[PATCH] cleanup for fixing get_super() races

Alexander Viro (viro@math.psu.edu)
Fri, 27 Apr 2001 20:46:56 -0400 (EDT)

A lot of drivers does the following:
sb = get_super(dev);
if (sb)
invalidate_inodes(sb);
Each of these places is an oopsable race with umount. We can't fix them
without touching a lot of drivers. However, we can make the future fix
easier if we put the above into a helper function. Patch below does that.
Results:
* simpler code in drivers
* drivers don't care about the superblocks and their handling
* when we will add refcounting for superblocks we will not need
to touch every block driver out there.
Patch is absolutely straightforward - function added to inode.c, declared
in fs.h and exported; instances of the body replaced with calls.

Please, apply it.
Al

diff -urN S4-pre8/drivers/acorn/block/mfmhd.c S4-pre8-ream_inodes/drivers/acorn/block/mfmhd.c
--- S4-pre8/drivers/acorn/block/mfmhd.c Fri Feb 16 18:37:01 2001
+++ S4-pre8-ream_inodes/drivers/acorn/block/mfmhd.c Fri Apr 27 20:16:01 2001
@@ -1486,11 +1486,9 @@
for (i = maxp - 1; i >= 0; i--) {
int minor = start + i;
kdev_t devi = MKDEV(MAJOR_NR, minor);
- struct super_block *sb = get_super(devi);

sync_dev (devi);
- if (sb)
- invalidate_inodes (sb);
+ ream_inodes(devi);
invalidate_buffers (devi);

mfm_gendisk.part[minor].start_sect = 0;
diff -urN S4-pre8/drivers/block/DAC960.c S4-pre8-ream_inodes/drivers/block/DAC960.c
--- S4-pre8/drivers/block/DAC960.c Thu Feb 22 06:46:26 2001
+++ S4-pre8-ream_inodes/drivers/block/DAC960.c Fri Apr 27 20:16:31 2001
@@ -5134,15 +5134,13 @@
PartitionNumber);
int MinorNumber = DAC960_MinorNumber(LogicalDriveNumber,
PartitionNumber);
- SuperBlock_T *SuperBlock = get_super(Device);
if (Controller->GenericDiskInfo.part[MinorNumber].nr_sects == 0)
continue;
/*
Flush all changes and invalidate buffered state.
*/
sync_dev(Device);
- if (SuperBlock != NULL)
- invalidate_inodes(SuperBlock);
+ ream_inodes(Device);
invalidate_buffers(Device);
/*
Clear existing partition sizes.
diff -urN S4-pre8/drivers/block/acsi.c S4-pre8-ream_inodes/drivers/block/acsi.c
--- S4-pre8/drivers/block/acsi.c Fri Feb 16 22:53:03 2001
+++ S4-pre8-ream_inodes/drivers/block/acsi.c Fri Apr 27 20:16:48 2001
@@ -1887,11 +1887,9 @@
for( i = max_p - 1; i >= 0 ; i-- ) {
if (gdev->part[start + i].nr_sects != 0) {
kdev_t devp = MKDEV(MAJOR_NR, start + i);
- struct super_block *sb = get_super(devp);

