kernel/linux.git/fs/cifs/dir.c, branch linux-6.0.y

cifs: improve symlink handling for smb2+

2022-12-31T12:25:35+00:00

[ Upstream commit 76894f3e2f71177747b8b4763fb180e800279585 ] When creating inode for symlink, the client used to send below requests to fill it in: * create+query_info+close (STATUS_STOPPED_ON_SYMLINK) * create(+reparse_flag)+query_info+close (set file attrs) * create+ioctl(get_reparse)+close (query reparse tag) and then for every access to the symlink dentry, the ->link() method would send another: * create+ioctl(get_reparse)+close (parse symlink) So, in order to improve: (i) Get rid of unnecessary roundtrips and then resolve symlinks as follows: * create+query_info+close (STATUS_STOPPED_ON_SYMLINK + parse symlink + get reparse tag) * create(+reparse_flag)+query_info+close (set file attrs) (ii) Set the resolved symlink target directly in inode->i_link and use simple_get_link() for ->link() to simply return it. Signed-off-by: Paulo Alcantara (SUSE) Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French Stable-dep-of: f7f291e14dde ("cifs: fix oops during encryption") Signed-off-by: Sasha Levin

cifs: Fix xid leak in cifs_create()

2022-10-29T08:08:33+00:00

[ Upstream commit fee0fb1f15054bb6a0ede452acb42da5bef4d587 ] If the cifs already shutdown, we should free the xid before return, otherwise, the xid will be leaked. Fixes: 087f757b0129 ("cifs: add shutdown support") Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Zhang Xiaoxu Signed-off-by: Steve French Signed-off-by: Sasha Levin

cifs: when insecure legacy is disabled shrink amount of SMB1 code

2022-08-05T16:24:03+00:00

Currently much of the smb1 code is built even when CONFIG_CIFS_ALLOW_INSECURE_LEGACY is disabled. Move cifssmb.c to only be compiled when insecure legacy is disabled, and move various SMB1/CIFS helper functions to that ifdef. Some functions that were not SMB1/CIFS specific needed to be moved out of cifssmb.c This shrinks cifs.ko by more than 10% which is good - but also will help with the eventual movement of the legacy code to a distinct module. Follow on patches can shrink the number of ifdefs by code restructuring where smb1 code is wedged in functions that should be calling dialect specific helper functions instead, and also by moving some functions from file.c/dir.c/inode.c into smb1 specific c files. Reviewed-by: Ronnie Sahlberg Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

