I have one IDE disk:
/dev/hda1: ext2, root
/dev/hda2: swapspace
if I run the following commands, the filesystem becomes unusable:
# swapoff /dev/hda2
# swapon /dev/hda1 #<<< NOT A TYPO, really /dev/hda1
The second call does fails, but afterwards ll_rw_block printk()'s:
"device /dev/hda1: only 4096-char blocks implemented (1024)".
I must reboot and fsck afterwards, even SysRq doesn't sync/unmount.
The reason is clear:
sys_swapon (in mm/swapfile.c) does set_blocksize(p->swap_device, PAGE_SIZE);
Maybe the cleanest patch would have set_blocksize return the original
value, so that a failed swapon can restore the original state of affairs:
That would be something like the below.
Andries
P.S. I do not understand why there are two calls set_blocksize() in
this swapfile.c. Is that an editing mistake?
-------------------------------------------------------------------
diff -u --recursive --new-file ../linux-2.2.4/linux/fs/buffer.c ./linux/fs/buffer.c
--- ../linux-2.2.4/linux/fs/buffer.c Wed Mar 24 20:08:04 1999
+++ ./linux/fs/buffer.c Fri Mar 26 21:59:04 1999
@@ -627,25 +627,28 @@
return 0;
}
-void set_blocksize(kdev_t dev, int size)
+/* return 0 if nothing changed, old blocksize otherwise */
+int set_blocksize(kdev_t dev, int size)
{
extern int *blksize_size[];
- int i, nlist;
+ int i, nlist, obs;
struct buffer_head * bh, *bhnext;
if (!blksize_size[MAJOR(dev)])
- return;
+ return 0;
/* Size must be a power of two, and between 512 and PAGE_SIZE */
if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
panic("Invalid blocksize passed to set_blocksize");
- if (blksize_size[MAJOR(dev)][MINOR(dev)] == 0 && size == BLOCK_SIZE) {
+ obs = blksize_size[MAJOR(dev)][MINOR(dev)];
+
+ if (obs == 0 && size == BLOCK_SIZE) {
blksize_size[MAJOR(dev)][MINOR(dev)] = size;
- return;
+ return 0;
}
- if (blksize_size[MAJOR(dev)][MINOR(dev)] == size)
- return;
+ if (obs == size)
+ return 0;
sync_buffers(dev, 2);
blksize_size[MAJOR(dev)][MINOR(dev)] = size;
@@ -675,6 +678,7 @@
remove_from_hash_queue(bh);
}
}
+ return obs;
}
/*
diff -u --recursive --new-file ../linux-2.2.4/linux/fs/devices.c ./linux/fs/devices.c
--- ../linux-2.2.4/linux/fs/devices.c Wed Dec 23 20:39:49 1998
+++ ./linux/fs/devices.c Fri Feb 19 23:46:56 1999
@@ -228,7 +228,7 @@
*/
int blkdev_open(struct inode * inode, struct file * filp)
{
- int ret = -ENODEV;
+ int ret = -ENXIO;
filp->f_op = get_blkfops(MAJOR(inode->i_rdev));
if (filp->f_op != NULL){
ret = 0;
diff -u --recursive --new-file ../linux-2.2.4/linux/include/linux/fs.h ./linux/include/linux/fs.h
--- ../linux-2.2.4/linux/include/linux/fs.h Wed Mar 24 20:08:09 1999
+++ ./linux/include/linux/fs.h Fri Mar 26 21:55:01 1999
@@ -842,7 +842,7 @@
if (buf)
__bforget(buf);
}
-extern void set_blocksize(kdev_t dev, int size);
+extern int set_blocksize(kdev_t dev, int size);
extern unsigned int get_hardblocksize(kdev_t dev);
extern struct buffer_head * bread(kdev_t dev, int block, int size);
extern struct buffer_head * breada(kdev_t dev,int block, int size,
diff -u --recursive --new-file ../linux-2.2.4/linux/include/linux/genhd.h ./linux/include/linux/genhd.h
--- ../linux-2.2.4/linux/include/linux/genhd.h Wed Mar 24 20:08:09 1999
+++ ./linux/include/linux/genhd.h Wed Mar 24 20:08:37 1999
@@ -39,7 +39,7 @@
#endif
#define DM6_PARTITION 0x54 /* has DDO: use xlated geom & offset */
-#define EZD_PARTITION 0x55 /* EZ-DRIVE: same as DM6 (we think) */
+#define EZD_PARTITION 0x55 /* EZ-DRIVE: remap sector 0 to 1 */
#define DM6_AUX1PARTITION 0x51 /* no DDO: use xlated geom */
#define DM6_AUX3PARTITION 0x53 /* no DDO: use xlated geom */
diff -u --recursive --new-file ../linux-2.2.4/linux/mm/swapfile.c ./linux/mm/swapfile.c
--- ../linux-2.2.4/linux/mm/swapfile.c Wed Mar 10 01:54:27 1999
+++ ./linux/mm/swapfile.c Fri Mar 26 22:05:22 1999
@@ -484,6 +484,7 @@
struct dentry * swap_dentry;
unsigned int type;
int i, j, prev;
+ int old_blocksize = 0;
int error = -EPERM;
struct file filp;
static int least_priority = 0;
@@ -531,14 +532,16 @@
if (S_ISBLK(swap_dentry->d_inode->i_mode)) {
p->swap_device = swap_dentry->d_inode->i_rdev;
- set_blocksize(p->swap_device, PAGE_SIZE);
+ old_blocksize = set_blocksize(p->swap_device, PAGE_SIZE);
filp.f_dentry = swap_dentry;
filp.f_mode = 3; /* read write */
error = blkdev_open(swap_dentry->d_inode, &filp);
if (error)
goto bad_swap_2;
- set_blocksize(p->swap_device, PAGE_SIZE);
+#if 0
+ set_blocksize(p->swap_device, PAGE_SIZE); /* again? */
+#endif
error = -ENODEV;
if (!p->swap_device ||
(blk_size[MAJOR(p->swap_device)] &&
@@ -691,6 +694,8 @@
if(filp.f_op && filp.f_op->release)
filp.f_op->release(filp.f_dentry->d_inode,&filp);
bad_swap_2:
+ if (old_blocksize)
+ set_blocksize(p->swap_device, old_blocksize);
if (p->swap_lockmap)
vfree(p->swap_lockmap);
if (p->swap_map)
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/