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authorLinus Torvalds <torvalds@linux-foundation.org>2015-09-07 13:28:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-09-07 13:28:32 -0700
commit77a78806c7df8d414c33031a1ca5121876910c4f (patch)
tree8206a5e1e1f3619bdfb882386c3b6a808f171277 /fs/xfs/libxfs/xfs_bit.c
parent7d9071a095023cd1db8fa18fa0d648dc1a5210e0 (diff)
parent5d54b8cdeaf4679c51a510dea3f8921992d0b064 (diff)
Merge tag 'xfs-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pull xfs updates from Dave Chinner: "There isn't a whole lot to this update - it's mostly bug fixes and they are spread pretty much all over XFS. There are some corruption fixes, some fixes for log recovery, some fixes that prevent unount from hanging, a lockdep annotation rework for inode locking to prevent false positives and the usual random bunch of cleanups and minor improvements. Deatils: - large rework of EFI/EFD lifecycle handling to fix log recovery corruption issues, crashes and unmount hangs - separate metadata UUID on disk to enable changing boot label UUID for v5 filesystems - fixes for gcc miscompilation on certain platforms and optimisation levels - remote attribute allocation and recovery corruption fixes - inode lockdep annotation rework to fix bugs with too many subclasses - directory inode locking changes to prevent lockdep false positives - a handful of minor corruption fixes - various other small cleanups and bug fixes" * tag 'xfs-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (42 commits) xfs: fix error gotos in xfs_setattr_nonsize xfs: add mssing inode cache attempts counter increment xfs: return errors from partial I/O failures to files libxfs: bad magic number should set da block buffer error xfs: fix non-debug build warnings xfs: collapse allocsize and biosize mount option handling xfs: Fix file type directory corruption for btree directories xfs: lockdep annotations throw warnings on non-debug builds xfs: Fix uninitialized return value in xfs_alloc_fix_freelist() xfs: inode lockdep annotations broke non-lockdep build xfs: flush entire file on dio read/write to cached file xfs: Fix xfs_attr_leafblock definition libxfs: readahead of dir3 data blocks should use the read verifier xfs: stop holding ILOCK over filldir callbacks xfs: clean up inode lockdep annotations xfs: swap leaf buffer into path struct atomically during path shift xfs: relocate sparse inode mount warning xfs: dquots should be stamped with sb_meta_uuid xfs: log recovery needs to validate against sb_meta_uuid xfs: growfs not aware of sb_meta_uuid ...
Diffstat (limited to 'fs/xfs/libxfs/xfs_bit.c')
-rw-r--r--fs/xfs/libxfs/xfs_bit.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bit.c b/fs/xfs/libxfs/xfs_bit.c
new file mode 100644
index 000000000000..0e8885a59646
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_bit.c
@@ -0,0 +1,118 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "xfs.h"
+#include "xfs_log_format.h"
+#include "xfs_bit.h"
+
+/*
+ * XFS bit manipulation routines, used in non-realtime code.
+ */
+
+/*
+ * Return whether bitmap is empty.
+ * Size is number of words in the bitmap, which is padded to word boundary
+ * Returns 1 for empty, 0 for non-empty.
+ */
+int
+xfs_bitmap_empty(uint *map, uint size)
+{
+ uint i;
+ uint ret = 0;
+
+ for (i = 0; i < size; i++) {
+ ret |= map[i];
+ }
+
+ return (ret == 0);
+}
+
+/*
+ * Count the number of contiguous bits set in the bitmap starting with bit
+ * start_bit. Size is the size of the bitmap in words.
+ */
+int
+xfs_contig_bits(uint *map, uint size, uint start_bit)
+{
+ uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
+ uint result = 0;
+ uint tmp;
+
+ size <<= BIT_TO_WORD_SHIFT;
+
+ ASSERT(start_bit < size);
+ size -= start_bit & ~(NBWORD - 1);
+ start_bit &= (NBWORD - 1);
+ if (start_bit) {
+ tmp = *p++;
+ /* set to one first offset bits prior to start */
+ tmp |= (~0U >> (NBWORD-start_bit));
+ if (tmp != ~0U)
+ goto found;
+ result += NBWORD;
+ size -= NBWORD;
+ }
+ while (size) {
+ if ((tmp = *p++) != ~0U)
+ goto found;
+ result += NBWORD;
+ size -= NBWORD;
+ }
+ return result - start_bit;
+found:
+ return result + ffz(tmp) - start_bit;
+}
+
+/*
+ * This takes the bit number to start looking from and
+ * returns the next set bit from there. It returns -1
+ * if there are no more bits set or the start bit is
+ * beyond the end of the bitmap.
+ *
+ * Size is the number of words, not bytes, in the bitmap.
+ */
+int xfs_next_bit(uint *map, uint size, uint start_bit)
+{
+ uint * p = ((unsigned int *) map) + (start_bit >> BIT_TO_WORD_SHIFT);
+ uint result = start_bit & ~(NBWORD - 1);
+ uint tmp;
+
+ size <<= BIT_TO_WORD_SHIFT;
+
+ if (start_bit >= size)
+ return -1;
+ size -= result;
+ start_bit &= (NBWORD - 1);
+ if (start_bit) {
+ tmp = *p++;
+ /* set to zero first offset bits prior to start */
+ tmp &= (~0U << start_bit);
+ if (tmp != 0U)
+ goto found;
+ result += NBWORD;
+ size -= NBWORD;
+ }
+ while (size) {
+ if ((tmp = *p++) != 0U)
+ goto found;
+ result += NBWORD;
+ size -= NBWORD;
+ }
+ return -1;
+found:
+ return result + ffs(tmp) - 1;
+}