linux-stable.git/fs/ceph/debugfs.c, branch v6.17

ceph: fix race condition validating r_parent before applying state

2025-09-09T10:57:02+00:00

Add validation to ensure the cached parent directory inode matches the
directory info in MDS replies. This prevents client-side race conditions
where concurrent operations (e.g. rename) cause r_parent to become stale
between request initiation and reply processing, which could lead to
applying state changes to incorrect directory inodes.

[ idryomov: folded a kerneldoc fixup and a follow-up fix from Alex to
  move CEPH_CAP_PIN reference when r_parent is updated:

  When the parent directory lock is not held, req->r_parent can become
  stale and is updated to point to the correct inode.  However, the
  associated CEPH_CAP_PIN reference was not being adjusted.  The
  CEPH_CAP_PIN is a reference on an inode that is tracked for
  accounting purposes.  Moving this pin is important to keep the
  accounting balanced. When the pin was not moved from the old parent
  to the new one, it created two problems: The reference on the old,
  stale parent was never released, causing a reference leak.
  A reference for the new parent was never acquired, creating the risk
  of a reference underflow later in ceph_mdsc_release_request().  This
  patch corrects the logic by releasing the pin from the old parent and
  acquiring it for the new parent when r_parent is switched.  This
  ensures reference accounting stays balanced. ]

Cc: stable@vger.kernel.org
Signed-off-by: Alex Markuze 
Reviewed-by: Viacheslav Dubeyko 
Signed-off-by: Ilya Dryomov

ceph: exchange hardcoded value on NAME_MAX

2025-01-27T15:07:42+00:00

Initially, ceph_fs_debugfs_init() had temporary
name buffer with hardcoded length of 80 symbols.
Then, it was hardcoded again for 100 symbols.
Finally, it makes sense to exchange hardcoded
value on properly defined constant and 255 symbols
should be enough for any name case.

Signed-off-by: Viacheslav Dubeyko 
Reviewed-by: Patrick Donnelly 
Signed-off-by: Ilya Dryomov

ceph: Use str_true_false() helper in status_show()

2024-11-18T16:34:36+00:00

Remove hard-coded strings by using the str_true_false() helper function.

Signed-off-by: Thorsten Blum 
Reviewed-by: Ilya Dryomov 
Signed-off-by: Ilya Dryomov

ceph: print cluster fsid and client global_id in all debug logs

2023-11-03T22:28:33+00:00

Multiple CephFS mounts on a host is increasingly common so
disambiguating messages like this is necessary and will make it easier
to debug issues.

At the same this will improve the debug logs to make them easier to
troubleshooting issues, such as print the ino# instead only printing
the memory addresses of the corresponding inodes and print the dentry
names instead of the corresponding memory addresses for the dentry,etc.

Link: https://tracker.ceph.com/issues/61590
Signed-off-by: Xiubo Li 
Reviewed-by: Patrick Donnelly 
Reviewed-by: Milind Changire 
Signed-off-by: Ilya Dryomov

ceph: pass the mdsc to several helpers

2023-11-03T22:28:33+00:00

We will use the 'mdsc' to get the global_id in the following commits.

Link: https://tracker.ceph.com/issues/61590
Signed-off-by: Xiubo Li 
Reviewed-by: Patrick Donnelly 
Reviewed-by: Milind Changire 
Signed-off-by: Ilya Dryomov

ceph: fix potential use-after-free bug when trimming caps

2023-04-30T10:37:28+00:00

When trimming the caps and just after the 'session->s_cap_lock' is
released in ceph_iterate_session_caps() the cap maybe removed by
another thread, and when using the stale cap memory in the callbacks
it will trigger use-after-free crash.

We need to check the existence of the cap just after the 'ci->i_ceph_lock'
being acquired. And do nothing if it's already removed.

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/43272
Signed-off-by: Xiubo Li 
Reviewed-by: Luís Henriques 
Signed-off-by: Ilya Dryomov

ceph: use tracked average r/w/m latencies to display metrics in debugfs

2022-03-21T12:35:16+00:00

Signed-off-by: Venky Shankar 
Reviewed-by: Xiubo Li 
Signed-off-by: Ilya Dryomov

ceph: add a new metric to keep track of remote object copies

2021-11-08T02:29:52+00:00

This patch adds latency and size metrics for remote object copies
operations ("copyfrom").  For now, these metrics will be available on the
client only, they won't be sent to the MDS.

Signed-off-by: Luís Henriques 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: clean-up metrics data structures to reduce code duplication

2021-11-08T02:29:52+00:00

This patch modifies struct ceph_client_metric so that each metric block
(read, write and metadata) becomes an element in a array.  This allows to
also re-write the helper functions that handle these blocks, making them
simpler and, above all, reduce the amount of copy&paste every time a new
metric is added.

Thus, for each of these metrics there will be a new struct ceph_metric
entry that'll will contain all the sizes and latencies fields (and a lock).
Note however that the metadata metric doesn't really use the size_fields,
and thus this metric won't be shown in the debugfs '../metrics/size' file.

Signed-off-by: Luís Henriques 
Reviewed-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov

ceph: split 'metric' debugfs file into several files

2021-11-08T02:29:52+00:00

Currently, all the metrics are grouped together in a single file, making
it difficult to process this file from scripts.  Furthermore, as new
metrics are added, processing this file will become even more challenging.

This patch turns the 'metric' file into a directory that will contain
several files, one for each metric.

Signed-off-by: Luís Henriques 
Reviewed-by: Xiubo Li 
Reviewed-by: Jeff Layton 
Signed-off-by: Ilya Dryomov