| Message ID | CAH2r5mt-t0QDZk4Zz+cSs8=s=VhUW09erUBAtm8f7xXG3rHJqw@mail.gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [smb3,client] allow debugging session and tcon info to improve stats analysis and debugging | expand |
Updated patch to remove dumping of flags (tcon->Flags was already supposed to be dumped via the other ioctl (CIFS_IOC_GET_MNT_INFO) but it had a minor bug - will send followon patch for that) On Thu, Nov 9, 2023 at 3:51 PM Steve French <smfrench@gmail.com> wrote: > > [PATCH] smb3: allow debugging session and tcon info to improve stats > analysis and debugging > > When multiple mounts are to the same share from the same client it was not > possible to determine which section of /proc/fs/cifs/Stats (and DebugData) > correspond to that mount. In some recent examples this turned out to be > a significant problem when trying to analyze performance problems - since > there are many cases where unless we know the tree id and session id we > can't figure out which stats (e.g. number of SMB3.1.1 requests by type, > the total time they take, which is slowest, how many fail etc.) apply to > which mount. > > Add an ioctl to return tid, session id, tree connect count and tcon flags. > > -- > Thanks, > > Steve
On Fri, Nov 10, 2023 at 8:21 AM Steve French <smfrench@gmail.com> wrote: > > Updated patch to remove dumping of flags (tcon->Flags was already > supposed to be dumped via > the other ioctl (CIFS_IOC_GET_MNT_INFO) but it had a minor bug - will > send followon patch for that) > > > On Thu, Nov 9, 2023 at 3:51 PM Steve French <smfrench@gmail.com> wrote: > > > > [PATCH] smb3: allow debugging session and tcon info to improve stats > > analysis and debugging > > > > When multiple mounts are to the same share from the same client it was not > > possible to determine which section of /proc/fs/cifs/Stats (and DebugData) > > correspond to that mount. In some recent examples this turned out to be > > a significant problem when trying to analyze performance problems - since > > there are many cases where unless we know the tree id and session id we > > can't figure out which stats (e.g. number of SMB3.1.1 requests by type, > > the total time they take, which is slowest, how many fail etc.) apply to > > which mount. > > > > Add an ioctl to return tid, session id, tree connect count and tcon flags. > > > > -- > > Thanks, > > > > Steve > > > > -- > Thanks, > > Steve IMO, tc_count is not necessary here. We should keep this ioctl very specific to this use case. Moreover, DebugData already prints tc_count.
Fixed one minor bug (missing cifs_put_tlink call to free reference on tlink) and updated cifs-2.6.git for-next See attached (updated patch) On Thu, Nov 9, 2023 at 8:51 PM Steve French <smfrench@gmail.com> wrote: > > Updated patch to remove dumping of flags (tcon->Flags was already > supposed to be dumped via > the other ioctl (CIFS_IOC_GET_MNT_INFO) but it had a minor bug - will > send followon patch for that) > > > On Thu, Nov 9, 2023 at 3:51 PM Steve French <smfrench@gmail.com> wrote: > > > > [PATCH] smb3: allow debugging session and tcon info to improve stats > > analysis and debugging > > > > When multiple mounts are to the same share from the same client it was not > > possible to determine which section of /proc/fs/cifs/Stats (and DebugData) > > correspond to that mount. In some recent examples this turned out to be > > a significant problem when trying to analyze performance problems - since > > there are many cases where unless we know the tree id and session id we > > can't figure out which stats (e.g. number of SMB3.1.1 requests by type, > > the total time they take, which is slowest, how many fail etc.) apply to > > which mount. > > > > Add an ioctl to return tid, session id, tree connect count and tcon flags. > > > > -- > > Thanks, > > > > Steve > > > > -- > Thanks, > > Steve -- Thanks, Steve
