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Message-ID: <20070624014654.GC17609@wotan.suse.de>
Date: Sun, 24 Jun 2007 03:46:54 +0200
From: Nick Piggin <npiggin@...e.de>
To: Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
Linux Memory Management List <linux-mm@...ck.org>,
linux-fsdevel@...r.kernel.org
Subject: [patch 2/3] block_dev: convert to fsblock
Convert block_dev mostly to fsblocks.
---
fs/block_dev.c | 204 +++++++++++++++++++++++++++++++++++++++-----
fs/buffer.c | 113 ++----------------------
fs/super.c | 2
include/linux/buffer_head.h | 9 -
include/linux/fs.h | 29 ++++++
5 files changed, 225 insertions(+), 132 deletions(-)
Index: linux-2.6/fs/block_dev.c
===================================================================
--- linux-2.6.orig/fs/block_dev.c
+++ linux-2.6/fs/block_dev.c
@@ -16,7 +16,9 @@
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/blkpg.h>
+#include <linux/fsblock.h>
#include <linux/buffer_head.h>
+#include <linux/pagevec.h>
#include <linux/writeback.h>
#include <linux/mpage.h>
#include <linux/mount.h>
@@ -61,14 +63,14 @@ static void kill_bdev(struct block_devic
{
if (bdev->bd_inode->i_mapping->nrpages == 0)
return;
- invalidate_bh_lrus();
+ invalidate_bh_lrus(); /* XXX: this can go when buffers goes */
truncate_inode_pages(bdev->bd_inode->i_mapping, 0);
}
int set_blocksize(struct block_device *bdev, int size)
{
/* Size must be a power of two, and between 512 and PAGE_SIZE */
- if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
+ if (size < 512 || !is_power_of_2(size))
return -EINVAL;
/* Size cannot be smaller than the size supported by the device */
@@ -92,7 +94,7 @@ int sb_set_blocksize(struct super_block
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 */
+ * and it's value is >= 512 */
sb->s_blocksize = size;
sb->s_blocksize_bits = blksize_bits(size);
return sb->s_blocksize;
@@ -112,19 +114,12 @@ EXPORT_SYMBOL(sb_min_blocksize);
static int
blkdev_get_block(struct inode *inode, sector_t iblock,
- struct buffer_head *bh, int create)
+ struct buffer_head *bh, int create)
{
if (iblock >= max_block(I_BDEV(inode))) {
if (create)
return -EIO;
-
- /*
- * for reads, we're just trying to fill a partial page.
- * return a hole, they will have to call get_block again
- * before they can fill it, and they will get -EIO at that
- * time
- */
- return 0;
+ return 0;
}
bh->b_bdev = I_BDEV(inode);
bh->b_blocknr = iblock;
@@ -132,6 +127,66 @@ blkdev_get_block(struct inode *inode, se
return 0;
}
+static int blkdev_insert_mapping(struct address_space *mapping, loff_t off,
+ size_t len, int create)
+{
+ sector_t blocknr;
+ struct inode *inode = mapping->host;
+ pgoff_t next, end;
+ struct pagevec pvec;
+ int ret = 0;
+
+ pagevec_init(&pvec, 0);
+ next = off >> PAGE_CACHE_SHIFT;
+ end = (off + len) >> PAGE_CACHE_SHIFT;
+ blocknr = off >> inode->i_blkbits;
+ while (next <= end && pagevec_lookup(&pvec, mapping, next,
+ min(end - next, (pgoff_t)PAGEVEC_SIZE))) {
+ unsigned int i;
+
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct fsblock *block;
+ struct page *page = pvec.pages[i];
+
+ BUG_ON(page->index != next);
+ BUG_ON(blocknr != pgoff_sector(next, inode->i_blkbits));
+ BUG_ON(!PageLocked(page));
+
+ if (blocknr >= max_block(I_BDEV(inode))) {
+ if (create)
+ ret = -ENOMEM;
+
+ /*
+ * for reads, we're just trying to fill a
+ * partial page. return a hole, they will
+ * have to call in again before they can fill
+ * it, and they will get -EIO at that time
+ */
+ continue; /* xxx: could be smarter, stop now */
+ }
+
+ block = page_blocks(page);
+ if (fsblock_subpage(block)) {
+ struct fsblock *b;
+ for_each_block(block, b) {
+ if (!test_bit(BL_mapped, &b->flags))
+ map_fsblock(b, blocknr);
+ blocknr++;
+ }
+ } else {
+ if (!test_bit(BL_mapped, &block->flags))
+ map_fsblock(block, blocknr);
+ blocknr++;
+ }
+ next++;
+ }
+ pagevec_release(&pvec);
+ }
+
+ return ret;
+}
+
+#if 0
static int
blkdev_get_blocks(struct inode *inode, sector_t iblock,
struct buffer_head *bh, int create)
@@ -170,6 +225,7 @@ blkdev_direct_IO(int rw, struct kiocb *i
return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
iov, offset, nr_segs, blkdev_get_blocks, NULL);
}
+#endif
#if 0
static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error)
@@ -368,24 +424,127 @@ backout:
}
#endif
+/*
+ * Write out and wait upon all the dirty data associated with a block
+ * device via its mapping. Does not take the superblock lock.
