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authorAl Viro <viro@zeniv.linux.org.uk>2011-09-16 02:31:11 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-01-03 22:54:07 -0500
commitff01bb4832651c6d25ac509a06a10fcbd75c461c (patch)
treebbfdebd317db97d346df78293566f36e883b1be9 /fs/buffer.c
parent94ea4158f1733e3b10cef067d535f504866e0c41 (diff)
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fs: move code out of buffer.c
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/buffer.c')
-rw-r--r--fs/buffer.c50
1 files changed, 0 insertions, 50 deletions
diff --git a/fs/buffer.c b/fs/buffer.c
index 19d8eb7fdc81..1a30db77af32 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -41,7 +41,6 @@
#include <linux/bitops.h>
#include <linux/mpage.h>
#include <linux/bit_spinlock.h>
-#include <linux/cleancache.h>
static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
@@ -231,55 +230,6 @@ out:
return ret;
}
-/* If invalidate_buffers() will trash dirty buffers, it means some kind
- of fs corruption is going on. Trashing dirty data always imply losing
- information that was supposed to be just stored on the physical layer
- by the user.
-
- Thus invalidate_buffers in general usage is not allwowed to trash
- dirty buffers. For example ioctl(FLSBLKBUF) expects dirty data to
- be preserved. These buffers are simply skipped.
-
- We also skip buffers which are still in use. For example this can
- happen if a userspace program is reading the block device.
-
- NOTE: In the case where the user removed a removable-media-disk even if
- there's still dirty data not synced on disk (due a bug in the device driver
- or due an error of the user), by not destroying the dirty buffers we could
- generate corruption also on the next media inserted, thus a parameter is
- necessary to handle this case in the most safe way possible (trying
- to not corrupt also the new disk inserted with the data belonging to
- the old now corrupted disk). Also for the ramdisk the natural thing
- to do in order to release the ramdisk memory is to destroy dirty buffers.
-
- These are two special cases. Normal usage imply the device driver
- to issue a sync on the device (without waiting I/O completion) and
- then an invalidate_buffers call that doesn't trash dirty buffers.
-
- For handling cache coherency with the blkdev pagecache the 'update' case
- is been introduced. It is needed to re-read from disk any pinned
- buffer. NOTE: re-reading from disk is destructive so we can do it only
- when we assume nobody is changing the buffercache under our I/O and when
- we think the disk contains more recent information than the buffercache.
- The update == 1 pass marks the buffers we need to update, the update == 2
- pass does the actual I/O. */
-void invalidate_bdev(struct block_device *bdev)
-{
- struct address_space *mapping = bdev->bd_inode->i_mapping;
-
- if (mapping->nrpages == 0)
- return;
-
- invalidate_bh_lrus();
- lru_add_drain_all(); /* make sure all lru add caches are flushed */
- invalidate_mapping_pages(mapping, 0, -1);
- /* 99% of the time, we don't need to flush the cleancache on the bdev.
- * But, for the strange corners, lets be cautious
- */
- cleancache_flush_inode(mapping);
-}
-EXPORT_SYMBOL(invalidate_bdev);
-
/*
* Kick the writeback threads then try to free up some ZONE_NORMAL memory.
*/