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,

<snip>
      --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"]
</snip>

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 <rgowdapp@redhat.com>
updates: bz#1664934

design reference: https://review.gluster.org/#/c/glusterfs-specs/+/21925/

This patch adds the lock preempt support.

Note: The current model stores lock enforcement information as separate
xattr on disk. There is another effort going in parallel to store this
in stat(x) of the file. This patch is self sufficient to add fencing
support. Based on the availability of the stat(x) support either I will
rebase this patch or we can modify the necessary bits post merging this
patch.

Change-Id: If4a42f3e0afaee1f66cdb0360ad4e0c005b5b017
updates: #466
Signed-off-by: Susant Palai <spalai@redhat.com>

With brick mux, the number of threads increases as the number of
bricks increases. As an initiative to reduce the number of
threads in brick mux scenario, replacing janitor thread to use
synctask infra.

Now close() and closedir() handle by separate janitor
thread which is linked with glusterfs_ctx.

Updates #475
Change-Id: I0c4aaf728125ab7264442fde59f3d08542785f73
Signed-off-by: Poornima G <pgurusid@redhat.com>

Currently mem-pool implementation provides api to get from the
mem pool based on the struct type. This is to retain api
compatibility with the old implementation of mem pool. Internally
in the mem pool structure there is a mapping from struct to size
based pools.

In this patch, we are adding new APIs to fetch memory from mem pool,
given a size.

Change-Id: Ib220ee45ebd134a7be8f6482db5a592dbb7b9211
Updates: #325
Signed-off-by: Poornima G <pgurusid@redhat.com>

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 <amarts@redhat.com>

libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation <> in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR <srangana@redhat.com>