glusterfs.git/xlators/mount/fuse/utils, branch v7dev

mount/fuse: expose auto-invalidation as a mount option

2019-02-02T03:07:35+00:00

Auto invalidation is necessary when same (meta)data is shared/access
across multiple mounts. However, if (meta)data is not shared, all
relevant I/O goes through the cache of single mount and hence is
coherent with (meta)data on bricks always. So, fuse-auto-invalidation
can be disabled for this case which gives a huge performance boost for
workloads that write data and then immediately read the data they just
wrote.

From glusterfs --help,


      --auto-invalidation[=BOOL]   controls whether fuse-kernel can
                             auto-invalidate attribute, dentry and page-cache.
                             Disable this only if same files/directories are
                             not accessed across two different mounts
                             concurrently [default: "on"]


Details on how disabling auto-invalidation helped to reduce pgbench
init times can be found at [1]. Time taken for pgbench init of scale
8000 was 8340s. That will be an improvement of 86% (59280s vs 8340s)
with auto-invalidations turned off along with other
optimizations. Just disabling auto-invalidation contributed 56%
improvement by reducing the total time taken by 33260s.

[1] https://www.spinics.net/lists/gluster-devel/msg25907.html

Change-Id: I0ed730dba9064bd9c576ad1800170a21e100e1ce
Signed-off-by: Raghavendra Gowdappa 
updates: bz#1664934

fuse: add --lru-limit option

2018-12-14T17:34:28+00:00

The inode LRU mechanism is moot in fuse xlator (ie. there is no
limit for the LRU list), as fuse inodes are referenced from
kernel context, and thus they can only be dropped on request of
the kernel. This might results in a high number of passive
inodes which are useless for the glusterfs client, causing a
significant memory overhead.

This change tries to remedy this by extending the LRU semantics
and allowing to set a finite limit on the fuse inode LRU.

A brief history of problem:

When gluster's inode table was designed, fuse didn't have any
'invalidate' method, which means, userspace application could
never ask kernel to send a 'forget()' fop, instead had to wait
for kernel to send it based on kernel's parameters. Inode table
remembers the number of times kernel has cached the inode based
on the 'nlookup' parameter. And 'nlookup' field is not used by
no other entry points (like server-protocol, gfapi etc).

Hence the inode_table of fuse module always has to have lru-limit
as '0', which means no limit. GlusterFS always had to keep all
inodes in memory as kernel would have had a reference to it.
Again, the reason for this is, kernel's glusterfs inode reference
was pointer of 'inode_t' structure in glusterfs. As it is a
pointer, we could never free it (to prevent segfault, or memory
corruption).

Solution:

In the inode table, handle the prune case of inodes with 'nlookup'
differently, and call a 'invalidator' method, which in this case is
fuse_invalidate(), and it sends the request to kernel for getting
the forget request.

When the kernel sends the forget, it means, it has dropped all
the reference to the inode, and it will send the forget with the
'nlookup' parameter too. We just need to make sure to reduce the
'nlookup' value we have when we get forget. That automatically
cause the relevant prune to happen.

Credits: Csaba Henk, Xavier Hernandez, Raghavendra Gowdappa, Nithya B

fixes: bz#1560969
Change-Id: Ifee0737b23b12b1426c224ec5b8f591f487d83a2
Signed-off-by: Amar Tumballi

fuse: diagnostic FLUSH interrupt

2018-11-06T04:21:57+00:00

We add dummy interrupt handling for the FLUSH
fuse message. It can be enabled by the
"--fuse-flush-handle-interrupt" hidden command line
option, or "-ofuse-flush-handle-interrupt=yes"
mount option.

It serves no other than diagnostic & demonstational
purposes -- to exercise the interrupt handling framework
a bit and to give an usage example.

Documentation is also provided that showcases interrupt
handling via FLUSH.

