SMB1 already supports querying reparse points and detecting types of
symlink, fifo, socket, block and char.
This change implements the missing part - ability to create a new reparse
points over SMB1. This includes everything which SMB2+ already supports:
- native SMB symlinks and sockets
- NFS style of special files (symlinks, fifos, sockets, char/block devs)
- WSL style of special files (symlinks, fifos, sockets, char/block devs)
Attaching a reparse point to an existing file or directory is done via
SMB1 SMB_COM_NT_TRANSACT/NT_TRANSACT_IOCTL/FSCTL_SET_REPARSE_POINT command
and implemented in a new cifs_create_reparse_inode() function.
This change introduce a new callback ->create_reparse_inode() which creates
a new reperse point file or directory and returns inode. For SMB1 it is
provided via that new cifs_create_reparse_inode() function.
Existing reparse.c code was only slightly updated to call new protocol
callback ->create_reparse_inode() instead of hardcoded SMB2+ function.
This make the whole reparse.c code to work with every SMB dialect.
The original callback ->create_reparse_symlink() is not needed anymore as
the implementation of new create_reparse_symlink() function is dialect
agnostic too. So the link.c code was updated to call that function directly
(and not via callback).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When not searching for child entries with msearch wildcard pattern then ask
server just for one output entry. There is no need to ask for more entries
as we are interested only for one search result, as we are doing query on
path.
CIFSFindFirst() with msearch=false is called by the cifs_query_path_info()
function.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
To query root path (without msearch wildcard) it is needed to
send pattern '\' instead of '' (empty string).
This allows to use CIFSFindFirst() to query information about root path
which is being used in followup changes.
This change fixes the stat() syscall called on the root path on the mount.
It is because stat() syscall uses the cifs_query_path_info() function and
it can fallback to the CIFSFindFirst() usage with msearch=false.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Make a number of updates to the netfs tracepoints:
(1) Remove a duplicate trace from netfs_unbuffered_write_iter_locked().
(2) Move the trace in netfs_wake_rreq_flag() to after the flag is cleared
so that the change appears in the trace.
(3) Differentiate the use of netfs_rreq_trace_wait/woke_queue symbols.
(4) Don't do so many trace emissions in the wait functions as some of them
are redundant.
(5) In netfs_collect_read_results(), differentiate a subreq that's being
abandoned vs one that has been consumed in a regular way.
(6) Add a tracepoint to indicate the call to ->ki_complete().
(7) Don't double-increment the subreq_counter when retrying a write.
(8) Move the netfs_sreq_trace_io_progress tracepoint within cifs code to
just MID_RESPONSE_RECEIVED and add different tracepoints for other MID
states and note check failure.
Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Paulo Alcantara <pc@manguebit.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
Link: https://lore.kernel.org/20250701163852.2171681-14-dhowells@redhat.com
cc: Steve French <sfrench@samba.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Merge tag 'v6.16-rc-part1-smb-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client updates from Steve French:
- multichannel fixes (mostly reconnect related), and clarification of
locking documentation
- automount null pointer check fix
- fixes to add support for ParentLeaseKey
- minor cleanup
- smb1/cifs fixes
* tag 'v6.16-rc-part1-smb-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: update the lock ordering comments with new mutex
cifs: dns resolution is needed only for primary channel
cifs: update dstaddr whenever channel iface is updated
cifs: reset connections for all channels when reconnect requested
smb: client: use ParentLeaseKey in cifs_do_create
smb: client: use ParentLeaseKey in open_cached_dir
smb: client: add ParentLeaseKey support
cifs: Fix cifs_query_path_info() for Windows NT servers
cifs: Fix validation of SMB1 query reparse point response
cifs: Correctly set SMB1 SessionKey field in Session Setup Request
cifs: Fix encoding of SMB1 Session Setup NTLMSSP Request in non-UNICODE mode
smb: client: add NULL check in automount_fullpath
smb: client: Remove an unused function and variable
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Merge tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull netfs updates from Christian Brauner:
