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path: root/fs/cifs/cached_dir.c
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2022-10-19cifs: drop the lease for cached directories on rmdir or renameRonnie Sahlberg1-0/+21
When we delete or rename a directory we must also drop any cached lease we have on the directory. Fixes: a350d6e73f5e ("cifs: enable caching of directories for which a lease is held") Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-18cifs: set rc to -ENOENT if we can not get a dentry for the cached dirRonnie Sahlberg1-2/+4
We already set rc to this return code further down in the function but we can set it earlier in order to suppress a smash warning. Also fix a false positive for Coverity. The reason this is a false positive is that this happens during umount after all files and directories have been closed but mosetting on ->on_list to suppress the warning. Reported-by: Dan carpenter <dan.carpenter@oracle.com> Reported-by: coverity-bot <keescook+coverity-bot@chromium.org> Addresses-Coverity-ID: 1525256 ("Concurrent data access violations") Fixes: a350d6e73f5e ("cifs: enable caching of directories for which a lease is held") Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-18cifs: use LIST_HEAD() and list_move() to simplify codeYang Yingliang1-8/+4
list_head can be initialized automatically with LIST_HEAD() instead of calling INIT_LIST_HEAD(). Using list_move() instead of list_del() and list_add(). Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-13cifs: find and use the dentry for cached non-root directories alsoRonnie Sahlberg1-14/+49
This allows us to use cached attributes for the entries in a cached directory for as long as a lease is held on the directory itself. Previously we have always allowed "used cached attributes for 1 second" but this extends this to the lifetime of the lease as well as making the caching safer. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-13cifs: enable caching of directories for which a lease is heldRonnie Sahlberg1-182/+246
This expands the directory caching to now cache an open handle for all directories (up to a maximum) and not just the root directory. In this patch, locking and refcounting is intended to work as so: The main function to get a reference to a cached handle is find_or_create_cached_dir() called from open_cached_dir() These functions are protected under the cfid_list_lock spin-lock to make sure we do not race creating new references for cached dirs with deletion of expired ones. An successful open_cached_dir() will take out 2 references to the cfid if this was the very first and successful call to open the directory and it acquired a lease from the server. One reference is for the lease and the other is for the cfid that we return. The is lease reference is tracked by cfid->has_lease. If the directory already has a handle with an active lease, then we just take out one new reference for the cfid and return it. It can happen that we have a thread that tries to open a cached directory where we have a cfid already but we do not, yet, have a working lease. In this case we will just return NULL, and this the caller will fall back to the case when no handle was available. In this model the total number of references we have on a cfid is 1 for while the handle is open and we have a lease, and one additional reference for each open instance of a cfid. Once we get a lease break (cached_dir_lease_break()) we remove the cfid from the list under the spinlock. This prevents any new threads to use it, and we also call smb2_cached_lease_break() via the work_queue in order to drop the reference we got for the lease (we drop it outside of the spin-lock.) Anytime a thread calls close_cached_dir() we also drop a reference to the cfid. When the last reference to the cfid is released smb2_close_cached_fid() will be invoked which will drop the reference ot the dentry we held for this cfid and it will also, if we the handle is open/has a lease also call SMB2_close() to close the handle on the server. Two events require special handling: invalidate_all_cached_dirs() this function is called from SMB2_tdis() and cifs_mark_open_files_invalid(). In both cases the tcon is either gone already or will be shortly so we do not need to actually close the handles. They will be dropped server side as part of the tcon dropping. But we have to be careful about a potential race with a concurrent lease break so we need to take out additional refences to avoid the cfid from being freed while we are still referencing it. free_cached_dirs() which is called from tconInfoFree(). This is called quite late in the umount process so there should no longer be any open handles or files and we can just free all the remaining data. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05cifs: store a pointer to a fid in the cfid structure instead of the structRonnie Sahlberg1-8/+55
also create a constructor that takes a path name and stores it in the fid. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05cifs: improve handlecachingRonnie Sahlberg1-4/+5
Only track the dentry for the root handle Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05cifs: Make tcon contain a wrapper structure cached_fids instead of cached_fidRonnie Sahlberg1-23/+27
This wrapper structure will later be expanded to contain a list of fids that are cached and not just the root fid. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-05smb3: add dynamic trace points for tree disconnectSteve French1-1/+1
Needed this for debugging a failing xfstest. Also change camel case for "treeName" to "tree_name" in tcon struct. Example trace output (from "trace-cmd record -e smb3_tdis*"): umount-9718 [006] ..... 5909.780244: smb3_tdis_enter: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 path=\\localhost\test umount-9718 [007] ..... 5909.780878: smb3_tdis_done: xid=206 sid=0xcf38894e tid=0x3d0b8cf8 Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-12cifs: Do not access tcon->cfids->cfid directly from is_path_accessibleRonnie Sahlberg1-4/+6
cfids will soon keep a list of cached fids so we should not access this directly from outside of cached_dir.c Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-11cifs: Add constructor/destructors for tcon->cfidRonnie Sahlberg1-43/+67
and move the structure definitions into cached_dir.h Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-11cifs: Move cached-dir functions into a separate fileRonnie Sahlberg1-0/+362
Also rename crfid to cfid to have consistent naming for this variable. This commit does not change any logic. Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Signed-off-by: Steve French <stfrench@microsoft.com>