+ */
+int sync_blockdev(struct block_device *bdev)
+{
+ int ret = 0;
+
+ if (bdev)
+ ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
+ return ret;
+}
+EXPORT_SYMBOL(sync_blockdev);
+
+/*
+ * Write out and wait upon all dirty data associated with this
+ * device. Filesystem data as well as the underlying block
+ * device. Takes the superblock lock.
+ */
+int fsync_bdev(struct block_device *bdev)
+{
+ struct super_block *sb = get_super(bdev);
+ if (sb) {
+ int res = fsync_super(sb);
+ drop_super(sb);
+ return res;
+ }
+ return sync_blockdev(bdev);
+}
+
+/**
+ * freeze_bdev -- lock a filesystem and force it into a consistent state
+ * @bdev: blockdevice to lock
+ *
+ * This takes the block device bd_mount_mutex to make sure no new mounts
+ * happen on bdev until thaw_bdev() is called.
+ * If a superblock is found on this device, we take the s_umount semaphore
+ * on it to make sure nobody unmounts until the snapshot creation is done.
+ */
+struct super_block *freeze_bdev(struct block_device *bdev)
+{
+ struct super_block *sb;
+
+ down(&bdev->bd_mount_sem);
+ sb = get_super(bdev);
+ if (sb && !(sb->s_flags & MS_RDONLY)) {
+ sb->s_frozen = SB_FREEZE_WRITE;
+ smp_wmb();
+
+ __fsync_super(sb);
+
+ sb->s_frozen = SB_FREEZE_TRANS;
+ smp_wmb();
+
+ sync_blockdev(sb->s_bdev);
+
+ if (sb->s_op->write_super_lockfs)
+ sb->s_op->write_super_lockfs(sb);
+ }
+
+ sync_blockdev(bdev);
+ return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */
+}
+EXPORT_SYMBOL(freeze_bdev);
+
+/**
+ * thaw_bdev -- unlock filesystem
+ * @bdev: blockdevice to unlock
+ * @sb: associated superblock
+ *
+ * Unlocks the filesystem and marks it writeable again after freeze_bdev().