- The main API document has been extensively updated/rewritten
- Fix an oops in write-retry due to mis-resetting the I/O iterator
- Fix the recording of transferred bytes for short DIO reads
- Fix a request's work item to not require a reference, thereby
avoiding the need to get rid of it in BH/IRQ context
- Fix waiting and waking to be consistent about the waitqueue used
- Remove NETFS_SREQ_SEEK_DATA_READ, NETFS_INVALID_WRITE,
NETFS_ICTX_WRITETHROUGH, NETFS_READ_HOLE_CLEAR,
NETFS_RREQ_DONT_UNLOCK_FOLIOS, and NETFS_RREQ_BLOCKED
- Reorder structs to eliminate holes
- Remove netfs_io_request::ractl
- Only provide proc_link field if CONFIG_PROC_FS=y
- Remove folio_queue::marks3
- Fix undifferentiation of DIO reads from unbuffered reads
* tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
netfs: Fix undifferentiation of DIO reads from unbuffered reads
netfs: Fix wait/wake to be consistent about the waitqueue used
netfs: Fix the request's work item to not require a ref
netfs: Fix setting of transferred bytes with short DIO reads
netfs: Fix oops in write-retry from mis-resetting the subreq iterator
fs/netfs: remove unused flag NETFS_RREQ_BLOCKED
fs/netfs: remove unused flag NETFS_RREQ_DONT_UNLOCK_FOLIOS
folio_queue: remove unused field `marks3`
fs/netfs: declare field `proc_link` only if CONFIG_PROC_FS=y
fs/netfs: remove `netfs_io_request.ractl`
fs/netfs: reorder struct fields to eliminate holes
fs/netfs: remove unused enum choice NETFS_READ_HOLE_CLEAR
fs/netfs: remove unused flag NETFS_ICTX_WRITETHROUGH
fs/netfs: remove unused source NETFS_INVALID_WRITE
fs/netfs: remove unused flag NETFS_SREQ_SEEK_DATA_READ
Validate the SMB1 query reparse point response per [MS-CIFS] section
2.2.7.2 NT_TRANSACT_IOCTL.
NT_TRANSACT_IOCTL response contains one word long setup data after which is
ByteCount member. So check that SetupCount is 1 before trying to read and
use ByteCount member.
Output setup data contains ReturnedDataLen member which is the output
length of executed IOCTL command by remote system. So check that output was
not truncated before transferring over network.
Change MaxSetupCount of NT_TRANSACT_IOCTL request from 4 to 1 as io_rsp
structure already expects one word long output setup data. This should
prevent server sending incompatible structure (in case it would be extended
in future, which is unlikely).
Change MaxParameterCount of NT_TRANSACT_IOCTL request from 2 to 0 as
NT IOCTL does not have any documented output parameters and this function
does not parse any output parameters at all.
Fixes: ed3e0a149b ("smb: client: implement ->query_reparse_point() for SMB1")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
[MS-CIFS] specification in section 2.2.4.53.1 where is described
SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says:
The client MUST set this field to be equal to the SessionKey field in
the SMB_COM_NEGOTIATE Response for this SMB connection.
Linux SMB client currently set this field to zero. This is working fine
against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>:
Windows NT Server ignores the client's SessionKey.
For compatibility with [MS-CIFS], set this SessionKey field in Session
Setup Request to value retrieved from Negotiate response.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When the netfs_io_request struct's work item is queued, it must be supplied
with a ref to the work item struct to prevent it being deallocated whilst
on the queue or whilst it is being processed. This is tricky to manage as
we have to get a ref before we try and queue it and then we may find it's
already queued and is thus already holding a ref - in which case we have to
try and get rid of the ref again.
The problem comes if we're in BH or IRQ context and need to drop the ref:
if netfs_put_request() reduces the count to 0, we have to do the cleanup -
but the cleanup may need to wait.
Fix this by adding a new work item to the request, ->cleanup_work, and
dispatching that when the refcount hits zero. That can then synchronously
cancel any outstanding work on the main work item before doing the cleanup.
Adding a new work item also deals with another problem upstream where it's
sometimes changing the work func in the put function and requeuing it -
which has occasionally in the past caused the cleanup to happen
incorrectly.
As a bonus, this allows us to get rid of the 'was_async' parameter from a
bunch of functions. This indicated whether the put function might not be
permitted to sleep.
Fixes: 3d3c950467 ("netfs: Provide readahead and readpage netfs helpers")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/20250519090707.2848510-4-dhowells@redhat.com
cc: Paulo Alcantara <pc@manguebit.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Steve French <stfrench@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Function CIFSSMBSetPathInfo() is not supported by non-NT servers and
returns error. Fallback code via open filehandle and CIFSSMBSetFileInfo()
does not work neither because CIFS_open() works also only on NT server.
Therefore currently the whole smb_set_file_info() function as a SMB1
callback for the ->set_file_info() does not work with older non-NT SMB
servers, like Win9x and others.
This change implements fallback code in smb_set_file_info() which will
works with any server and allows to change time values and also to set or
clear read-only attributes.
To make existing fallback code via CIFSSMBSetFileInfo() working with also
non-NT servers, it is needed to change open function from CIFS_open()
(which is NT specific) to cifs_open_file() which works with any server
(this is just a open wrapper function which choose the correct open
function supported by the server).
CIFSSMBSetFileInfo() is working also on non-NT servers, but zero time
values are not treated specially. So first it is needed to fill all time
values if some of them are missing, via cifs_query_path_info() call.
There is another issue, opening file in write-mode (needed for changing
attributes) is not possible when the file has read-only attribute set.
The only option how to clear read-only attribute is via SMB_COM_SETATTR
command. And opening directory is not possible neither and here the
SMB_COM_SETATTR command is the only option how to change attributes.
And CIFSSMBSetFileInfo() does not honor setting read-only attribute, so
for setting is also needed to use SMB_COM_SETATTR command.
Existing code in cifs_query_path_info() is already using SMB_COM_GETATTR as
a fallback code path (function SMBQueryInformation()), so introduce a new
function SMBSetInformation which will implement SMB_COM_SETATTR command.
My testing showed that Windows XP SMB1 client is also using SMB_COM_SETATTR
command for setting or clearing read-only attribute against non-NT server.
So this can prove that this is the correct way how to do it.
With this change it is possible set all 4 time values and all attributes,
including clearing and setting read-only bit on non-NT SMB servers.
Tested against Win98 SMB1 server.
This change fixes "touch" command which was failing when called on existing
file. And fixes also "chmod +w" and "chmod -w" commands which were also
failing (as they are changing read-only attribute).
Note that this change depends on following change
"cifs: Improve cifs_query_path_info() and cifs_query_file_info()"
as it require to query all 4 time attribute values.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
When converting access_flags to SMBOPEN mode, check for all possible access
flags, not only GENERIC_READ and GENERIC_WRITE flags.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB1 protocol supports non-UNICODE (8-bit OEM character set) and
UNICODE (UTF-16) modes.