cifs: Support fscache indexing rewrite

2022-01-19T17:21:08+00:00

Change the cifs filesystem to take account of the changes to fscache's indexing rewrite and reenable caching in cifs. The following changes have been made: (1) The fscache_netfs struct is no more, and there's no need to register the filesystem as a whole. (2) The session cookie is now an fscache_volume cookie, allocated with fscache_acquire_volume(). That takes three parameters: a string representing the "volume" in the index, a string naming the cache to use (or NULL) and a u64 that conveys coherency metadata for the volume. For cifs, I've made it render the volume name string as: "cifs,," where the sharename has '/' characters replaced with ';'. This probably needs rethinking a bit as the total name could exceed the maximum filename component length. Further, the coherency data is currently just set to 0. It needs something else doing with it - I wonder if it would suffice simply to sum the resource_id, vol_create_time and vol_serial_number or maybe hash them. (3) The fscache_cookie_def is no more and needed information is passed directly to fscache_acquire_cookie(). The cache no longer calls back into the filesystem, but rather metadata changes are indicated at other times. fscache_acquire_cookie() is passed the same keying and coherency information as before. (4) The functions to set/reset cookies are removed and fscache_use_cookie() and fscache_unuse_cookie() are used instead. fscache_use_cookie() is passed a flag to indicate if the cookie is opened for writing. fscache_unuse_cookie() is passed updates for the metadata if we changed it (ie. if the file was opened for writing). These are called when the file is opened or closed. (5) cifs_setattr_*() are made to call fscache_resize() to change the size of the cache object. (6) The functions to read and write data are stubbed out pending a conversion to use netfslib. Changes ======= ver #8: - Abstract cache invalidation into a helper function. - Fix some checkpatch warnings[3]. ver #7: - Removed the accidentally added-back call to get the super cookie in cifs_root_iget(). - Fixed the right call to cifs_fscache_get_super_cookie() to take account of the "-o fsc" mount flag. ver #6: - Moved the change of gfpflags_allow_blocking() to current_is_kswapd() for cifs here. - Fixed one of the error paths in cifs_atomic_open() to jump around the call to use the cookie. - Fixed an additional successful return in the middle of cifs_open() to use the cookie on the way out. - Only get a volume cookie (and thus inode cookies) when "-o fsc" is supplied to mount. ver #5: - Fixed a couple of bits of cookie handling[2]: - The cookie should be released in cifs_evict_inode(), not cifsFileInfo_put_final(). The cookie needs to persist beyond file closure so that writepages will be able to write to it. - fscache_use_cookie() needs to be called in cifs_atomic_open() as it is for cifs_open(). ver #4: - Fixed the use of sizeof with memset. - tcon->vol_create_time is __le64 so doesn't need cpu_to_le64(). ver #3: - Canonicalise the cifs coherency data to make the cache portable. - Set volume coherency data. ver #2: - Use gfpflags_allow_blocking() rather than using flag directly. - Upgraded to -rc4 to allow for upstream changes[1]. - fscache_acquire_volume() now returns errors. Signed-off-by: David Howells Acked-by: Jeff Layton cc: Steve French cc: Shyam Prasad N cc: linux-cifs@vger.kernel.org cc: linux-cachefs@redhat.com Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=23b55d673d7527b093cd97b7c217c82e70cd1af0 [1] Link: https://lore.kernel.org/r/3419813.1641592362@warthog.procyon.org.uk/ [2] Link: https://lore.kernel.org/r/CAH2r5muTanw9pJqzAHd01d9A8keeChkzGsCEH6=0rHutVLAF-A@mail.gmail.com/ [3] Link: https://lore.kernel.org/r/163819671009.215744.11230627184193298714.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906982979.143852.10672081929614953210.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967187187.1823006.247415138444991444.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021579335.640689.2681324337038770579.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/3462849.1641593783@warthog.procyon.org.uk/ # v5 Link: https://lore.kernel.org/r/1318953.1642024578@warthog.procyon.org.uk/ # v6 Signed-off-by: Steve French

cifs: remove pathname for file from SPDX header

2021-09-13T19:51:10+00:00

checkpatch complains about source files with filenames (e.g. in these cases just below the SPDX header in comments at the top of various files in fs/cifs). It also is helpful to change this now so will be less confusing when the parent directory is renamed e.g. from fs/cifs to fs/smb_client (or fs/smbfs) Reviewed-by: Ronnie Sahlberg Signed-off-by: Steve French

cifs: use the correct max-length for dentry_path_raw()

2021-08-10T15:45:50+00:00

RHBZ: 1972502 PATH_MAX is 4096 but PAGE_SIZE can be >4096 on some architectures such as ppc and would thus write beyond the end of the actual object. Cc: Reported-by: Xiaoli Feng Suggested-by: Brian foster Reviewed-by: Paulo Alcantara (SUSE) Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French

cifs: missing null check for newinode pointer

2021-06-24T00:24:30+00:00

in cifs_do_create we check if newinode is valid before referencing it but are missing the check in one place in fs/cifs/dir.c Addresses-Coverity: 1357292 ("Dereference after null check") Acked-by: Sachin Prabhu Signed-off-by: Steve French

cifs: use SPDX-Licence-Identifier

2021-06-21T02:28:17+00:00

Add SPDX license identifier and replace license boilerplate. Corrects various checkpatch errors with the older format for noting the LGPL license. Signed-off-by: Steve French

cifs: retry lookup and readdir when EAGAIN is returned.