+ */
+void thaw_bdev(struct block_device *bdev, struct super_block *sb)
+{
+ if (sb) {
+ BUG_ON(sb->s_bdev != bdev);
+
+ if (sb->s_op->unlockfs)
+ sb->s_op->unlockfs(sb);
+ sb->s_frozen = SB_UNFROZEN;
+ smp_wmb();
+ wake_up(&sb->s_wait_unfrozen);
+ drop_super(sb);
+ }
+
+ up(&bdev->bd_mount_sem);
+}
+EXPORT_SYMBOL(thaw_bdev);
+
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
{
- return block_write_full_page(page, blkdev_get_block, wbc);
+ if (PagePrivate(page))
+ return block_write_full_page(page, blkdev_get_block, wbc);
+ return fsblock_write_page(page, blkdev_insert_mapping, wbc);
}
static int blkdev_readpage(struct file * file, struct page * page)
{
- return block_read_full_page(page, blkdev_get_block);
+ return fsblock_read_page(page, blkdev_insert_mapping);
}
static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
{
- return block_prepare_write(page, from, to, blkdev_get_block);
+ if (PagePrivate(page))
+ return block_prepare_write(page, from, to, blkdev_get_block);
+ return fsblock_prepare_write(page, from, to, blkdev_insert_mapping);
}
static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to)
{
- return block_commit_write(page, from, to);
+ if (PagePrivate(page))
+ return generic_commit_write(file, page, from, to);
+ return fsblock_commit_write(file, page, from, to);
+}
+
+static void blkdev_invalidate_page(struct page *page, unsigned long offset)
+{
+ if (PagePrivate(page))
+ block_invalidatepage(page, offset);
+ else
+ fsblock_invalidate_page(page, offset);
}
/*
@@ -840,7 +999,7 @@ static void free_bd_holder(struct bd_hol
/**
* find_bd_holder - find matching struct bd_holder from the block device
*
- * @bdev: struct block device to be searched
+ * @bdev: struct fsblock device to be searched
* @bo: target struct bd_holder
*
* Returns matching entry with @bo in @bdev->bd_holder_list.
@@ -1272,6 +1431,10 @@ static int __blkdev_put(struct block_dev
bdev->bd_part_count--;
if (!--bdev->bd_openers) {
+ /*
+ * XXX: This could go away when block dev and inode
+ * mappings are in sync?
+ */
sync_blockdev(bdev);
kill_bdev(bdev);
}
@@ -1325,11 +1488,14 @@ static long block_ioctl(struct file *fil
const struct address_space_operations def_blk_aops = {
.readpage = blkdev_readpage,
.writepage = blkdev_writepage,
- .sync_page = block_sync_page,
+// .sync_page = block_sync_page, /* xxx: gone w/ explicit plugging */
.prepare_write = blkdev_prepare_write,
.commit_write = blkdev_commit_write,
.writepages = generic_writepages,
- .direct_IO = blkdev_direct_IO,
+// .direct_IO = blkdev_direct_IO,
+ .set_page_dirty = fsblock_set_page_dirty,
+ .invalidatepage = blkdev_invalidate_page,
+ /* XXX: .sync */
};
const struct file_operations def_blk_fops = {
Index: linux-2.6/fs/buffer.c
===================================================================
--- linux-2.6.orig/fs/buffer.c
+++ linux-2.6/fs/buffer.c
@@ -147,95 +147,6 @@ void end_buffer_write_sync(struct buffer
}
/*
- * Write out and wait upon all the dirty data associated with a block
- * device via its mapping. Does not take the superblock lock.
- */
-int sync_blockdev(struct block_device *bdev)
-{
- int ret = 0;
-
- if (bdev)
- ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
- return ret;
-}
-EXPORT_SYMBOL(sync_blockdev);
-
-/*
- * Write out and wait upon all dirty data associated with this
- * device. Filesystem data as well as the underlying block
- * device. Takes the superblock lock.
- */
-int fsync_bdev(struct block_device *bdev)
-{
- struct super_block *sb = get_super(bdev);
- if (sb) {
- int res = fsync_super(sb);
- drop_super(sb);
- return res;
- }
- return sync_blockdev(bdev);
-}
-
-/**
- * freeze_bdev -- lock a filesystem and force it into a consistent state
- * @bdev: blockdevice to lock
- *
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
- * If a superblock is found on this device, we take the s_umount semaphore
- * on it to make sure nobody unmounts until the snapshot creation is done.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
- struct super_block *sb;
-
- down(&bdev->bd_mount_sem);
- sb = get_super(bdev);
- if (sb && !(sb->s_flags & MS_RDONLY)) {
- sb->s_frozen = SB_FREEZE_WRITE;
- smp_wmb();
-
- __fsync_super(sb);
-
- sb->s_frozen = SB_FREEZE_TRANS;
- smp_wmb();
-
- sync_blockdev(sb->s_bdev);
-
- if (sb->s_op->write_super_lockfs)
- sb->s_op->write_super_lockfs(sb);
- }
-
- sync_blockdev(bdev);
- return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev -- unlock filesystem
- * @bdev: blockdevice to unlock
- * @sb: associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-void thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
- if (sb) {
- BUG_ON(sb->s_bdev != bdev);
-
- if (sb->s_op->unlockfs)
- sb->s_op->unlockfs(sb);
- sb->s_frozen = SB_UNFROZEN;
- smp_wmb();
- wake_up(&sb->s_wait_unfrozen);
- drop_super(sb);
- }
-
- up(&bdev->bd_mount_sem);
-}
-EXPORT_SYMBOL(thaw_bdev);
-
-/*
* Various filesystems appear to want __find_get_block to be non-blocking.