Linux SMB1 client implements both of them but currently does not allow to
choose non-UNICODE mode when SMB1 server announce UNICODE mode support.
This change adds a new mount option -o nounicode to disable UNICODE mode
and force usage of non-UNICODE (8-bit OEM character set) mode.
This allows to test non-UNICODE implementation of Linux SMB1 client against
any SMB1 server, including modern and recent Windows SMB1 server.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Currently ->get_acl() callback always create request for OWNER, GROUP and
DACL, even when only DACLs was requested by user. Change API callback to
request only information for which the caller asked. Therefore when only
DACLs requested, then SMB client will prepare and send DACL-only request.
This change fixes retrieving of "system.cifs_acl" and "system.smb3_acl"
xattrs to contain only DACL structure as documented.
Note that setting/changing of "system.cifs_acl" and "system.smb3_acl"
xattrs already takes only DACL structure and ignores all other fields.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Do not attempt to query or create reparse point when server fs does not
support it. This will prevent creating unusable empty object on the server.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
If @server->tcpStatus is set to CifsNeedReconnect after acquiring
@ses->session_mutex in smb2_reconnect() or cifs_reconnect_tcon(), it
means that a concurrent thread failed to negotiate, in which case the
server is no longer responding to any SMB requests, so there is no
point making the caller retry the IO by returning -EAGAIN.
Fix this by returning -EHOSTDOWN to the callers on soft mounts.
Cc: David Howells <dhowells@redhat.com>
Reported-by: Jay Shin <jaeshin@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix cifs_readv_callback() to call netfs_read_subreq_terminated() rather
than queuing the subrequest work item (which is unset). Also call the
I/O progress tracepoint.
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Fixes: e2d46f2ec3 ("netfs: Change the read result collector to only use one work item")
Reported-by: Jean-Christophe Guillain <jean-christophe@guillain.net>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219793
Tested-by: Jean-Christophe Guillain <jean-christophe@guillain.net>
Tested-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
SMB1 callback get_cifs_acl_by_fid() currently ignores its last argument and
therefore ignores request for SACL_SECINFO. Fix this issue by correctly
propagating info argument from get_cifs_acl() and get_cifs_acl_by_fid() to
CIFSSMBGetCIFSACL() function and pass SACL_SECINFO when requested.
For accessing SACLs it is needed to open object with SYSTEM_SECURITY
access. Pass this flag when trying to get or set SACLs.
Same logic is in the SMB2+ code path.
This change fixes getting and setting of "system.cifs_ntsd_full" and
"system.smb3_ntsd_full" xattrs over SMB1 as currently it silentely ignored
SACL part of passed xattr buffer.
Fixes: 3970acf7dd ("SMB3: Add support for getting and setting SACLs")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Merge tag 'vfs-6.14-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs netfs updates from Christian Brauner:
"This contains read performance improvements and support for monolithic
single-blob objects that have to be read/written as such (e.g. AFS
directory contents). The implementation of the two parts is interwoven
as each makes the other possible.
- Read performance improvements
The read performance improvements are intended to speed up some
loss of performance detected in cifs and to a lesser extend in afs.
The problem is that we queue too many work items during the
collection of read results: each individual subrequest is collected
by its own work item, and then they have to interact with each
other when a series of subrequests don't exactly align with the
pattern of folios that are being read by the overall request.
Whilst the processing of the pages covered by individual
subrequests as they complete potentially allows folios to be woken
in parallel and with minimum delay, it can shuffle wakeups for
sequential reads out of order - and that is the most common I/O
pattern.
The final assessment and cleanup of an operation is then held up
until the last I/O completes - and for a synchronous sequential
operation, this means the bouncing around of work items just adds
latency.
Two changes have been made to make this work:
(1) All collection is now done in a single "work item" that works
progressively through the subrequests as they complete (and
also dispatches retries as necessary).
(2) For readahead and AIO, this work item be done on a workqueue
and can run in parallel with the ultimate consumer of the data;
for synchronous direct or unbuffered reads, the collection is
run in the application thread and not offloaded.
Functions such as smb2_readv_callback() then just tell netfslib
that the subrequest has terminated; netfslib does a minimal bit of
processing on the spot - stat counting and tracing mostly - and
then queues/wakes up the worker. This simplifies the logic as the
collector just walks sequentially through the subrequests as they
complete and walks through the folios, if buffered, unlocking them
as it goes. It also keeps to a minimum the amount of latency
injected into the filesystem's low-level I/O handling
The way netfs supports filesystems using the deprecated
PG_private_2 flag is changed: folios are flagged and added to a
write request as they complete and that takes care of scheduling
the writes to the cache. The originating read request can then just
unlock the pages whatever happens.
- Single-blob object support
Single-blob objects are files for which the content of the file
must be read from or written to the server in a single operation
because reading them in parts may yield inconsistent results. AFS
directories are an example of this as there exists the possibility
that the contents are generated on the fly and would differ between
reads or might change due to third party interference.
Such objects will be written to and retrieved from the cache if one
is present, though we allow/may need to propose multiple
subrequests to do so. The important part is that read from/write to
the *server* is monolithic.
Single blob reading is, for the moment, fully synchronous and does
result collection in the application thread and, also for the
moment, the API is supplied the buffer in the form of a folio_queue
chain rather than using the pagecache.
- Related afs changes
This series makes a number of changes to the kafs filesystem,
primarily in the area of directory handling:
- AFS's FetchData RPC reply processing is made partially
asynchronous which allows the netfs_io_request's outstanding
operation counter to be removed as part of reducing the
collection to a single work item.
- Directory and symlink reading are plumbed through netfslib using
the single-blob object API and are now cacheable with fscache.
This also allows the afs_read struct to be eliminated and
netfs_io_subrequest to be used directly instead.
- Directory and symlink content are now stored in a folio_queue
buffer rather than in the pagecache. This means we don't require
the RCU read lock and xarray iteration to access it, and folios
won't randomly disappear under us because the VM wants them
back.
- The vnode operation lock is changed from a mutex struct to a
private lock implementation. The problem is that the lock now
needs to be dropped in a separate thread and mutexes don't
permit that.
- When a new directory or symlink is created, we now initialise it
locally and mark it valid rather than downloading it (we know
what it's likely to look like).
- We now use the in-directory hashtable to reduce the number of
entries we need to scan when doing a lookup. The edit routines
have to maintain the hash chains.
- Cancellation (e.g. by signal) of an async call after the
rxrpc_call has been set up is now offloaded to the worker thread
as there will be a notification from rxrpc upon completion. This
avoids a double cleanup.
- A "rolling buffer" implementation is created to abstract out the
two separate folio_queue chaining implementations I had (one for
read and one for write).
- Functions are provided to create/extend a buffer in a folio_queue
chain and tear it down again.
This is used to handle AFS directories, but could also be used to
create bounce buffers for content crypto and transport crypto.
- The was_async argument is dropped from netfs_read_subreq_terminated()
Instead we wake the read collection work item by either queuing it
or waking up the app thread.
- We don't need to use BH-excluding locks when communicating between
the issuing thread and the collection thread as neither of them now
run in BH context.
- Also included are a number of new tracepoints; a split of the
netfslib write collection code to put retrying into its own file
(it gets more complicated with content encryption).
- There are also some minor fixes AFS included, including fixing the
AFS directory format struct layout, reducing some directory
over-invalidation and making afs_mkdir() translate EEXIST to
ENOTEMPY (which is not available on all systems the servers
support).
- Finally, there's a patch to try and detect entry into the folio
unlock function with no folio_queue structs in the buffer (which
isn't allowed in the cases that can get there).
This is a debugging patch, but should be minimal overhead"
* tag 'vfs-6.14-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (31 commits)
netfs: Report on NULL folioq in netfs_writeback_unlock_folios()
afs: Add a tracepoint for afs_read_receive()
afs: Locally initialise the contents of a new symlink on creation
afs: Use the contained hashtable to search a directory
afs: Make afs_mkdir() locally initialise a new directory's content
netfs: Change the read result collector to only use one work item
afs: Make {Y,}FS.FetchData an asynchronous operation
afs: Fix cleanup of immediately failed async calls
afs: Eliminate afs_read
afs: Use netfslib for symlinks, allowing them to be cached
afs: Use netfslib for directories
afs: Make afs_init_request() get a key if not given a file
netfs: Add support for caching single monolithic objects such as AFS dirs
netfs: Add functions to build/clean a buffer in a folio_queue
afs: Add more tracepoints to do with tracking validity
cachefiles: Add auxiliary data trace
cachefiles: Add some subrequest tracepoints
netfs: Remove some extraneous directory invalidations
afs: Fix directory format encoding struct
afs: Fix EEXIST error returned from afs_rmdir() to be ENOTEMPTY
...
SMB1 shares the mount and remount code paths with SMB2/3 and already
supports password rotation in some scenarios. This patch extends the
password rotation support to SMB1 reconnects as well.
Cc: stable@vger.kernel.org
Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Change the way netfslib collects read results to do all the collection for
a particular read request using a single work item that walks along the
subrequest queue as subrequests make progress or complete, unlocking folios
progressively rather than doing the unlock in parallel as parallel requests
come in.
The code is remodelled to be more like the write-side code, though only
using a single stream. This makes it more directly comparable and thus
easier to duplicate fixes between the two sides.
This has a number of advantages:
(1) It's simpler. There doesn't need to be a complex donation mechanism
to handle mismatches between the size and alignment of subrequests and
folios. The collector unlocks folios as the subrequests covering each
complete.
(2) It should cause less scheduler overhead as there's a single work item
in play unlocking pages in parallel when a read gets split up into a
lot of subrequests instead of one per subrequest.
Whilst the parallellism is nice in theory, in practice, the vast
majority of loads are sequential reads of the whole file, so
committing a bunch of threads to unlocking folios out of order doesn't
help in those cases.
(3) It should make it easier to implement content decryption. A folio
cannot be decrypted until all the requests that contribute to it have
completed - and, again, most loads are sequential and so, most of the
time, we want to begin decryption sequentially (though it's great if
the decryption can happen in parallel).
There is a disadvantage in that we're losing the ability to decrypt and
unlock things on an as-things-arrive basis which may affect some
applications.
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-28-dhowells@redhat.com
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
syzkaller reported recursion with a loop of three calls (netfs_rreq_assess,
netfs_retry_reads and netfs_rreq_terminated) hitting the limit of the stack
during an unbuffered or direct I/O read.
There are a number of issues:
(1) There is no limit on the number of retries.
