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authorPhillip Lougher <phillip@lougher.demon.co.uk>2011-02-28 02:45:42 +0100
committerPhillip Lougher <phillip@lougher.demon.co.uk>2011-02-28 19:21:59 +0100
commitb7fc0ff09d24b372dc04b0c02b80659c0a66fdfe (patch)
tree9cd9a94c3b07ef8064e1952a376d964776aa4571 /fs/squashfs/decompressor.c
parentLinux 2.6.38-rc4 (diff)
downloadlinux-b7fc0ff09d24b372dc04b0c02b80659c0a66fdfe.tar.xz
linux-b7fc0ff09d24b372dc04b0c02b80659c0a66fdfe.zip
Squashfs: extend decompressor framework to handle compression options
Extend decompressor framework to handle compression options stored in the filesystem. These options can be used by the relevant decompressor at initialisation time to over-ride defaults. The presence of compression options in the filesystem is indicated by the COMP_OPT filesystem flag. If present the data is read from the filesystem and passed to the decompressor init function. The decompressor init function signature has been extended to take this data. Also update the init function signature in the glib, lzo and xz decompressor wrappers. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Diffstat (limited to 'fs/squashfs/decompressor.c')
-rw-r--r--fs/squashfs/decompressor.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/fs/squashfs/decompressor.c b/fs/squashfs/decompressor.c
index a5940e54c4dd..e921bd213738 100644
--- a/fs/squashfs/decompressor.c
+++ b/fs/squashfs/decompressor.c
@@ -23,6 +23,7 @@
#include <linux/types.h>
#include <linux/mutex.h>
+#include <linux/slab.h>
#include <linux/buffer_head.h>
#include "squashfs_fs.h"
@@ -74,3 +75,36 @@ const struct squashfs_decompressor *squashfs_lookup_decompressor(int id)
return decompressor[i];
}
+
+
+void *squashfs_decompressor_init(struct super_block *sb, unsigned short flags)
+{
+ struct squashfs_sb_info *msblk = sb->s_fs_info;
+ void *strm, *buffer = NULL;
+ int length = 0;
+
+ /*
+ * Read decompressor specific options from file system if present
+ */
+ if (SQUASHFS_COMP_OPTS(flags)) {
+ buffer = kmalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
+ if (buffer == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ length = squashfs_read_data(sb, &buffer,
+ sizeof(struct squashfs_super_block), 0, NULL,
+ PAGE_CACHE_SIZE, 1);
+
+ if (length < 0) {
+ strm = ERR_PTR(length);
+ goto finished;
+ }
+ }
+
+ strm = msblk->decompressor->init(msblk, buffer, length);
+
+finished:
+ kfree(buffer);
+
+ return strm;
+}