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authorAndres Salomon <dilinger@queued.net>2011-10-17 03:15:16 +0200
committerArtem Bityutskiy <artem.bityutskiy@intel.com>2011-10-19 16:22:20 +0200
commit92abc475d8de1c29373f6d96ed63d8ecaa199d25 (patch)
tree44f4d9d04fd04ccee9877e28d8fff5e472bba7d2 /fs/jffs2/compr.c
parentmtd: nand: initialize ops.mode (diff)
downloadlinux-92abc475d8de1c29373f6d96ed63d8ecaa199d25.tar.xz
linux-92abc475d8de1c29373f6d96ed63d8ecaa199d25.zip
jffs2: implement mount option parsing and compression overriding
Currently jffs2 has compile-time constants (and .config options) controlling whether or not the various compression/decompression drivers are built in and enabled. This is fine for embedded systems, but it clashes with distribution kernels. Distro kernels tend to turn on everything; this causes OpenFirmware to fall over, as it understands ZLIB-compressed inodes. Booting a kernel that has LZO compression enabled, writing to the boot partition, and then rebooting causes OFW to fail to read the kernel from the filesystem. This is because LZO compression has priority when writing new data to jffs2, if LZO is enabled. This patch adds mount option parsing, and a single supported option ("compr=none"). This adds the flexibility of being able to specify which compressor overrides on a per-superblock basis. For now, we can simply disable compression; additional flexibility coming soon. v2: kill some printks, and implement show_options as suggested by Artem Bityutskiy. Signed-off-by: Andres Salomon <dilinger@queued.net> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@intel.com>
Diffstat (limited to 'fs/jffs2/compr.c')
-rw-r--r--fs/jffs2/compr.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/fs/jffs2/compr.c b/fs/jffs2/compr.c
index de4247021d25..97bc74db2c96 100644
--- a/fs/jffs2/compr.c
+++ b/fs/jffs2/compr.c
@@ -76,13 +76,18 @@ uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
uint32_t *datalen, uint32_t *cdatalen)
{
int ret = JFFS2_COMPR_NONE;
- int compr_ret;
+ int mode, compr_ret;
struct jffs2_compressor *this, *best=NULL;
unsigned char *output_buf = NULL, *tmp_buf;
uint32_t orig_slen, orig_dlen;
uint32_t best_slen=0, best_dlen=0;
- switch (jffs2_compression_mode) {
+ if (c->mount_opts.override_compr)
+ mode = c->mount_opts.compr;
+ else
+ mode = jffs2_compression_mode;
+
+ switch (mode) {
case JFFS2_COMPR_MODE_NONE:
break;
case JFFS2_COMPR_MODE_PRIORITY: