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  1. 24 Oct, 2011 2 commits
  3. 14 Oct, 2011 8 commits
    • Boaz Harrosh's avatar
      ore/exofs: Change ore_check_io API · 4b46c9f5
      Boaz Harrosh authored 
      Current ore_check_io API receives a residual
pointer, to report partial IO. But it is actually
not used, because in a multiple devices IO there
is never a linearity in the IO failure.

On the other hand if every failing device is reported
through a received callback measures can be taken to
handle only failed devices. One at a time.

This will also be needed by the objects-layout-driver
for it's error reporting facility.

Exofs is not currently using the new information and
keeps the old behaviour of failing the complete IO in
case of an error. (No partial completion)

TODO: Use an ore_check_io callback to set_page_error only
the failing pages. And re-dirty write pages.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      4b46c9f5
    • Boaz Harrosh's avatar
      ore/exofs: Define new ore_verify_layout · 5a51c0c7
      Boaz Harrosh authored 
      All users of the ore will need to check if current code
supports the given layout. For example RAID5/6 is not
currently supported.

So move all the checks from exofs/super.c to a new
ore_verify_layout() to be used by ore users.

Note that any new layout should be passed through the
ore_verify_layout() because the ore engine will prepare
and verify some internal members of ore_layout, and
assumes it's called.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      5a51c0c7
    • Boaz Harrosh's avatar
      ore: Support for partial component table · 3bd98568
      Boaz Harrosh authored 
      Users like the objlayout-driver would like to only pass
a partial device table that covers the IO in question.
For example exofs divides the file into raid-group-sized
chunks and only serves group_width number of devices at
a time.

The partiality is communicated by setting
ore_componets->first_dev and the array covers all logical
devices from oc->first_dev upto (oc->first_dev + oc->numdevs)

The ore_comp_dev() API receives a logical device index
and returns the actual present device in the table.
An out-of-range dev_index will BUG.

Logical device index is the theoretical device index as if
all the devices of a file are present. .i.e:
	total_devs = group_width * mirror_p1 * group_count
	0 <= dev_index < total_devs
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      3bd98568
    • Boaz Harrosh's avatar
      ore: Support for short read/writes · bbf9a31b
      Boaz Harrosh authored 
      Memory conditions and max_bio constraints might cause us to
not comply to the full length of the requested IO. Instead of
failing the complete IO we can issue a shorter read/write and
report how much was actually executed in the ios->length
member.

All users must check ios->length at IO_done or upon return of
ore_read/write and re-issue the reminder of the bytes. Because
other wise there is no error returned like before.

This is part of the effort to support the pnfs-obj layout driver.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      bbf9a31b
    • Boaz Harrosh's avatar
      exofs: Support for short read/writes · 154a9300
      Boaz Harrosh authored 
      If at read/write_done the actual IO was shorter then requested,
reported in returned ios->length. It is not an error. The reminder
of the pages should just be unlocked but not marked uptodate or
end_page_writeback. They will be re issued later by the VFS.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      154a9300
    • Boaz Harrosh's avatar
      ore: Remove check for ios->kern_buff in _prepare_for_striping to later · 6851a5e5
      Boaz Harrosh authored 
      Move the check and preparation of the ios->kern_buff case to
later inside _write_mirror().

Since read was never used with ios->kern_buff its support is removed
instead of fixed.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      6851a5e5
    • Boaz Harrosh's avatar
      ore: cleanup: Embed an ore_striping_info inside ore_io_state · 98260754
      Boaz Harrosh authored 
      Now that each ore_io_state covers only a single raid group.
A single striping_info math is needed. Embed one inside
ore_io_state to cache the calculation results and eliminate
an extra call.

Also the outer _prepare_for_striping is removed since it does nothing.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      98260754
    • Boaz Harrosh's avatar
      ore: Only IO one group at a time (API change) · b916c5cd
      Boaz Harrosh authored 
      Usually a single IO is confined to one group of devices
(group_width) and at the boundary of a raid group it can
spill into a second group. Current code would allocate a
full device_table size array at each io_state so it can
comply to requests that span two groups. Needless to say
that is very wasteful, specially when device_table count
can get very large (hundreds even thousands), while a
group_width is usually 8 or 10.

* Change ore API to trim on IO that spans two raid groups.
  The user passes offset+length to ore_get_rw_state, the
  ore might trim on that length if spanning a group boundary.
  The user must check ios->length or ios->nrpages to see
  how much IO will be preformed. It is the responsibility
  of the user to re-issue the reminder of the IO.

* Modify exofs To copy spilled pages on to the next IO.
  This means one last kick is needed after all coalescing
  of pages is done.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      b916c5cd
  5. 04 Oct, 2011 1 commit
    • Boaz Harrosh's avatar
      ore/exofs: Change the type of the devices array (API change) · d866d875
      Boaz Harrosh authored 
      In the pNFS obj-LD the device table at the layout level needs
to point to a device_cache node, where it is possible and likely
that many layouts will point to the same device-nodes.

In Exofs we have a more orderly structure where we have a single
array of devices that repeats twice for a round-robin view of the
device table

This patch moves to a model that can be used by the pNFS obj-LD
where struct ore_components holds an array of ore_dev-pointers.
(ore_dev is newly defined and contains a struct osd_dev *od
 member)

Each pointer in the array of pointers will point to a bigger
user-defined dev_struct. That can be accessed by use of the
container_of macro.

In Exofs an __alloc_dev_table() function allocates the
ore_dev-pointers array as well as an exofs_dev array, in one
allocation and does the addresses dance to set everything pointing
correctly. It still keeps the double allocation trick for the
inodes round-robin view of the table.

The device table is always allocated dynamically, also for the
single device case. So it is unconditionally freed at umount.
Signed-off-by: default avatarBoaz Harrosh <bharrosh@panasas.com>
      d866d875
  7. 03 Oct, 2011 5 commits
  9. 22 Sep, 2011 1 commit
  11. 12 Sep, 2011 9 commits
  13. 11 Sep, 2011 14 commits
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