vserver 1.9.5.x5

[linux-2.6.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1b43058..d19d07c 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -64,8 +64,6 @@ static void kill_bdev(struct block_device *bdev)
 
 int set_blocksize(struct block_device *bdev, int size)
 {
-       int oldsize;
-
        /* Size must be a power of two, and between 512 and PAGE_SIZE */
        if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
                return -EINVAL;
@@ -74,15 +72,13 @@ int set_blocksize(struct block_device *bdev, int size)
        if (size < bdev_hardsect_size(bdev))
                return -EINVAL;
 
-       oldsize = bdev->bd_block_size;
-       if (oldsize == size)
-               return 0;
-
-       /* Ok, we're actually changing the blocksize.. */
-       sync_blockdev(bdev);
-       bdev->bd_block_size = size;
-       bdev->bd_inode->i_blkbits = blksize_bits(size);
-       kill_bdev(bdev);
+       /* Don't change the size if it is same as current */
+       if (bdev->bd_block_size != size) {
+               sync_blockdev(bdev);
+               bdev->bd_block_size = size;
+               bdev->bd_inode->i_blkbits = blksize_bits(size);
+               kill_bdev(bdev);
+       }
        return 0;
 }
 
@@ -90,12 +86,15 @@ EXPORT_SYMBOL(set_blocksize);
 
 int sb_set_blocksize(struct super_block *sb, int size)
 {
-       int bits;
-       if (set_blocksize(sb->s_bdev, size) < 0)
+       int bits = 9; /* 2^9 = 512 */
+
+       if (set_blocksize(sb->s_bdev, size))
                return 0;
+       /* If we get here, we know size is power of two
+        * and it's value is between 512 and PAGE_SIZE */
        sb->s_blocksize = size;
-       for (bits = 9, size >>= 9; size >>= 1; bits++)
-               ;
+       for (size >>= 10; size; size >>= 1)
+               ++bits;
        sb->s_blocksize_bits = bits;
        return sb->s_blocksize;
 }
@@ -138,13 +137,26 @@ static int
 blkdev_get_blocks(struct inode *inode, sector_t iblock,
                unsigned long max_blocks, struct buffer_head *bh, int create)
 {
-       if ((iblock + max_blocks) > max_block(I_BDEV(inode)))
-               return -EIO;
+       sector_t end_block = max_block(I_BDEV(inode));
+
+       if ((iblock + max_blocks) > end_block) {
+               max_blocks = end_block - iblock;
+               if ((long)max_blocks <= 0) {
+                       if (create)
+                               return -EIO;    /* write fully beyond EOF */
+                       /*
+                        * It is a read which is fully beyond EOF.  We return
+                        * a !buffer_mapped buffer
+                        */
+                       max_blocks = 0;
+               }
+       }
 
        bh->b_bdev = I_BDEV(inode);
        bh->b_blocknr = iblock;
        bh->b_size = max_blocks << inode->i_blkbits;
-       set_buffer_mapped(bh);
+       if (max_blocks)
+               set_buffer_mapped(bh);
        return 0;
 }
 
@@ -225,7 +237,7 @@ static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
  * pseudo-fs
  */
 
-static spinlock_t bdev_lock __cacheline_aligned_in_smp = SPIN_LOCK_UNLOCKED;
+static  __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
 static kmem_cache_t * bdev_cachep;
 
 static struct inode *bdev_alloc_inode(struct super_block *sb)
@@ -238,7 +250,10 @@ static struct inode *bdev_alloc_inode(struct super_block *sb)
 
 static void bdev_destroy_inode(struct inode *inode)
 {
-       kmem_cache_free(bdev_cachep, BDEV_I(inode));
+       struct bdev_inode *bdi = BDEV_I(inode);
+
+       bdi->bdev.bd_inode_backing_dev_info = NULL;
+       kmem_cache_free(bdev_cachep, bdi);
 }
 
 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
@@ -303,14 +318,9 @@ struct super_block *blockdev_superblock;
 void __init bdev_cache_init(void)
 {
        int err;
-       bdev_cachep = kmem_cache_create("bdev_cache",
-                                       sizeof(struct bdev_inode),
-                                       0,
-                                       SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT,
-                                       init_once,
-                                       NULL);
-       if (!bdev_cachep)
-               panic("Cannot create bdev_cache SLAB cache");
+       bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
+                       0, SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|SLAB_PANIC,
+                       init_once, NULL);
        err = register_filesystem(&bd_type);
        if (err)
                panic("Cannot register bdev pseudo-fs");
@@ -669,7 +679,7 @@ int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
 
 EXPORT_SYMBOL(blkdev_get);
 
-int blkdev_open(struct inode * inode, struct file * filp)
+static int blkdev_open(struct inode * inode, struct file * filp)
 {
        struct block_device *bdev;
        int res;
@@ -698,8 +708,6 @@ int blkdev_open(struct inode * inode, struct file * filp)
        return res;
 }
 
-EXPORT_SYMBOL(blkdev_open);
-
 int blkdev_put(struct block_device *bdev)
 {
        int ret = 0;
@@ -796,13 +804,14 @@ struct file_operations def_blk_fops = {
        .mmap           = generic_file_mmap,
        .fsync          = block_fsync,
        .ioctl          = block_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl   = compat_blkdev_ioctl,
+#endif
        .readv          = generic_file_readv,
        .writev         = generic_file_write_nolock,
        .sendfile       = generic_file_sendfile,
 };
 
-EXPORT_SYMBOL(def_blk_fops);
-
 int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg)
 {
        int res;