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For PR 2164 - RFS File System - fix bitmap_create_search loop bug

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This is for the RFS file system. There is a bug in the
rtems_rfs_bitmap_create_search loop. It is supposed to iterate
over the range of bits in a search element ( usually 32 bits ),
so it should loop through bits 0 through 31. Instead it loops
through 0 - 32, causing some blocks not to be allocated. As in
PR 2163, this depends on the block size and number of blocks in
a file system. Block sizes and group sizes that are powers of 2
seem to work fine ( 512 byte blocks, 4096 block groups, etc ).
When the block sizes are not powers of 2, then this loop error
causes some of the blocks at the end of a group to be skipped,
preventing 100% of the blocks from being used. A simple test
for this and PR2163 is to create a RAM disk with block size
3900 and at least 1 full group ( 31200 blocks ). A file system
with these sizes will not be able to allocate 100% of the blocks.
This commit is contained in:
Alan Cudmore
2013-12-19 11:07:47 +11:00
committed by Chris Johns
parent 9b48dc67ed
commit a9619f3cb6
1 changed files with 2 additions and 1 deletions
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cpukit/libfs/src/rfs/rtems-rfs-bitmaps.c
+2 -1
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@@ -599,7 +599,8 @@ rtems_rfs_bitmap_create_search (rtems_rfs_bitmap_control* control)
size -= available;
if (bit == rtems_rfs_bitmap_element_bits ())
/* Iterate from 0 to 1 less than the number of bits in an element */
if (bit == (rtems_rfs_bitmap_element_bits () - 1))
{
bit = 0;
search_map++;