* But it's the page lock which protects the buffers. To get around this,
* we get exclusion from try_to_free_buffers with the blockdev mapping's
@@ -574,11 +485,6 @@ static inline void __remove_assoc_queue(
bh->b_assoc_map = NULL;
}
-int inode_has_buffers(struct inode *inode)
-{
- return !list_empty(&inode->i_data.private_list);
-}
-
/*
* osync is designed to support O_SYNC io. It waits synchronously for
* all already-submitted IO to complete, but does not queue any new
@@ -818,8 +724,9 @@ static int fsync_buffers_list(spinlock_t
*/
void invalidate_inode_buffers(struct inode *inode)
{
- if (inode_has_buffers(inode)) {
- struct address_space *mapping = &inode->i_data;
+ struct address_space *mapping = &inode->i_data;
+
+ if (mapping_has_private(mapping)) {
struct list_head *list = &mapping->private_list;
struct address_space *buffer_mapping = mapping->assoc_mapping;
@@ -838,10 +745,10 @@ void invalidate_inode_buffers(struct ino
*/
int remove_inode_buffers(struct inode *inode)
{
+ struct address_space *mapping = &inode->i_data;
int ret = 1;
- if (inode_has_buffers(inode)) {
- struct address_space *mapping = &inode->i_data;
+ if (mapping_has_private(mapping)) {
struct list_head *list = &mapping->private_list;
struct address_space *buffer_mapping = mapping->assoc_mapping;
@@ -990,7 +897,7 @@ grow_dev_page(struct block_device *bdev,
BUG_ON(!PageLocked(page));
if (PageBlocks(page)) {
- if (try_to_free_blocks(page))
+ if (!try_to_free_blocks(page))
return NULL;
}
@@ -1603,7 +1510,7 @@ static int __block_write_full_page(struc
if (!page_has_buffers(page)) {
if (PageBlocks(page)) {
- if (try_to_free_blocks(page))
+ if (!try_to_free_blocks(page))
return -EBUSY;
}
create_empty_buffers(page, blocksize,
@@ -1769,7 +1676,7 @@ static int __block_prepare_write(struct
blocksize = 1 << inode->i_blkbits;
if (!page_has_buffers(page)) {
if (PageBlocks(page)) {
- if (try_to_free_blocks(page))
+ if (!try_to_free_blocks(page))
return -EBUSY;
}
create_empty_buffers(page, blocksize, 0);
@@ -1928,7 +1835,7 @@ int block_read_full_page(struct page *pa
blocksize = 1 << inode->i_blkbits;
if (!page_has_buffers(page)) {
if (PageBlocks(page)) {
- if (try_to_free_blocks(page))
+ if (!try_to_free_blocks(page))
return -EBUSY;
}
create_empty_buffers(page, blocksize, 0);
@@ -2497,7 +2404,7 @@ int block_truncate_page(struct address_s
if (!page_has_buffers(page)) {
if (PageBlocks(page)) {
- if (try_to_free_blocks(page))
+ if (!try_to_free_blocks(page))
return -EBUSY;
}
create_empty_buffers(page, blocksize, 0);
Index: linux-2.6/fs/super.c
===================================================================
--- linux-2.6.orig/fs/super.c
+++ linux-2.6/fs/super.c
@@ -28,7 +28,7 @@
#include <linux/blkdev.h>
#include <linux/quotaops.h>
#include <linux/namei.h>
-#include <linux/buffer_head.h> /* for fsync_super() */
+#include <linux/fs.h> /* for fsync_super() */
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/syscalls.h>
Index: linux-2.6/include/linux/buffer_head.h
===================================================================
--- linux-2.6.orig/include/linux/buffer_head.h
+++ linux-2.6/include/linux/buffer_head.h
@@ -158,22 +158,14 @@ void end_buffer_write_sync(struct buffer
/* Things to do with buffers at mapping->private_list */
