2006-03-02 17:45:58

by Dave Johnson

Subject: [PATCH] Re: cramfs mounts provide corrupted content since 2.6.15

Fix handling of cramfs images created by util-linux containing empty regular
files. Images created by cramfstools 1.x were ok.

Fill out inode contents in cramfs_iget5_set() instead of get_cramfs_inode() to
prevent issues if cramfs_iget5_test() is called with I_LOCK|I_NEW still set.


Signed-off-by: Dave Johnson <[email protected]>

diff -Naur linux-2.6.15.4.orig/fs/cramfs/inode.c linux-2.6.15.4/fs/cramfs/inode.c
--- linux-2.6.15.4.orig/fs/cramfs/inode.c 2006-02-10 07:22:48.000000000 +0000
+++ linux-2.6.15.4/fs/cramfs/inode.c 2006-03-02 17:38:05.000000000 +0000
@@ -36,7 +36,7 @@

/* These two macros may change in future, to provide better st_ino
semantics. */
-#define CRAMINO(x) ((x)->offset?(x)->offset<<2:1)
+#define CRAMINO(x) (((x)->offset && (x)->size)?(x)->offset<<2:1)
#define OFFSET(x) ((x)->i_ino)


@@ -66,8 +66,36 @@

static int cramfs_iget5_set(struct inode *inode, void *opaque)
{
+ static struct timespec zerotime;
struct cramfs_inode *cramfs_inode = opaque;
+ inode->i_mode = cramfs_inode->mode;
+ inode->i_uid = cramfs_inode->uid;
+ inode->i_size = cramfs_inode->size;
+ inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_gid = cramfs_inode->gid;
+ /* Struct copy intentional */
+ inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime;
inode->i_ino = CRAMINO(cramfs_inode);
+ /* inode->i_nlink is left 1 - arguably wrong for directories,
+ but it's the best we can do without reading the directory
+ contents. 1 yields the right result in GNU find, even
+ without -noleaf option. */
+ if (S_ISREG(inode->i_mode)) {
+ inode->i_fop = &generic_ro_fops;
+ inode->i_data.a_ops = &cramfs_aops;
+ } else if (S_ISDIR(inode->i_mode)) {
+ inode->i_op = &cramfs_dir_inode_operations;
+ inode->i_fop = &cramfs_directory_operations;
+ } else if (S_ISLNK(inode->i_mode)) {
+ inode->i_op = &page_symlink_inode_operations;
+ inode->i_data.a_ops = &cramfs_aops;
+ } else {
+ inode->i_size = 0;
+ inode->i_blocks = 0;
+ init_special_inode(inode, inode->i_mode,
+ old_decode_dev(cramfs_inode->size));
+ }
return 0;
}

@@ -77,37 +105,7 @@
struct inode *inode = iget5_locked(sb, CRAMINO(cramfs_inode),
cramfs_iget5_test, cramfs_iget5_set,
cramfs_inode);
- static struct timespec zerotime;
-
if (inode && (inode->i_state & I_NEW)) {
- inode->i_mode = cramfs_inode->mode;
- inode->i_uid = cramfs_inode->uid;
- inode->i_size = cramfs_inode->size;
- inode->i_blocks = (cramfs_inode->size - 1) / 512 + 1;
- inode->i_blksize = PAGE_CACHE_SIZE;
- inode->i_gid = cramfs_inode->gid;
- /* Struct copy intentional */
- inode->i_mtime = inode->i_atime = inode->i_ctime = zerotime;
- inode->i_ino = CRAMINO(cramfs_inode);
- /* inode->i_nlink is left 1 - arguably wrong for directories,
- but it's the best we can do without reading the directory
- contents. 1 yields the right result in GNU find, even
- without -noleaf option. */
- if (S_ISREG(inode->i_mode)) {
- inode->i_fop = &generic_ro_fops;
- inode->i_data.a_ops = &cramfs_aops;
- } else if (S_ISDIR(inode->i_mode)) {
- inode->i_op = &cramfs_dir_inode_operations;
- inode->i_fop = &cramfs_directory_operations;
- } else if (S_ISLNK(inode->i_mode)) {
- inode->i_op = &page_symlink_inode_operations;
- inode->i_data.a_ops = &cramfs_aops;
- } else {
- inode->i_size = 0;
- inode->i_blocks = 0;
- init_special_inode(inode, inode->i_mode,
- old_decode_dev(cramfs_inode->size));
- }
unlock_new_inode(inode);
}
return inode;