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authorIngo Molnar <mingo@kernel.org>2014-05-07 13:15:46 +0200
committerIngo Molnar <mingo@kernel.org>2014-05-07 13:15:46 +0200
commit2fe5de9ce7d57498abc14b375cad2fcf8c3ee6cc (patch)
tree9478e8cf470c1d5bdb2d89b57a7e35919ab95e72 /include/uapi/linux/falloc.h
parent08f8aeb55d7727d644dbbbbfb798fe937d47751d (diff)
parent2b4cfe64dee0d84506b951d81bf55d9891744d25 (diff)
Merge branch 'sched/urgent' into sched/core, to avoid conflicts
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/uapi/linux/falloc.h')
-rw-r--r--include/uapi/linux/falloc.h35
1 files changed, 35 insertions, 0 deletions
diff --git a/include/uapi/linux/falloc.h b/include/uapi/linux/falloc.h
index 990c4ccf8b61..d1197ae3723c 100644
--- a/include/uapi/linux/falloc.h
+++ b/include/uapi/linux/falloc.h
@@ -5,5 +5,40 @@
#define FALLOC_FL_PUNCH_HOLE 0x02 /* de-allocates range */
#define FALLOC_FL_NO_HIDE_STALE 0x04 /* reserved codepoint */
+/*
+ * FALLOC_FL_COLLAPSE_RANGE is used to remove a range of a file
+ * without leaving a hole in the file. The contents of the file beyond
+ * the range being removed is appended to the start offset of the range
+ * being removed (i.e. the hole that was punched is "collapsed"),
+ * resulting in a file layout that looks like the range that was
+ * removed never existed. As such collapsing a range of a file changes
+ * the size of the file, reducing it by the same length of the range
+ * that has been removed by the operation.
+ *
+ * Different filesystems may implement different limitations on the
+ * granularity of the operation. Most will limit operations to
+ * filesystem block size boundaries, but this boundary may be larger or
+ * smaller depending on the filesystem and/or the configuration of the
+ * filesystem or file.
+ *
+ * Attempting to collapse a range that crosses the end of the file is
+ * considered an illegal operation - just use ftruncate(2) if you need
+ * to collapse a range that crosses EOF.
+ */
+#define FALLOC_FL_COLLAPSE_RANGE 0x08
+
+/*
+ * FALLOC_FL_ZERO_RANGE is used to convert a range of file to zeros preferably
+ * without issuing data IO. Blocks should be preallocated for the regions that
+ * span holes in the file, and the entire range is preferable converted to
+ * unwritten extents - even though file system may choose to zero out the
+ * extent or do whatever which will result in reading zeros from the range
+ * while the range remains allocated for the file.
+ *
+ * This can be also used to preallocate blocks past EOF in the same way as
+ * with fallocate. Flag FALLOC_FL_KEEP_SIZE should cause the inode
+ * size to remain the same.
+ */
+#define FALLOC_FL_ZERO_RANGE 0x10
#endif /* _UAPI_FALLOC_H_ */