fsync_dev(devp);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devp);
invalidate_buffers(devp);
gdev->part[start + i].nr_sects = 0;
}
diff -urN S4-pre8/drivers/block/amiflop.c S4-pre8-ream_inodes/drivers/block/amiflop.c
--- S4-pre8/drivers/block/amiflop.c Fri Feb 16 18:59:20 2001
+++ S4-pre8-ream_inodes/drivers/block/amiflop.c Fri Apr 27 20:17:09 2001
@@ -1540,9 +1540,7 @@
break;
case FDFMTEND:
floppy_off(drive);
- sb = get_super(inode->i_rdev);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(inode->i_rdev);
invalidate_buffers(inode->i_rdev);
break;
case FDGETPRM:
diff -urN S4-pre8/drivers/block/cciss.c S4-pre8-ream_inodes/drivers/block/cciss.c
--- S4-pre8/drivers/block/cciss.c Fri Apr 27 06:20:56 2001
+++ S4-pre8-ream_inodes/drivers/block/cciss.c Fri Apr 27 20:17:30 2001
@@ -694,9 +694,8 @@
for(i=max_p; i>=0; i--) {
int minor = start+i;
kdev_t devi = MKDEV(MAJOR_NR + ctlr, minor);
- struct super_block *sb = get_super(devi);
sync_dev(devi);
- if (sb) invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);
gdev->part[minor].start_sect = 0;
gdev->part[minor].nr_sects = 0;
diff -urN S4-pre8/drivers/block/cpqarray.c S4-pre8-ream_inodes/drivers/block/cpqarray.c
--- S4-pre8/drivers/block/cpqarray.c Fri Feb 16 22:56:28 2001
+++ S4-pre8-ream_inodes/drivers/block/cpqarray.c Fri Apr 27 20:17:42 2001
@@ -1577,9 +1577,8 @@
for(i=max_p; i>=0; i--) {
int minor = start+i;
kdev_t devi = MKDEV(MAJOR_NR + ctlr, minor);
- struct super_block *sb = get_super(devi);
sync_dev(devi);
- if (sb) invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);
gdev->part[minor].start_sect = 0;
gdev->part[minor].nr_sects = 0;
diff -urN S4-pre8/drivers/block/paride/pd.c S4-pre8-ream_inodes/drivers/block/paride/pd.c
--- S4-pre8/drivers/block/paride/pd.c Fri Feb 16 22:50:44 2001
+++ S4-pre8-ream_inodes/drivers/block/paride/pd.c Fri Apr 27 20:18:36 2001
@@ -591,8 +591,6 @@
long flags;
kdev_t devp;

- struct super_block *sb;
-
unit = DEVICE_NR(dev);
if ((unit >= PD_UNITS) || (!PD.present)) return -ENODEV;

@@ -609,10 +607,7 @@
minor = p + unit*PD_PARTNS;
devp = MKDEV(MAJOR_NR, minor);
fsync_dev(devp);
-
- sb = get_super(devp);
- if (sb) invalidate_inodes(sb);
-
+ ream_inodes(devp);
invalidate_buffers(devp);
pd_hd[minor].start_sect = 0;
pd_hd[minor].nr_sects = 0;
diff -urN S4-pre8/drivers/block/ps2esdi.c S4-pre8-ream_inodes/drivers/block/ps2esdi.c
--- S4-pre8/drivers/block/ps2esdi.c Fri Apr 27 06:20:56 2001
+++ S4-pre8-ream_inodes/drivers/block/ps2esdi.c Fri Apr 27 20:17:57 2001
@@ -1146,11 +1146,9 @@
partition >= 0; partition--) {
int minor = (start | partition);
kdev_t devp = MKDEV(MAJOR_NR, minor);
- struct super_block * sb = get_super(devp);

sync_dev(devp);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devp);
invalidate_buffers(devp);
ps2esdi_gendisk.part[start + partition].start_sect = 0;
ps2esdi_gendisk.part[start + partition].nr_sects = 0;
diff -urN S4-pre8/drivers/block/xd.c S4-pre8-ream_inodes/drivers/block/xd.c
--- S4-pre8/drivers/block/xd.c Thu Feb 22 06:46:25 2001
+++ S4-pre8-ream_inodes/drivers/block/xd.c Fri Apr 27 20:18:13 2001
@@ -402,11 +402,9 @@
for (partition = xd_gendisk.max_p - 1; partition >= 0; partition--) {
int minor = (start | partition);
kdev_t devp = MKDEV(MAJOR_NR, minor);
- struct super_block * sb = get_super(devp);