(2) A subrequest is supposed to be abandoned if it does not transfer
anything (NETFS_SREQ_NO_PROGRESS), but that isn't checked under all
circumstances.
(3) The actual root cause, which is this:
if (atomic_dec_and_test(&rreq->nr_outstanding))
netfs_rreq_terminated(rreq, ...);
When we do a retry, we bump the rreq->nr_outstanding counter to
prevent the final cleanup phase running before we've finished
dispatching the retries. The problem is if we hit 0, we have to do
the cleanup phase - but we're in the cleanup phase and end up
repeating the retry cycle, hence the recursion.
Work around the problem by limiting the number of retries. This is based
on Lizhi Xu's patch[1], and makes the following changes:
(1) Replace NETFS_SREQ_NO_PROGRESS with NETFS_SREQ_MADE_PROGRESS and make
the filesystem set it if it managed to read or write at least one byte
of data. Clear this bit before issuing a subrequest.
(2) Add a ->retry_count member to the subrequest and increment it any time
we do a retry.
(3) Remove the NETFS_SREQ_RETRYING flag as it is superfluous with
->retry_count. If the latter is non-zero, we're doing a retry.
(4) Abandon a subrequest if retry_count is non-zero and we made no
progress.
(5) Use ->retry_count in both the write-side and the read-size.
[?] Question: Should I set a hard limit on retry_count in both read and
write? Say it hits 50, we always abandon it. The problem is that
these changes only mitigate the issue. As long as it made at least one
byte of progress, the recursion is still an issue. This patch
mitigates the problem, but does not fix the underlying cause. I have
patches that will do that, but it's an intrusive fix that's currently
pending for the next merge window.
The oops generated by KASAN looks something like:
BUG: TASK stack guard page was hit at ffffc9000482ff48 (stack is ffffc90004830000..ffffc90004838000)
Oops: stack guard page: 0000 [#1] PREEMPT SMP KASAN NOPTI
...
RIP: 0010:mark_lock+0x25/0xc60 kernel/locking/lockdep.c:4686
...
mark_usage kernel/locking/lockdep.c:4646 [inline]
__lock_acquire+0x906/0x3ce0 kernel/locking/lockdep.c:5156
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5825
local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
___slab_alloc+0x123/0x1880 mm/slub.c:3695
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3908
__slab_alloc_node mm/slub.c:3961 [inline]
slab_alloc_node mm/slub.c:4122 [inline]
kmem_cache_alloc_noprof+0x2a7/0x2f0 mm/slub.c:4141
radix_tree_node_alloc.constprop.0+0x1e8/0x350 lib/radix-tree.c:253
idr_get_free+0x528/0xa40 lib/radix-tree.c:1506
idr_alloc_u32+0x191/0x2f0 lib/idr.c:46
idr_alloc+0xc1/0x130 lib/idr.c:87
p9_tag_alloc+0x394/0x870 net/9p/client.c:321
p9_client_prepare_req+0x19f/0x4d0 net/9p/client.c:644
p9_client_zc_rpc.constprop.0+0x105/0x880 net/9p/client.c:793
p9_client_read_once+0x443/0x820 net/9p/client.c:1570
p9_client_read+0x13f/0x1b0 net/9p/client.c:1534
v9fs_issue_read+0x115/0x310 fs/9p/vfs_addr.c:74
netfs_retry_read_subrequests fs/netfs/read_retry.c:60 [inline]
netfs_retry_reads+0x153a/0x1d00 fs/netfs/read_retry.c:232
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
...
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_retry_reads+0x155e/0x1d00 fs/netfs/read_retry.c:235
netfs_rreq_assess+0x5d3/0x870 fs/netfs/read_collect.c:371
netfs_rreq_terminated+0xe5/0x110 fs/netfs/read_collect.c:407
netfs_dispatch_unbuffered_reads fs/netfs/direct_read.c:103 [inline]
netfs_unbuffered_read fs/netfs/direct_read.c:127 [inline]
netfs_unbuffered_read_iter_locked+0x12f6/0x19b0 fs/netfs/direct_read.c:221
netfs_unbuffered_read_iter+0xc5/0x100 fs/netfs/direct_read.c:256
v9fs_file_read_iter+0xbf/0x100 fs/9p/vfs_file.c:361
do_iter_readv_writev+0x614/0x7f0 fs/read_write.c:832
vfs_readv+0x4cf/0x890 fs/read_write.c:1025
do_preadv fs/read_write.c:1142 [inline]
__do_sys_preadv fs/read_write.c:1192 [inline]
__se_sys_preadv fs/read_write.c:1187 [inline]
__x64_sys_preadv+0x22d/0x310 fs/read_write.c:1187
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
Fixes: ee4cdf7ba8 ("netfs: Speed up buffered reading")
Closes: https://syzkaller.appspot.com/bug?extid=1fc6f64c40a9d143cfb6
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241108034020.3695718-1-lizhi.xu@windriver.com/ [1]
Link: https://lore.kernel.org/r/20241213135013.2964079-9-dhowells@redhat.com
Tested-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Suggested-by: Lizhi Xu <lizhi.xu@windriver.com>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: v9fs@lists.linux.dev
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Reported-by: syzbot+885c03ad650731743489@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
cifs_tree_connect() no longer uses ioctl, so allow sessions to be
reconnected when sending ioctls.
