd: Check send queue size before posting a send

2020-04-07T17:41:16Z

Sometimes the remote peer may return more send credits than the send queue depth. If all the send credits are used to post senasd, we may overflow the send queue. Fix this by checking the send queue size before posting a send. Signed-off-by: Long Li Signed-off-by: Steve French

cifs: smbd: Merge code to track pending packets

2020-04-07T17:41:16Z

As an optimization, SMBD tries to track two types of packets: packets with payload and without payload. There is no obvious benefit or performance gain to separately track two types of packets. Just treat them as pending packets and merge the tracking code. Signed-off-by: Long Li Signed-off-by: Steve French

cifs: ignore cached share root handle closing errors

2020-04-07T17:40:40Z

Fix tcon use-after-free and NULL ptr deref. Customer system crashes with the following kernel log: [462233.169868] CIFS VFS: Cancelling wait for mid 4894753 cmd: 14 => a QUERY DIR [462233.228045] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4 [462233.305922] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4 [462233.306205] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4 [462233.347060] CIFS VFS: cifs_put_smb_ses: Session Logoff failure rc=-4 [462233.347107] CIFS VFS: Close unmatched open [462233.347113] BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 ... [exception RIP: cifs_put_tcon+0xa0] (this is doing tcon->ses->server) #6 [...] smb2_cancelled_close_fid at ... [cifs] #7 [...] process_one_work at ... #8 [...] worker_thread at ... #9 [...] kthread at ... The most likely explanation we have is: * When we put the last reference of a tcon (refcount=0), we close the cached share root handle. * If closing a handle is interrupted, SMB2_close() will queue a SMB2_close() in a work thread. * The queued object keeps a tcon ref so we bump the tcon refcount, jumping from 0 to 1. * We reach the end of cifs_put_tcon(), we free the tcon object despite it now having a refcount of 1. * The queued work now runs, but the tcon, ses & server was freed in the meantime resulting in a crash. THREAD 1 ======== cifs_put_tcon => tcon refcount reach 0 SMB2_tdis close_shroot_lease close_shroot_lease_locked => if cached root has lease && refcount = 0 smb2_close_cached_fid => if cached root valid SMB2_close => retry close in a thread if interrupted smb2_handle_cancelled_close __smb2_handle_cancelled_close => !! tcon refcount bump 0 => 1 !! INIT_WORK(&cancelled->work, smb2_cancelled_close_fid); queue_work(cifsiod_wq, &cancelled->work) => queue work tconInfoFree(tcon); ==> freed! cifs_put_smb_ses(ses); ==> freed! THREAD 2 (workqueue) ======== smb2_cancelled_close_fid SMB2_close(0, cancelled->tcon, ...); => use-after-free of tcon cifs_put_tcon(cancelled->tcon); => tcon refcount reach 0 second time *CRASH* Fixes: d9191319358d ("CIFS: Close cached root handle only if it has a lease") Signed-off-by: Aurelien Aptel Signed-off-by: Steve French Reviewed-by: Pavel Shilovsky