linux-toradex.git/fs/gfs2/rgrp.c, branch v4.2.4

GFS2: Don't brelse rgrp buffer_heads every allocation

2015-06-19T12:40:22+00:00

This patch allows the block allocation code to retain the buffers
for the resource groups so they don't need to be re-read from buffer
cache with every request. This is a performance improvement that's
especially noticeable when resource groups are very large. For
example, with 2GB resource groups and 4K blocks, there can be 33
blocks for every resource group. This patch allows those 33 buffers
to be kept around and not read in and thrown away with every
operation. The buffers are released when the resource group is
either synced or invalidated.

Signed-off-by: Bob Peterson 
Reviewed-by: Steven Whitehouse 
Reviewed-by: Benjamin Marzinski

gfs2: fix shadow warning in gfs2_rbm_find()

2015-05-18T20:23:03+00:00

bi was already declared and initialized globally in gfs2_rbm_find()

Signed-off-by: Fabian Frederick 
Signed-off-by: Bob Peterson

gfs2: handle NULL rgd in set_rgrp_preferences

2015-05-05T16:26:04+00:00

The function set_rgrp_preferences() does not handle the (rarely
returned) NULL value from gfs2_rgrpd_get_next() and this patch
fixes that.

The fs image in question is only 150MB in size which allows for
only 1 rgrp to be created. The in-memory rb tree has only 1 node
and when gfs2_rgrpd_get_next() is called on this sole rgrp, it
returns NULL. (Default behavior is to wrap around the rb tree and
return the first node to give the illusion of a circular linked
list. In the case of only 1 rgrp, we can't have
gfs2_rgrpd_get_next() return the same rgrp (first, last, next all
point to the same rgrp)... that would cause unintended consequences
and infinite loops.)

Signed-off-by: Abhi Das 
Signed-off-by: Bob Peterson

GFS2: Average in only non-zero round-trip times for congestion stats

2015-04-24T12:57:37+00:00

This patch changes function gfs2_rgrp_congested so that it only factors
in non-zero values into its average round trip time. If the round-trip
time is zero for a particular cpu, that cpu has obviously never dealt
with bouncing the resource group in question, so factoring in a zero
value will only skew the numbers. It also fixes a compile error on
some arches related to division.

Signed-off-by: Bob Peterson 
Acked-by: Steven Whitehouse

GFS2: Use average srttb value in congestion calculations

2015-04-24T12:57:08+00:00

This patch changes function gfs2_rgrp_congested so that it uses an
average srttb (smoothed round trip time for blocking rgrp glocks)
rather than the CPU-specific value. If we use the CPU-specific value
it can incorrectly report no contention when there really is contention
due to the glock processing occurring on a different CPU.

Signed-off-by: Bob Peterson 
Acked-by: Steven Whitehouse

gfs2: allow quota_check and inplace_reserve to return available blocks

2015-03-18T17:47:10+00:00

struct gfs2_alloc_parms is passed to gfs2_quota_check() and
gfs2_inplace_reserve() with ap->target containing the number of
blocks being requested for allocation in the current operation.

We add a new field to struct gfs2_alloc_parms called 'allowed'.
gfs2_quota_check() and gfs2_inplace_reserve() return the max
blocks allowed by quota and the max blocks allowed by the chosen
rgrp respectively in 'allowed'.

A new field 'min_target', when non-zero, tells gfs2_quota_check()
and gfs2_inplace_reserve() to not return -EDQUOT/-ENOSPC when
there are atleast 'min_target' blocks allowable/available. The
assumption is that the caller is ok with just 'min_target' blocks
and will likely proceed with allocating them.

Signed-off-by: Abhi Das 
Signed-off-by: Bob Peterson 
Acked-by: Steven Whitehouse

GFS2: If we use up our block reservation, request more next time

2014-11-03T19:26:54+00:00

If we run out of blocks for a given multi-block allocation, we obviously
did not reserve enough. We should reserve more blocks for the next
reservation to reduce fragmentation. This patch increases the size hint
for reservations when they run out.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: Set of distributed preferences for rgrps

2014-11-03T19:24:49+00:00

This patch tries to use the journal numbers to evenly distribute
which node prefers which resource group for block allocations. This
is to help performance.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: Use gfs2_rbm_incr in rgblk_free

2014-10-03T13:40:10+00:00

This patch speeds up GFS2 unlink operations by using function
gfs2_rbm_incr rather than continuously calculating the rbm.

Signed-off-by: Bob Peterson 
Signed-off-by: Steven Whitehouse

GFS2: fix bad inode i_goal values during block allocation

2014-09-19T09:45:18+00:00

This patch checks if i_goal is either zero or if doesn't exist
within any rgrp (i.e gfs2_blk2rgrpd() returns NULL). If so, it
assigns the ip->i_no_addr block as the i_goal.

There are two scenarios where a bad i_goal can result in a
-EBADSLT error.

1. Attempting to allocate to an existing inode:
Control reaches gfs2_inplace_reserve() and ip->i_goal is bad.
We need to fix i_goal here.

2. A new inode is created in a directory whose i_goal is hosed:
In this case, the parent dir's i_goal is copied onto the new
inode. Since the new inode is not yet created, the ip->i_no_addr
field is invalid and so, the fix in gfs2_inplace_reserve() as per
1) won't work in this scenario. We need to catch and fix it sooner
in the parent dir itself (gfs2_create_inode()), before it is
copied to the new inode.

Signed-off-by: Abhi Das 
Signed-off-by: Steven Whitehouse