sync_dev(devp);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devp);
invalidate_buffers(devp);
xd_gendisk.part[minor].start_sect = 0;
xd_gendisk.part[minor].nr_sects = 0;
diff -urN S4-pre8/drivers/i2o/i2o_block.c S4-pre8-ream_inodes/drivers/i2o/i2o_block.c
--- S4-pre8/drivers/i2o/i2o_block.c Fri Feb 16 22:53:46 2001
+++ S4-pre8-ream_inodes/drivers/i2o/i2o_block.c Fri Apr 27 20:18:51 2001
@@ -893,11 +893,9 @@
{
int m = minor+i;
kdev_t d = MKDEV(MAJOR_NR, m);
- struct super_block *sb = get_super(d);

sync_dev(d);
- if(sb)
- invalidate_inodes(sb);
+ ream_inodes(d);
invalidate_buffers(d);
i2ob_gendisk.part[m].start_sect = 0;
i2ob_gendisk.part[m].nr_sects = 0;
diff -urN S4-pre8/drivers/ide/hd.c S4-pre8-ream_inodes/drivers/ide/hd.c
--- S4-pre8/drivers/ide/hd.c Thu Feb 22 06:47:01 2001
+++ S4-pre8-ream_inodes/drivers/ide/hd.c Fri Apr 27 20:19:06 2001
@@ -893,11 +893,9 @@
for (i=max_p - 1; i >=0 ; i--) {
int minor = start + i;
kdev_t devi = MKDEV(MAJOR_NR, minor);
- struct super_block *sb = get_super(devi);

sync_dev(devi);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);
gdev->part[minor].start_sect = 0;
gdev->part[minor].nr_sects = 0;
diff -urN S4-pre8/drivers/ide/ide.c S4-pre8-ream_inodes/drivers/ide/ide.c
--- S4-pre8/drivers/ide/ide.c Fri Apr 27 06:20:57 2001
+++ S4-pre8-ream_inodes/drivers/ide/ide.c Fri Apr 27 20:19:43 2001
@@ -1762,11 +1762,9 @@
for (p = 0; p < (1<<PARTN_BITS); ++p) {
if (drive->part[p].nr_sects > 0) {
kdev_t devp = MKDEV(major, minor+p);
- struct super_block * sb = get_super(devp);
- fsync_dev (devp);
- if (sb)
- invalidate_inodes(sb);
- invalidate_buffers (devp);
+ fsync_dev(devp);
+ ream_inodes(devp);
+ invalidate_buffers(devp);
set_blocksize(devp, 1024);
}
drive->part[p].start_sect = 0;
@@ -1983,8 +1981,7 @@
for (p = 0; p < (1<<PARTN_BITS); ++p) {
if (drive->part[p].nr_sects > 0) {
kdev_t devp = MKDEV(hwif->major, minor+p);
- struct super_block * sb = get_super(devp);
- if (sb) invalidate_inodes(sb);
+ ream_inodes(devp);
invalidate_buffers (devp);
}
}
diff -urN S4-pre8/drivers/mtd/ftl.c S4-pre8-ream_inodes/drivers/mtd/ftl.c
--- S4-pre8/drivers/mtd/ftl.c Fri Feb 16 22:53:55 2001
+++ S4-pre8-ream_inodes/drivers/mtd/ftl.c Fri Apr 27 20:20:19 2001
@@ -915,9 +915,6 @@

static release_t ftl_close(struct inode *inode, struct file *file)
{
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
- struct super_block *sb = get_super(inode->i_rdev);
-#endif
int minor = MINOR(inode->i_rdev);
partition_t *part = myparts[minor >> 4];
int i;
@@ -926,9 +923,7 @@

/* Flush all writes */
fsync_dev(inode->i_rdev);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
- if (sb) invalidate_inodes(sb);
-#endif
+ ream_inodes(inode->i_rdev);
invalidate_buffers(inode->i_rdev);

