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-rw-r--r--fs/block_dev.c114
1 files changed, 84 insertions, 30 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 1089dbf25925..71ccab1d22c6 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -51,6 +51,18 @@ struct block_device *I_BDEV(struct inode *inode)
}
EXPORT_SYMBOL(I_BDEV);
+void __vfs_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
+{
+ struct va_format vaf;
+ va_list args;
+
+ va_start(args, fmt);
+ vaf.fmt = fmt;
+ vaf.va = &args;
+ printk_ratelimited("%sVFS (%s): %pV\n", prefix, sb->s_id, &vaf);
+ va_end(args);
+}
+
static void bdev_write_inode(struct block_device *bdev)
{
struct inode *inode = bdev->bd_inode;
@@ -489,7 +501,7 @@ long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax)
sector += get_start_sect(bdev);
if (sector % (PAGE_SIZE / 512))
return -EINVAL;
- avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn);
+ avail = ops->direct_access(bdev, sector, &dax->addr, &dax->pfn, size);
if (!avail)
return -ERANGE;
if (avail > 0 && avail & ~PAGE_MASK)
@@ -498,6 +510,75 @@ long bdev_direct_access(struct block_device *bdev, struct blk_dax_ctl *dax)
}
EXPORT_SYMBOL_GPL(bdev_direct_access);
+/**
+ * bdev_dax_supported() - Check if the device supports dax for filesystem
+ * @sb: The superblock of the device
+ * @blocksize: The block size of the device
+ *
+ * This is a library function for filesystems to check if the block device
+ * can be mounted with dax option.
+ *
+ * Return: negative errno if unsupported, 0 if supported.
+ */
+int bdev_dax_supported(struct super_block *sb, int blocksize)
+{
+ struct blk_dax_ctl dax = {
+ .sector = 0,
+ .size = PAGE_SIZE,
+ };
+ int err;
+
+ if (blocksize != PAGE_SIZE) {
+ vfs_msg(sb, KERN_ERR, "error: unsupported blocksize for dax");
+ return -EINVAL;
+ }
+
+ err = bdev_direct_access(sb->s_bdev, &dax);
+ if (err < 0) {
+ switch (err) {
+ case -EOPNOTSUPP:
+ vfs_msg(sb, KERN_ERR,
+ "error: device does not support dax");
+ break;
+ case -EINVAL:
+ vfs_msg(sb, KERN_ERR,
+ "error: unaligned partition for dax");
+ break;
+ default:
+ vfs_msg(sb, KERN_ERR,
+ "error: dax access failed (%d)", err);
+ }
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bdev_dax_supported);
+
+/**
+ * bdev_dax_capable() - Return if the raw device is capable for dax
+ * @bdev: The device for raw block device access
+ */
+bool bdev_dax_capable(struct block_device *bdev)
+{
+ struct blk_dax_ctl dax = {
+ .size = PAGE_SIZE,
+ };
+
+ if (!IS_ENABLED(CONFIG_FS_DAX))
+ return false;
+
+ dax.sector = 0;
+ if (bdev_direct_access(bdev, &dax) < 0)
+ return false;
+
+ dax.sector = bdev->bd_part->nr_sects - (PAGE_SIZE / 512);
+ if (bdev_direct_access(bdev, &dax) < 0)
+ return false;
+
+ return true;
+}
+
/*
* pseudo-fs
*/
@@ -1160,33 +1241,6 @@ void bd_set_size(struct block_device *bdev, loff_t size)
}
EXPORT_SYMBOL(bd_set_size);
-static bool blkdev_dax_capable(struct block_device *bdev)
-{
- struct gendisk *disk = bdev->bd_disk;
-
- if (!disk->fops->direct_access || !IS_ENABLED(CONFIG_FS_DAX))
- return false;
-
- /*
- * If the partition is not aligned on a page boundary, we can't
- * do dax I/O to it.
- */
- if ((bdev->bd_part->start_sect % (PAGE_SIZE / 512))
- || (bdev->bd_part->nr_sects % (PAGE_SIZE / 512)))
- return false;
-
- /*
- * If the device has known bad blocks, force all I/O through the
- * driver / page cache.
- *
- * TODO: support finer grained dax error handling
- */
- if (disk->bb && disk->bb->count)
- return false;
-
- return true;
-}
-
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
/*
@@ -1266,7 +1320,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
if (!ret) {
bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
- if (!blkdev_dax_capable(bdev))
+ if (!bdev_dax_capable(bdev))
bdev->bd_inode->i_flags &= ~S_DAX;
}
@@ -1303,7 +1357,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
goto out_clear;
}
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
- if (!blkdev_dax_capable(bdev))
+ if (!bdev_dax_capable(bdev))
bdev->bd_inode->i_flags &= ~S_DAX;
}
} else {