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We can access local_nls directly from @tcon->ses, so there is no need
to pass it as parameter in cifs_tree_connect().
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Like commit f1f047bd7c ("smb: client: Fix -Wstringop-overflow issues"),
adjust the memcpy() destination address to be based off the surrounding
object rather than based off the 4-byte "Protocol" member. This avoids a
build-time warning when compiling under CONFIG_FORTIFY_SOURCE with GCC 15:
In function 'fortify_memcpy_chk',
inlined from 'CIFSSMBSetPathInfo' at ../fs/smb/client/cifssmb.c:5358:2:
../include/linux/fortify-string.h:571:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
571 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
CIFSSMBCopy() is unused, remove it.
It seems to have been that way pre-git; looking in a historic
archive, I think it landed around May 2004 in Linus'
BKrev: 40ab7591J_OgkpHW-qhzZukvAUAw9g
and was unused back then.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Tom Talpey <tom@talpey.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Merge tag 'v6.12-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client updates from Steve French:
- cleanups (moving duplicated code, removing unused code etc)
- fixes relating to "sfu" mount options (for better handling special
file types)
- SMB3.1.1 compression fixes/improvements
* tag 'v6.12-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6: (24 commits)
smb: client: fix compression heuristic functions
cifs: Update SFU comments about fifos and sockets
cifs: Add support for creating SFU symlinks
smb: use LIST_HEAD() to simplify code
cifs: Recognize SFU socket type
cifs: Show debug message when SFU Fifo type was detected
cifs: Put explicit zero byte into SFU block/char types
cifs: Add support for reading SFU symlink location
cifs: Fix recognizing SFU symlinks
smb: client: compress: fix an "illegal accesses" issue
smb: client: compress: fix a potential issue of freeing an invalid pointer
smb: client: compress: LZ77 code improvements cleanup
smb: client: insert compression check/call on write requests
smb3: mark compression as CONFIG_EXPERIMENTAL and fix missing compression operation
cifs: Remove obsoleted declaration for cifs_dir_open
smb: client: Use min() macro
cifs: convert to use ERR_CAST()
smb: add comment to STATUS_MCA_OCCURED
smb: move SMB2 Status code to common header file
smb: move some duplicate definitions to common/smbacl.h
...
In SFU mode, activated by -o sfu mount option is now also support for
creating new fifos and sockets.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Fix an upstream merge resolution issue[1]. Prior to the netfs read
healpers, the SMB1 asynchronous read callback, cifs_readv_worker()
performed the cleanup for the operation in the network message processing
loop, potentially slowing down the processing of incoming SMB messages.
With commit a68c74865f ("cifs: Fix SMB1 readv/writev callback in the same
way as SMB2/3"), this was moved to a worker thread (as is done in the
SMB2/3 transport variant). However, the "was_async" argument to
netfs_subreq_terminated (which was originally incorrectly "false" got
flipped to "true" - which was then incorrect because, being in a kernel
thread, it's not in an async context).
This got corrected in the sample merge[2], but Linus, not unreasonably,
switched it back to its previous value.
Note that this value tells netfslib whether or not it can run sleepable
stuff or stuff that takes a long time, such as retries and cleanups, in the
calling thread, or whether it should offload to a worker thread.
Fix this so that it is "false". The callback to netfslib in both SMB1 and
SMB2/3 now gets offloaded from the network message thread to a separate
worker thread and thus it's fine to do the slow work in this thread.
Fixes: 35219bc5c7 ("Merge tag 'vfs-6.12.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <stfrench@microsoft.com>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Christian Brauner <brauner@kernel.org>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/CAHk-=wjr8fxk20-wx=63mZruW1LTvBvAKya1GQ1EhyzXb-okMA@mail.gmail.com/ [1]
Link: https://lore.kernel.org/linux-fsdevel/20240913-vfs-netfs-39ef6f974061@brauner/ [2]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'vfs-6.12.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull netfs updates from Christian Brauner:
"This contains the work to improve read/write performance for the new
netfs library.
The main performance enhancing changes are:
- Define a structure, struct folio_queue, and a new iterator type,
ITER_FOLIOQ, to hold a buffer as a replacement for ITER_XARRAY. See
that patch for questions about naming and form.
ITER_FOLIOQ is provided as a replacement for ITER_XARRAY. The
problem with an xarray is that accessing it requires the use of a
lock (typically the RCU read lock) - and this means that we can't
supply iterate_and_advance() with a step function that might sleep
(crypto for example) without having to drop the lock between pages.
ITER_FOLIOQ is the iterator for a chain of folio_queue structs,
where each folio_queue holds a small list of folios. A folio_queue
struct is a simpler structure than xarray and is not subject to
concurrent manipulation by the VM. folio_queue is used rather than
a bvec[] as it can form lists of indefinite size, adding to one end
and removing from the other on the fly.
- Provide a copy_folio_from_iter() wrapper.
- Make cifs RDMA support ITER_FOLIOQ.
- Use folio queues in the write-side helpers instead of xarrays.
- Add a function to reset the iterator in a subrequest.
- Simplify the write-side helpers to use sheaves to skip gaps rather
than trying to work out where gaps are.
- In afs, make the read subrequests asynchronous, putting them into
work items to allow the next patch to do progressive
unlocking/reading.
- Overhaul the read-side helpers to improve performance.
- Fix the caching of a partial block at the end of a file.
- Allow a store to be cancelled.