void mark_buffer_dirty_inode(struct buffer_head *bh, struct inode *inode);
-int inode_has_buffers(struct inode *);
void invalidate_inode_buffers(struct inode *);
int remove_inode_buffers(struct inode *inode);
int sync_mapping_buffers(struct address_space *mapping);
void unmap_underlying_metadata(struct block_device *bdev, sector_t block);
void mark_buffer_async_write(struct buffer_head *bh);
-void invalidate_bdev(struct block_device *);
-int sync_blockdev(struct block_device *bdev);
void __wait_on_buffer(struct buffer_head *);
wait_queue_head_t *bh_waitq_head(struct buffer_head *bh);
-int fsync_bdev(struct block_device *);
-struct super_block *freeze_bdev(struct block_device *);
-void thaw_bdev(struct block_device *, struct super_block *);
-int fsync_super(struct super_block *);
-int fsync_no_super(struct block_device *);
struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
unsigned size);
struct buffer_head *__getblk(struct block_device *bdev, sector_t block,
@@ -317,7 +309,6 @@ extern int __set_page_dirty_buffers(stru
static inline void buffer_init(void) {}
static inline int try_to_free_buffers(struct page *page) { return 1; }
static inline int sync_blockdev(struct block_device *bdev) { return 0; }
-static inline int inode_has_buffers(struct inode *inode) { return 0; }
static inline void invalidate_inode_buffers(struct inode *inode) {}
static inline int remove_inode_buffers(struct inode *inode) { return 1; }
static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h
+++ linux-2.6/include/linux/fs.h
@@ -430,6 +430,20 @@ struct address_space_operations {
int (*migratepage) (struct address_space *,
struct page *, struct page *);
int (*launder_page) (struct page *);
+
+ /*
+ * release_mapping releases any private data on the mapping so that
+ * it may be reclaimed. Returns 1 on success or 0 on failure. Second
+ * parameter 'force' causes dirty data to be invalidated. (XXX: could
+ * have other flags like sync/async, etc).
+ */
+ int (*release)(struct address_space *, int);
+
+ /*
+ * sync writes back and waits for any private data on the mapping,
+ * as a data consistency operation.
+ */
+ int (*sync)(struct address_space *);
};
struct backing_dev_info;
@@ -497,6 +511,14 @@ struct block_device {
int mapping_tagged(struct address_space *mapping, int tag);
/*
+ * Does this mapping have anything on its private list?
+ */
+static inline int mapping_has_private(struct address_space *mapping)
+{
+ return !list_empty(&mapping->private_list);
+}
+
+/*
* Might pages of this file be mapped into userspace?
*/
static inline int mapping_mapped(struct address_space *mapping)
@@ -1503,6 +1525,13 @@ extern void bd_forget(struct inode *inod
extern void bdput(struct block_device *);
extern struct block_device *open_by_devnum(dev_t, unsigned);
extern const struct address_space_operations def_blk_aops;
+void invalidate_bdev(struct block_device *);
+int sync_blockdev(struct block_device *bdev);
+struct super_block *freeze_bdev(struct block_device *);
+void thaw_bdev(struct block_device *, struct super_block *);
+int fsync_bdev(struct block_device *);
+int fsync_super(struct super_block *);
+int fsync_no_super(struct block_device *);
#else
static inline void bd_forget(struct inode *inode) {}
#endif
-
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