Revision e6da7c9fed111ba1243297ee6eda8e24ae11c384 authored by Eric Sandeen on 23 May 2009, 19:30:12 UTC, committed by Felix Blyakher on 02 June 2009, 03:59:38 UTC
In the case where growing a filesystem would leave the last AG
too small, the fixup code has an overflow in the calculation
of the new size with one fewer ag, because "nagcount" is a 32
bit number.  If the new filesystem has > 2^32 blocks in it
this causes a problem resulting in an EINVAL return from growfs:

 # xfs_io -f -c "truncate 19998630180864" fsfile
 # mkfs.xfs -f -bsize=4096 -dagsize=76288719b,size=3905982455b fsfile
 # mount -o loop fsfile /mnt
 # xfs_growfs /mnt

meta-data=/dev/loop0             isize=256    agcount=52,
agsize=76288719 blks
         =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=3905982455, imaxpct=5
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=32768, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=0
realtime =none                   extsz=4096   blocks=0, rtextents=0
xfs_growfs: XFS_IOC_FSGROWFSDATA xfsctl failed: Invalid argument

Reported-by: richard.ems@cape-horn-eng.com
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
1 parent 1f23920
Raw File
IRQ.txt
What is an IRQ?

An IRQ is an interrupt request from a device.
Currently they can come in over a pin, or over a packet.
Several devices may be connected to the same pin thus
sharing an IRQ.

An IRQ number is a kernel identifier used to talk about a hardware
interrupt source.  Typically this is an index into the global irq_desc
array, but except for what linux/interrupt.h implements the details
are architecture specific.

An IRQ number is an enumeration of the possible interrupt sources on a
machine.  Typically what is enumerated is the number of input pins on
all of the interrupt controller in the system.  In the case of ISA
what is enumerated are the 16 input pins on the two i8259 interrupt
controllers.

Architectures can assign additional meaning to the IRQ numbers, and
are encouraged to in the case  where there is any manual configuration
of the hardware involved.  The ISA IRQs are a classic example of
assigning this kind of additional meaning.
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