Then some changes for cifs to make it use folio queues instead of
xarrays for crypto bufferage:
- Use raw iteration functions rather than manually coding iteration
when hashing data.
- Switch to using folio_queue for crypto buffers.
- Remove the xarray bits.
Make some adjustments to the /proc/fs/netfs/stats file such that:
- All the netfs stats lines begin 'Netfs:' but change this to
something a bit more useful.
- Add a couple of stats counters to track the numbers of skips and
waits on the per-inode writeback serialisation lock to make it
easier to check for this as a source of performance loss.
Miscellaneous work:
- Ensure that the sb_writers lock is taken around
vfs_{set,remove}xattr() in the cachefiles code.
- Reduce the number of conditional branches in netfs_perform_write().
- Move the CIFS_INO_MODIFIED_ATTR flag to the netfs_inode struct and
remove cifs_post_modify().
- Move the max_len/max_nr_segs members from netfs_io_subrequest to
netfs_io_request as they're only needed for one subreq at a time.
- Add an 'unknown' source value for tracing purposes.
- Remove NETFS_COPY_TO_CACHE as it's no longer used.
- Set the request work function up front at allocation time.
- Use bh-disabling spinlocks for rreq->lock as cachefiles completion
may be run from block-filesystem DIO completion in softirq context.
- Remove fs/netfs/io.c"
* tag 'vfs-6.12.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (25 commits)
docs: filesystems: corrected grammar of netfs page
cifs: Don't support ITER_XARRAY
cifs: Switch crypto buffer to use a folio_queue rather than an xarray
cifs: Use iterate_and_advance*() routines directly for hashing
netfs: Cancel dirty folios that have no storage destination
cachefiles, netfs: Fix write to partial block at EOF
netfs: Remove fs/netfs/io.c
netfs: Speed up buffered reading
afs: Make read subreqs async
netfs: Simplify the writeback code
netfs: Provide an iterator-reset function
netfs: Use new folio_queue data type and iterator instead of xarray iter
cifs: Provide the capability to extract from ITER_FOLIOQ to RDMA SGEs
iov_iter: Provide copy_folio_from_iter()
mm: Define struct folio_queue and ITER_FOLIOQ to handle a sequence of folios
netfs: Use bh-disabling spinlocks for rreq->lock
netfs: Set the request work function upon allocation
netfs: Remove NETFS_COPY_TO_CACHE
netfs: Reserve netfs_sreq_source 0 as unset/unknown
netfs: Move max_len/max_nr_segs from netfs_io_subrequest to netfs_io_stream
...
Preparation for moving acl definitions to new common header file.
Use the following shell command to rename:
find fs/smb/client -type f -exec sed -i \
's/struct cifs_ntsd/struct smb_ntsd/g' {} +
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Improve the efficiency of buffered reads in a number of ways:
(1) Overhaul the algorithm in general so that it's a lot more compact and
split the read submission code between buffered and unbuffered
versions. The unbuffered version can be vastly simplified.
(2) Read-result collection is handed off to a work queue rather than being
done in the I/O thread. Multiple subrequests can be processes
simultaneously.
(3) When a subrequest is collected, any folios it fully spans are
collected and "spare" data on either side is donated to either the
previous or the next subrequest in the sequence.
Notes:
(*) Readahead expansion is massively slows down fio, presumably because it
causes a load of extra allocations, both folio and xarray, up front
before RPC requests can be transmitted.
(*) RDMA with cifs does appear to work, both with SIW and RXE.
(*) PG_private_2-based reading and copy-to-cache is split out into its own
file and altered to use folio_queue. Note that the copy to the cache
now creates a new write transaction against the cache and adds the
folios to be copied into it. This allows it to use part of the
writeback I/O code.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/20240814203850.2240469-20-dhowells@redhat.com/ # v2
Signed-off-by: Christian Brauner <brauner@kernel.org>
Port a number of SMB2/3 async readv/writev fixes to the SMB1 transport:
commit a88d609036
cifs: Don't advance the I/O iterator before terminating subrequest
commit ce5291e560
cifs: Defer read completion
commit 1da29f2c39
netfs, cifs: Fix handling of short DIO read
Fixes: 3ee1a1fc39 ("cifs: Cut over to using netfslib")
Signed-off-by: David Howells <dhowells@redhat.com>
Reported-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Fixes: d08089f649 ("cifs: Change the I/O paths to use an iterator rather than a page list")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Move the reference pid from the cifs_io_subrequest struct to the
cifs_io_request struct as it's the same for all subreqs of a particular
request.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Paulo Alcantara <pc@manguebit.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>
Make the cifs filesystem use netfslib to handle reading and writing on
behalf of cifs. The changes include:
(1) Various read_iter/write_iter type functions are turned into wrappers
around netfslib API functions or are pointed directly at those
functions:
cifs_file_direct{,_nobrl}_ops switch to use
netfs_unbuffered_read_iter and netfs_unbuffered_write_iter.
Large pieces of code that will be removed are #if'd out and will be removed
in subsequent patches.
[?] Why does cifs mark the page dirty in the destination buffer of a DIO
read? Should that happen automatically? Does netfs need to do that?
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Use more fields from netfs_io_subrequest instead of those incorporated into
cifs_io_subrequest from cifs_readdata and cifs_writedata.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Replace the cifs_writedata struct with the same wrapper around
netfs_io_subrequest that was used to replace cifs_readdata.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
Netfslib has a facility whereby the allocation for netfs_io_subrequest can
be increased to so that filesystem-specific data can be tagged on the end.
