patch-2.4.19 linux-2.4.19/fs/cramfs/README
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- Lines: 55
- Date:
Fri Aug 2 17:39:45 2002
- Orig file:
linux-2.4.18/fs/cramfs/README
- Orig date:
Thu Jul 19 16:14:53 2001
diff -urN linux-2.4.18/fs/cramfs/README linux-2.4.19/fs/cramfs/README
@@ -6,8 +6,8 @@
swapped around (though it does care that directory entries (inodes) in
a given directory are contiguous, as this is used by readdir).
-All data is in host-endian format; neither mkcramfs nor the kernel
-ever do swabbing. (See section `Block Size' below.)
+All data is currently in host-endian format; neither mkcramfs nor the
+kernel ever do swabbing. (See section `Block Size' below.)
<filesystem>:
<superblock>
@@ -29,6 +29,10 @@
lines); put another way, the same order as `find -type d -exec
ls -AU1 {} \;'.
+Beginning in 2.4.7, directory entries are sorted. This optimization
+allows cramfs_lookup to return more quickly when a filename does not
+exist, speeds up user-space directory sorts, etc.
+
<data>:
One <file_data> for each file that's either a symlink or a
regular file of non-zero st_size.
@@ -63,17 +67,15 @@
This kernel supports cramfs holes (i.e. [efficient representation of]
blocks in uncompressed data consisting entirely of NUL bytes), but by
default mkcramfs doesn't test for & create holes, since cramfs in
-kernels up to at least 2.3.39 didn't support holes. Compile mkcramfs
-with -DDO_HOLES if you want it to create files that can have holes in
-them.
+kernels up to at least 2.3.39 didn't support holes. Run mkcramfs
+with -z if you want it to create files that can have holes in them.
Tools
-----
-If you're hacking on cramfs, you might find useful some tools for
-testing cramfs at <http://cvs.bofh.asn.au/cramfs/>, including a
-rudimentary fsck for cramfs.
+The cramfs user-space tools, including mkcramfs and cramfsck, are
+located at <http://sourceforge.net/projects/cramfs/>.
Future Development
@@ -103,8 +105,8 @@
PAGE_CACHE_SIZE (4096)' to `#include <asm/page.h>'. The disadvantage
is that the generated cramfs cannot always be shared between different
kernels, not even necessarily kernels of the same architecture if
-PAGE_CACHE_SIZE is subject to change between kernel versions.
-
+PAGE_CACHE_SIZE is subject to change between kernel versions
+(currently possible with arm and ia64).
The remaining options try to make cramfs more sharable.
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)