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| author | Steve French <stfrench@microsoft.com> | 2019-09-12 17:52:54 -0500 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2019-09-16 11:43:38 -0500 |
| commit | 96d9f7ed00b86104bf03adeffc8980897e9694ab (patch) | |
| tree | 299dd0f147a74377d24262dd6ab05d835bca573a /fs/cifs | |
| parent | 3e7a02d47872081f4b6234a9f72500f1d10f060c (diff) | |
| download | linux-96d9f7ed00b86104bf03adeffc8980897e9694ab.tar.gz linux-96d9f7ed00b86104bf03adeffc8980897e9694ab.tar.bz2 linux-96d9f7ed00b86104bf03adeffc8980897e9694ab.zip | |
smb3: fix unmount hang in open_shroot
An earlier patch "CIFS: fix deadlock in cached root handling"
did not completely address the deadlock in open_shroot. This
patch addresses the deadlock.
In testing the recent patch:
smb3: improve handling of share deleted (and share recreated)
we were able to reproduce the open_shroot deadlock to one
of the target servers in unmount in a delete share scenario.
Fixes: 7e5a70ad88b1e ("CIFS: fix deadlock in cached root handling")
This is version 2 of this patch. An earlier version of this
patch "smb3: fix unmount hang in open_shroot" had a problem
found by Dan.
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Pavel Shilovsky <pshilov@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Aurelien Aptel <aaptel@suse.com>
CC: Stable <stable@vger.kernel.org>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/smb2ops.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 3672ce0bfbaf..5776d7b0a97e 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -658,6 +658,15 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) return 0; } + /* + * We do not hold the lock for the open because in case + * SMB2_open needs to reconnect, it will end up calling + * cifs_mark_open_files_invalid() which takes the lock again + * thus causing a deadlock + */ + + mutex_unlock(&tcon->crfid.fid_mutex); + if (smb3_encryption_required(tcon)) flags |= CIFS_TRANSFORM_REQ; @@ -679,7 +688,7 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) rc = SMB2_open_init(tcon, &rqst[0], &oplock, &oparms, &utf16_path); if (rc) - goto oshr_exit; + goto oshr_free; smb2_set_next_command(tcon, &rqst[0]); memset(&qi_iov, 0, sizeof(qi_iov)); @@ -692,18 +701,10 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon, struct cifs_fid *pfid) sizeof(struct smb2_file_all_info) + PATH_MAX * 2, 0, NULL); if (rc) - goto oshr_exit; + goto oshr_free; smb2_set_related(&rqst[1]); - /* - * We do not hold the lock for the open because in case - * SMB2_open needs to reconnect, it will end up calling - * cifs_mark_open_files_invalid() which takes the lock again - * thus causing a deadlock - */ - - mutex_unlock(&tcon->crfid.fid_mutex); rc = compound_send_recv(xid, ses, flags, 2, rqst, resp_buftype, rsp_iov); mutex_lock(&tcon->crfid.fid_mutex); |