Attached is a sample program (that uses the new cifs.ko IOCTL) to dump the tree id for a mount to make it easier to look at traces, wireshark, /proc/fs/cifs/Stats, /proc/fs/cifs/DebugData if you have more than one mount (would be useful to add something similar to debugging tools and/or smb-info or something new in cifs-utils). e.g. # ./get-tcon-inf /mnt2 ioctl completed. tid 0x47b3d0e2 session id: 0xf6cde60a # cat /proc/fs/cifs/DebugData | grep "tid: 0x47b3d0e2" -C3 2) \\localhost\test Mounts: 1 DevInfo: 0x20 Attributes: 0x801007f PathComponentMax: 255 Status: 1 type: DISK Serial Number: 0xaab31952 Share Capabilities: None Aligned, Partition Aligned, Share Flags: 0x0 tid: 0x47b3d0e2 Optimal sector size: 0x200 Maximal Access: 0x1f01ff
From 54796a555a55c40ff61b14f574a139c912cffded Mon Sep 17 00:00:00 2001 From: Steve French <stfrench@microsoft.com> Date: Thu, 9 Nov 2023 15:28:12 -0600 Subject: [PATCH] smb3: allow debugging session and tcon info to improve stats analysis and debugging When multiple mounts are to the same share from the same client it was not possible to determine which section of /proc/fs/cifs/Stats (and DebugData) correspond to that mount. In some recent examples this turned out to be a significant problem when trying to analyze performance problems - since there are many cases where unless we know the tree id and session id we can't figure out which stats (e.g. number of SMB3.1.1 requests by type, the total time they take, which is slowest, how many fail etc.) apply to which mount. Add an ioctl to return tid, session id, tree connect count and tcon flags. Signed-off-by: Steve French <stfrench@microsoft.com> --- fs/smb/client/cifs_ioctl.h | 8 ++++++++ fs/smb/client/ioctl.c | 26 ++++++++++++++++++++++++++ 2 files changed, 34 insertions(+) diff --git a/fs/smb/client/cifs_ioctl.h b/fs/smb/client/cifs_ioctl.h index 332588e77c31..2eb0a747b6c3 100644 --- a/fs/smb/client/cifs_ioctl.h +++ b/fs/smb/client/cifs_ioctl.h @@ -26,6 +26,13 @@ struct smb_mnt_fs_info { __u64 cifs_posix_caps; } __packed; +struct smb_mnt_tcon_info { + __u32 tid; + __u64 session_id; + int tc_count; + __u16 flags; +} __packed; + struct smb_snapshot_array { __u32 number_of_snapshots; __u32 number_of_snapshots_returned; @@ -108,6 +115,7 @@ struct smb3_notify_info { #define CIFS_IOC_NOTIFY _IOW(CIFS_IOCTL_MAGIC, 9, struct smb3_notify) #define CIFS_DUMP_FULL_KEY _IOWR(CIFS_IOCTL_MAGIC, 10, struct smb3_full_key_debug_info) #define CIFS_IOC_NOTIFY_INFO _IOWR(CIFS_IOCTL_MAGIC, 11, struct smb3_notify_info) +#define CIFS_IOC_GET_TCON_INFO _IOR(CIFS_IOCTL_MAGIC, 12, struct smb_mnt_tcon_info) #define CIFS_IOC_SHUTDOWN _IOR('X', 125, __u32) /* diff --git a/fs/smb/client/ioctl.c b/fs/smb/client/ioctl.c index f7160003e0ed..8000433407df 100644 --- a/fs/smb/client/ioctl.c +++ b/fs/smb/client/ioctl.c @@ -117,6 +117,22 @@ static long cifs_ioctl_copychunk(unsigned int xid, struct file *dst_file, return rc; } +static long smb_mnt_get_tcon_info(struct cifs_tcon *tcon, void __user *arg) +{ + int rc = 0; + struct smb_mnt_tcon_info tcon_inf; + + tcon_inf.tid = tcon->tid; + tcon_inf.session_id = tcon->ses->Suid; + tcon_inf.tc_count = tcon->tc_count; + tcon_inf.flags = tcon->Flags; + + if (copy_to_user(arg, &tcon_inf, sizeof(struct smb_mnt_tcon_info))) + rc = -EFAULT; + + return rc; +} + static long smb_mnt_get_fsinfo(unsigned int xid, struct cifs_tcon *tcon, void __user *arg) { @@ -414,6 +430,16 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg) tcon = tlink_tcon(pSMBFile->tlink); rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg); break; + case CIFS_IOC_GET_TCON_INFO: + cifs_sb = CIFS_SB(inode->i_sb); + tlink = cifs_sb_tlink(cifs_sb); + if (IS_ERR(tlink)) { + rc = PTR_ERR(tlink); + break; + } + tcon = tlink_tcon(tlink); + rc = smb_mnt_get_tcon_info(tcon, (void __user *)arg); + break; case CIFS_ENUMERATE_SNAPSHOTS: if (pSMBFile == NULL) break; -- 2.39.2