/* Wait for any pending erase operations to complete */
diff -urN S4-pre8/drivers/mtd/mtdblock.c S4-pre8-ream_inodes/drivers/mtd/mtdblock.c
--- S4-pre8/drivers/mtd/mtdblock.c Fri Feb 16 22:53:55 2001
+++ S4-pre8-ream_inodes/drivers/mtd/mtdblock.c Fri Apr 27 20:20:37 2001
@@ -355,18 +355,13 @@
{
int dev;
struct mtdblk_dev *mtdblk;
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
- struct super_block * sb = get_super(inode->i_rdev);
-#endif
DEBUG(MTD_DEBUG_LEVEL1, "mtdblock_release\n");

if (inode == NULL)
release_return(-ENODEV);

fsync_dev(inode->i_rdev);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
- if (sb) invalidate_inodes(sb);
-#endif
+ ream_inodes(inode->i_rdev);
invalidate_buffers(inode->i_rdev);

dev = MINOR(inode->i_rdev);
diff -urN S4-pre8/drivers/mtd/nftl.c S4-pre8-ream_inodes/drivers/mtd/nftl.c
--- S4-pre8/drivers/mtd/nftl.c Fri Feb 16 22:53:55 2001
+++ S4-pre8-ream_inodes/drivers/mtd/nftl.c Fri Apr 27 20:20:55 2001
@@ -997,7 +997,6 @@

static int nftl_release(struct inode *inode, struct file *fp)
{
- struct super_block *sb = get_super(inode->i_rdev);
struct NFTLrecord *thisNFTL;

thisNFTL = NFTLs[MINOR(inode->i_rdev) / 16];
@@ -1005,8 +1004,7 @@
DEBUG(MTD_DEBUG_LEVEL2, "NFTL_release\n");

fsync_dev(inode->i_rdev);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(inode->i_rdev);
invalidate_buffers(inode->i_rdev);

if (thisNFTL->mtd->sync)
diff -urN S4-pre8/drivers/scsi/sd.c S4-pre8-ream_inodes/drivers/scsi/sd.c
--- S4-pre8/drivers/scsi/sd.c Fri Feb 16 22:48:36 2001
+++ S4-pre8-ream_inodes/drivers/scsi/sd.c Fri Apr 27 20:21:19 2001
@@ -1262,10 +1262,8 @@
for (i = max_p - 1; i >= 0; i--) {
int index = start + i;
kdev_t devi = MKDEV_SD_PARTITION(index);
- struct super_block *sb = get_super(devi);
sync_dev(devi);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);
sd_gendisks->part[index].start_sect = 0;
sd_gendisks->part[index].nr_sects = 0;
@@ -1315,10 +1313,8 @@
for (j = max_p - 1; j >= 0; j--) {
int index = start + j;
kdev_t devi = MKDEV_SD_PARTITION(index);
- struct super_block *sb = get_super(devi);
sync_dev(devi);
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);
sd_gendisks->part[index].start_sect = 0;
sd_gendisks->part[index].nr_sects = 0;
diff -urN S4-pre8/drivers/scsi/sr.c S4-pre8-ream_inodes/drivers/scsi/sr.c
--- S4-pre8/drivers/scsi/sr.c Thu Feb 22 06:46:36 2001
+++ S4-pre8-ream_inodes/drivers/scsi/sr.c Fri Apr 27 20:21:37 2001
@@ -870,14 +870,12 @@
for (cpnt = scsi_CDs, i = 0; i < sr_template.dev_max; i++, cpnt++)
if (cpnt->device == SDp) {
kdev_t devi = MKDEV(MAJOR_NR, i);
- struct super_block *sb = get_super(devi);

/*
* Since the cdrom is read-only, no need to sync the device.
* We should be kind to our buffer cache, however.
*/
- if (sb)
- invalidate_inodes(sb);
+ ream_inodes(devi);
invalidate_buffers(devi);