Change-Id: I522f1e798501d06b74ac3592a5f73c1ab0590c60
updates: #465
Signed-off-by: Csaba Henk

mount.glusterfs: A more explicit check to avoid identical mounts

2018-10-24T10:18:58+00:00

Change check condition from
"[[:space:]+]${mount_point}[[:space:]+]fuse" to
"[[:space:]+]${mount_point}[[:space:]+]fuse.glusterfs". Fix false
postive check result for mount points of other FUSEes, such as "fuse.sshfs".

Change-Id: I13898b50a651a8f5ecc3a94d01b3b5de37ec4cbc
fixes: bz#1640026
Signed-off-by: Han Han

fuse: prevent error message "can't shift that many"

2018-10-01T04:26:45+00:00

On systems where /bin/sh is not Bash, running plain mount.glusterfs
gives the unhelpful error "can't shift that many".

The argument parsing can be a little improved. Adding a check for the
number of arguments, minimal two (Gluster ip:/volume, and mountpoint),
but possibly more (-o, -v etc.).

With the additional check, running 'mount.glusterfs -h' now shows the
following messags:

    Usage: /sbin/mount.glusterfs :  -o
    Options:
    man 8 mount.glusterfs
    To display the version number of the mount helper: /sbin/mount.glusterfs -V

Change-Id: I50e3ade0c6217fab4155f35ad8cb35d99d52e133
Fixes: bz#1564890
Reported-by: Alexander Zimmermann 
Signed-off-by: Niels de Vos

fuse: avoid using the which command

2018-06-21T05:44:26+00:00

In mount.glusterfs avoid using the which tool as it may not exist
on minimal system installs. Use the "command -v" builtin as
it is expected to be more portable.
Remove a extra semicolon while we're at it.

Change-Id: Ib682ed4955d5bad1beb94b65d10f4c44e9490767
fixes: bz#1593351
Signed-off-by: John Mulligan

mount,fuse: make fuse dumping available as mount option

2018-05-04T17:42:12+00:00

Updates: bz#1193929
Change-Id: I4dd4d0e607f89650ebb74b893b911b554472826d
Signed-off-by: Csaba Henk

fuse: add support for kernel writeback cache

2018-05-04T17:42:12+00:00

- Added kernel-writeback-cache command line and xlator
  option for requesting utilisation of the writeback
  cache of the kernel in FUSE_INIT (see [1]).
- Added attr-times-granularity command line and xlator
  option via which granularity of the {a,m,c}time in
  stat (attr) data that we support can be indicated to
  kernel. This is a means to avoid divergence of the
  attr times between kernel and userspace that could
  occur with writeback-cache, while still maintaining
  maximum time precision the FUSE server is capable of
  (see [2]).
- Handling FATTR_CTIME flag in FUSE_SETATTR that
  indicates presence of ctime in setattr payload.
  Currently we cannot associate arbitrary ctimes to
  files on backend, so we just touch them to update
  their ctimes to current time. Having ctimes in setattr
  payload is also a side effect of writeback cache
  (see [3] and [4]).

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4d99ff8,
     "fuse: Turn writeback cache on"
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e27c9d3,
     "fuse: fuse: add time_gran to INIT_OUT"
[3]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1e18bda,
     "fuse: add .write_inode"
[4]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ab9e13f,
     "fuse: allow ctime flushing to userspace"

Updates: #435
Change-Id: Id174c8e0c815c4456c35f8c53e41a6a507d91855
Signed-off-by: Csaba Henk

mount/fuse: Add support for multi-threaded fuse readers

2018-04-02T06:10:30+00:00

Usage: Use 'reader-thread-count=' as command line option to
set the thread count at the time of mounting the volume.

Next task is to make these threads auto-scale based on the load,
instead of having the user remount the volume everytime to change
the thread count.

Updates #412

Change-Id: I94aa1505e5ae6a133683d473e0e4e0edd139b76b
Signed-off-by: Krutika Dhananjay

gfproxyd: Let glusterd manage gfproxy daemon

2017-10-18T14:15:05+00:00

Updates: #242
BUG: 1428063
Change-Id: Iaaf2edf99b2ecc75f6d30762c752a6d445c1c826
Signed-off-by: Poornima G