2021-06-21T02:28:17+00:00

According to the investigation performed by Jacob Shivers at Red Hat, cifs_lookup and cifs_readdir leak EAGAIN when the user session is deleted on the server. Fix this issue by implementing a retry with limits, as is implemented in cifs_revalidate_dentry_attr. Reproducer based on the work by Jacob Shivers: ~~~ $ cat readdir-cifs-test.sh #!/bin/bash # Install and configure powershell and sshd on the windows # server as descibed in # https://docs.microsoft.com/en-us/windows-server/administration/openssh/openssh_overview # This script uses expect(1) USER=dude SERVER=192.168.0.2 RPATH=root PASS='password' function debug_funcs { for line in $@ ; do echo "func $line +p" > /sys/kernel/debug/dynamic_debug/control done } function setup { echo 1 > /proc/fs/cifs/cifsFYI debug_funcs wait_for_compound_request \ smb2_query_dir_first cifs_readdir \ compound_send_recv cifs_reconnect_tcon \ generic_ip_connect cifs_reconnect \ smb2_reconnect_server smb2_reconnect \ cifs_readv_from_socket cifs_readv_receive tcpdump -i eth0 -w cifs.pcap host 192.168.2.182 & sleep 5 dmesg -C } function test_call { if [[ $1 == 1 ]] ; then tracer="strace -tt -f -s 4096 -o trace-$(date -Iseconds).txt" fi # Change the command here to anything appropriate $tracer ls $2 > /dev/null res=$? if [[ $1 == 1 ]] ; then if [[ $res == 0 ]] ; then 1>&2 echo success else 1>&2 echo "failure ($res)" fi fi } mountpoint /mnt > /dev/null || mount -t cifs -o username=$USER,pass=$PASS //$SERVER/$RPATH /mnt test_call 0 /mnt/ /usr/bin/expect << EOF set timeout 60 spawn ssh $USER@$SERVER expect "yes/no" { send "yes\r" expect "*?assword" { send "$PASS\r" } } "*?assword" { send "$PASS\r" } expect ">" { send "powershell close-smbsession -force\r" } expect ">" { send "exit\r" } expect eof EOF sysctl -w vm.drop_caches=2 > /dev/null sysctl -w vm.drop_caches=2 > /dev/null setup test_call 1 /mnt/ ~~~ Signed-off-by: Thiago Rafael Becker Acked-by: Ronnie Sahlberg Signed-off-by: Steve French

Merge tag '5.13-rc-smb3-part2' of git://git.samba.org/sfrench/cifs-2.6

2021-05-05T20:37:07+00:00

Pull cifs updates from Steve French: "Ten CIFS/SMB3 changes - including two marked for stable - including some important multichannel fixes, as well as support for handle leases (deferred close) and shutdown support: - some important multichannel fixes - support for handle leases (deferred close) - shutdown support (which is also helpful since it enables multiple xfstests) - enable negotiating stronger encryption by default (GCM256) - improve wireshark debugging by allowing more options for root to dump decryption keys SambaXP and the SMB3 Plugfest test event are going on now so I am expecting more patches over the next few days due to extra testing (including more multichannel fixes)" * tag '5.13-rc-smb3-part2' of git://git.samba.org/sfrench/cifs-2.6: fs/cifs: Fix resource leak Cifs: Fix kernel oops caused by deferred close for files. cifs: fix regression when mounting shares with prefix paths cifs: use echo_interval even when connection not ready. cifs: detect dead connections only when echoes are enabled. smb3.1.1: allow dumping keys for multiuser mounts smb3.1.1: allow dumping GCM256 keys to improve debugging of encrypted shares cifs: add shutdown support cifs: Deferred close for files smb3.1.1: enable negotiating stronger encryption by default