/*
diff -urN S4-pre8/fs/block_dev.c S4-pre8-ream_inodes/fs/block_dev.c
--- S4-pre8/fs/block_dev.c Fri Feb 16 22:52:03 2001
+++ S4-pre8-ream_inodes/fs/block_dev.c Fri Apr 27 20:22:09 2001
@@ -576,8 +576,7 @@
printk(KERN_DEBUG "VFS: Disk change detected on device %s\n",
bdevname(dev));

- sb = get_super(dev);
- if (sb && invalidate_inodes(sb))
+ if (ream_inodes(dev))
printk("VFS: busy inodes on changed media.\n");

destroy_buffers(dev);
diff -urN S4-pre8/fs/devfs/base.c S4-pre8-ream_inodes/fs/devfs/base.c
--- S4-pre8/fs/devfs/base.c Fri Apr 27 06:21:01 2001
+++ S4-pre8-ream_inodes/fs/devfs/base.c Fri Apr 27 20:23:23 2001
@@ -2156,7 +2156,6 @@
int tmp;
kdev_t dev = MKDEV (de->u.fcb.u.device.major, de->u.fcb.u.device.minor);
struct block_device_operations *bdops = de->u.fcb.ops;
- struct super_block * sb;
extern int warn_no_part;

if ( !S_ISBLK (de->mode) ) return 0;
@@ -2165,8 +2164,7 @@
if ( !bdops->check_media_change (dev) ) return 0;
printk ( KERN_DEBUG "VFS: Disk change detected on device %s\n",
kdevname (dev) );
- sb = get_super (dev);
- if ( sb && invalidate_inodes (sb) )
+ if (ream_inodes(dev))
printk("VFS: busy inodes on changed media..\n");
invalidate_buffers (dev);
/* Ugly hack to disable messages about unable to read partition table */
diff -urN S4-pre8/fs/inode.c S4-pre8-ream_inodes/fs/inode.c
--- S4-pre8/fs/inode.c Fri Apr 27 06:21:01 2001
+++ S4-pre8-ream_inodes/fs/inode.c Fri Apr 27 20:22:42 2001
@@ -523,6 +523,23 @@

return busy;
}
+
+/**
+ * ream_inodes - discard the inodes on a device if it's mounted
+ * @dev: device number
+ *
+ * Equivalent of invalidate_inodes, but done by device number.
+ */
+
+int ream_inodes(kdev_t dev)
+{
+ struct super_block *sb = get_super(dev);
+ int res;
+ if (sb)
+ res = invalidate_inodes(sb);
+ return res;
+}
+

/*
* This is called with the inode lock held. It searches
diff -urN S4-pre8/include/linux/fs.h S4-pre8-ream_inodes/include/linux/fs.h
--- S4-pre8/include/linux/fs.h Fri Apr 27 06:21:03 2001
+++ S4-pre8-ream_inodes/include/linux/fs.h Fri Apr 27 20:23:49 2001
@@ -1084,6 +1084,7 @@
extern void balance_dirty(kdev_t);
extern int check_disk_change(kdev_t);
extern int invalidate_inodes(struct super_block *);
+extern int ream_inodes(kdev_t);
extern void invalidate_inode_pages(struct inode *);
extern void invalidate_inode_buffers(struct inode *);
#define invalidate_buffers(dev) __invalidate_buffers((dev), 0)
diff -urN S4-pre8/kernel/ksyms.c S4-pre8-ream_inodes/kernel/ksyms.c
--- S4-pre8/kernel/ksyms.c Fri Apr 27 06:21:04 2001
+++ S4-pre8-ream_inodes/kernel/ksyms.c Fri Apr 27 20:24:06 2001
@@ -174,6 +174,7 @@
EXPORT_SYMBOL(check_disk_change);
EXPORT_SYMBOL(__invalidate_buffers);
EXPORT_SYMBOL(invalidate_inodes);
+EXPORT_SYMBOL(ream_inodes);
EXPORT_SYMBOL(invalidate_inode_pages);
EXPORT_SYMBOL(truncate_inode_pages);
EXPORT_SYMBOL(fsync_dev);

-
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