Prepare to use this by making a struct, cifs_io_subrequest, that wraps
netfs_io_subrequest, and absorb struct cifs_readdata into it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
In cifssmb.c:
Using strncpy with a length argument equal to strlen(src) is generally
dangerous because it can cause string buffers to not be NUL-terminated.
In this case, however, there was extra effort made to ensure the buffer
was NUL-terminated via a manual NUL-byte assignment. In an effort to rid
the kernel of strncpy() use, let's swap over to using strscpy() which
guarantees NUL-termination on the destination buffer.
To handle the case where ea_name is NULL, let's use the ?: operator to
substitute in an empty string, thereby allowing strscpy to still
NUL-terminate the destintation string.
Interesting note: this flex array buffer may go on to also have some
value encoded after the NUL-termination:
| if (ea_value_len)
| memcpy(parm_data->list.name + name_len + 1,
| ea_value, ea_value_len);
Now for smb2ops.c and smb2transport.c:
Both of these cases are simple, strncpy() is used to copy string
literals which have a length less than the destination buffer's size. We
can simply swap in the new 2-argument version of strscpy() introduced in
Commit e6584c3964 ("string: Allow 2-argument strscpy()").
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
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Merge tag '6.9-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client updates from Steve French:
- fix for folios/netfs data corruption in cifs_extend_writeback
- additional tracepoint added
- updates for special files and symlinks: improvements to allow
selecting use of either WSL or NFS reparse point format on creating
special files
- allocation size improvement for cached files
- minor cleanup patches
- fix to allow changing the password on remount when password for the
session is expired.
- lease key related fixes: caching hardlinked files, deletes of
deferred close files, and an important fix to better reuse lease keys
for compound operations, which also can avoid lease break timeouts
when low on credits
- fix potential data corruption with write/readdir races
- compression cleanups and a fix for compression headers
* tag '6.9-rc-smb3-client-fixes-part1' of git://git.samba.org/sfrench/cifs-2.6: (24 commits)
cifs: update internal module version number for cifs.ko
smb: common: simplify compression headers
smb: common: fix fields sizes in compression_pattern_payload_v1
smb: client: negotiate compression algorithms
smb3: add dynamic trace point for ioctls
cifs: Fix writeback data corruption
smb: client: return reparse type in /proc/mounts
smb: client: set correct d_type for reparse DFS/DFSR and mount point
smb: client: parse uid, gid, mode and dev from WSL reparse points
smb: client: introduce SMB2_OP_QUERY_WSL_EA
smb: client: Fix a NULL vs IS_ERR() check in wsl_set_xattrs()
smb: client: add support for WSL reparse points
smb: client: reduce number of parameters in smb2_compound_op()
smb: client: fix potential broken compound request
smb: client: move most of reparse point handling code to common file
smb: client: introduce reparse mount option
smb: client: retry compound request without reusing lease
smb: client: do not defer close open handles to deleted files
smb: client: reuse file lease key in compound operations
smb3: update allocation size more accurately on write completion
...
Currently, when a rename, unlink or set path size compound operation
is requested on a file that has a lot of dirty pages to be written
to the server, we do not send the lease key for these requests. As a
result, the server can assume that this request is from a new client, and
send a lease break notification to the same client, on the same
connection. As a response to the lease break, the client can consume
several credits to write the dirty pages to the server. Depending on the
server's credit grant implementation, the server can stop granting more
credits to this connection, and this can cause a deadlock (which can only
be resolved when the lease timer on the server expires).
One of the problems here is that the client is sending no lease key,
even if it has a lease for the file. This patch fixes the problem by
reusing the existing lease key on the file for rename, unlink and set path
size compound operations so that the client does not break its own lease.
A very trivial example could be a set of commands by a client that
maintains open handle (for write) to a file and then tries to copy the
contents of that file to another one, eg.,
tail -f /dev/null > myfile &
mv myfile myfile2
Presently, the network capture on the client shows that the move (or
rename) would trigger a lease break on the same client, for the same file.
With the lease key reused, the lease break request-response overhead is
eliminated, thereby reducing the roundtrips performed for this set of
operations.
The patch fixes the bug described above and also provides perf benefit.
Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Most of the existing APIs have remained the same, but subsystems that
access file_lock fields directly need to reach into struct
file_lock_core now.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-44-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In a future patch, we're going to split file leases into their own
structure. Since a lot of the underlying machinery uses the same fields
move those into a new file_lock_core, and embed that inside struct
file_lock.
For now, add some macros to ensure that we can continue to build while
the conversion is in progress.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-17-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
smb2_compound_op(SMB2_OP_GET_REPARSE) already checks if ioctl response
has a valid reparse data buffer's length, so there's no need to check
it again in parse_reparse_point().
In order to get rid of duplicate check, validate reparse data buffer's
length also in cifs_query_reparse_point().
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The client was sending an SMB2_CREATE request without setting
OPEN_REPARSE_POINT flag thus failing the entire hardlink operation.
Fix this by setting OPEN_REPARSE_POINT in create options for
SMB2_CREATE request when the source inode is a repase point.
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
The client was sending an SMB2_CREATE request without setting
OPEN_REPARSE_POINT flag thus failing the entire rename operation.
Fix this by setting OPEN_REPARSE_POINT in create options for
SMB2_CREATE request when the source inode is a repase point.
Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
