Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs

* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
  logfs: handle powerfail on NAND flash
  logfs: handle errors from get_mtd_device()
  logfs: remove unused variable
  logfs: fix sync
  logfs: fix compile failure
  logfs: initialize li->li_refcount
  logfs: commit reservations under space pressure
  logfs: survive logfs_buf_recover read errors
  logfs: Close i_ino reuse race
  logfs: fix logfs_seek_hole()
  logfs: Return -EINVAL if filesystem image doesn't match
  LogFS: Fix typo in b6349ac8
  logfs: testing the wrong variable

fs/logfs/dev_bdev.c

@@ -303,6 +303,11 @@ static void bdev_put_device(struct super_block *sb)
 	close_bdev_exclusive(logfs_super(sb)->s_bdev, FMODE_READ|FMODE_WRITE);
 }
 
+static int bdev_can_write_buf(struct super_block *sb, u64 ofs)
+{
+	return 0;
+}
+
 static const struct logfs_device_ops bd_devops = {
 	.find_first_sb	= bdev_find_first_sb,
 	.find_last_sb	= bdev_find_last_sb,
@@ -310,6 +315,7 @@ static const struct logfs_device_ops bd_devops = {
 	.readpage	= bdev_readpage,
 	.writeseg	= bdev_writeseg,
 	.erase		= bdev_erase,
+	.can_write_buf	= bdev_can_write_buf,
 	.sync		= bdev_sync,
 	.put_device	= bdev_put_device,
 };

fs/logfs/dev_mtd.c

@@ -9,6 +9,7 @@
 #include <linux/completion.h>
 #include <linux/mount.h>
 #include <linux/sched.h>
+#include <linux/slab.h>
 
 #define PAGE_OFS(ofs) ((ofs) & (PAGE_SIZE-1))
 
@@ -126,7 +127,8 @@ static int mtd_readpage(void *_sb, struct page *page)
 
 	err = mtd_read(sb, page->index << PAGE_SHIFT, PAGE_SIZE,
 			page_address(page));
-	if (err == -EUCLEAN) {
+	if (err == -EUCLEAN || err == -EBADMSG) {
+		/* -EBADMSG happens regularly on power failures */
 		err = 0;
 		/* FIXME: force GC this segment */
 	}
@@ -233,12 +235,32 @@ static void mtd_put_device(struct super_block *sb)
 	put_mtd_device(logfs_super(sb)->s_mtd);
 }
 
+static int mtd_can_write_buf(struct super_block *sb, u64 ofs)
+{
+	struct logfs_super *super = logfs_super(sb);
+	void *buf;
+	int err;
+
+	buf = kmalloc(super->s_writesize, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	err = mtd_read(sb, ofs, super->s_writesize, buf);
+	if (err)
+		goto out;
+	if (memchr_inv(buf, 0xff, super->s_writesize))
+		err = -EIO;
+	kfree(buf);
+out:
+	return err;
+}
+
 static const struct logfs_device_ops mtd_devops = {
 	.find_first_sb	= mtd_find_first_sb,
 	.find_last_sb	= mtd_find_last_sb,
 	.readpage	= mtd_readpage,
 	.writeseg	= mtd_writeseg,
 	.erase		= mtd_erase,
+	.can_write_buf	= mtd_can_write_buf,
 	.sync		= mtd_sync,
 	.put_device	= mtd_put_device,
 };
@@ -250,5 +272,7 @@ int logfs_get_sb_mtd(struct file_system_type *type, int flags,
 	const struct logfs_device_ops *devops = &mtd_devops;
 
 	mtd = get_mtd_device(NULL, mtdnr);
+	if (IS_ERR(mtd))
+		return PTR_ERR(mtd);
 	return logfs_get_sb_device(type, flags, mtd, NULL, devops, mnt);
 }

fs/logfs/file.c

@@ -161,7 +161,17 @@ static int logfs_writepage(struct page *page, struct writeback_control *wbc)
 
 static void logfs_invalidatepage(struct page *page, unsigned long offset)
 {
-	move_page_to_btree(page);
+	struct logfs_block *block = logfs_block(page);
+
+	if (block->reserved_bytes) {
+		struct super_block *sb = page->mapping->host->i_sb;
+		struct logfs_super *super = logfs_super(sb);
+
+		super->s_dirty_pages -= block->reserved_bytes;
+		block->ops->free_block(sb, block);
+		BUG_ON(bitmap_weight(block->alias_map, LOGFS_BLOCK_FACTOR));
+	} else
+		move_page_to_btree(page);
 	BUG_ON(PagePrivate(page) || page->private);
 }
 
@@ -212,10 +222,8 @@ int logfs_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 int logfs_fsync(struct file *file, struct dentry *dentry, int datasync)
 {
 	struct super_block *sb = dentry->d_inode->i_sb;
-	struct logfs_super *super = logfs_super(sb);
 
-	/* FIXME: write anchor */
-	super->s_devops->sync(sb);
+	logfs_write_anchor(sb);
 	return 0;
 }
 

fs/logfs/gc.c

@@ -122,7 +122,7 @@ static void logfs_cleanse_block(struct super_block *sb, u64 ofs, u64 ino,
 	logfs_safe_iput(inode, cookie);
 }
 
-static u32 logfs_gc_segment(struct super_block *sb, u32 segno, u8 dist)
+static u32 logfs_gc_segment(struct super_block *sb, u32 segno)
 {
 	struct logfs_super *super = logfs_super(sb);
 	struct logfs_segment_header sh;
@@ -401,7 +401,7 @@ static int __logfs_gc_once(struct super_block *sb, struct gc_candidate *cand)
 			segno, (u64)segno << super->s_segshift,
 			dist, no_free_segments(sb), valid,
 			super->s_free_bytes);
-	cleaned = logfs_gc_segment(sb, segno, dist);
+	cleaned = logfs_gc_segment(sb, segno);
 	log_gc("GC segment #%02x complete - now %x valid\n", segno,
 			valid - cleaned);
 	BUG_ON(cleaned != valid);
@@ -632,38 +632,31 @@ static int check_area(struct super_block *sb, int i)
 {
 	struct logfs_super *super = logfs_super(sb);
 	struct logfs_area *area = super->s_area[i];
-	struct logfs_object_header oh;
+	gc_level_t gc_level;
+	u32 cleaned, valid, ec;
 	u32 segno = area->a_segno;
-	u32 ofs = area->a_used_bytes;
-	__be32 crc;
-	int err;
+	u64 ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
 
 	if (!area->a_is_open)
 		return 0;
 
-	for (ofs = area->a_used_bytes;
-	     ofs <= super->s_segsize - sizeof(oh);
-	     ofs += (u32)be16_to_cpu(oh.len) + sizeof(oh)) {
-		err = wbuf_read(sb, dev_ofs(sb, segno, ofs), sizeof(oh), &oh);
-		if (err)
-			return err;
-
-		if (!memchr_inv(&oh, 0xff, sizeof(oh)))
-			break;
+	if (super->s_devops->can_write_buf(sb, ofs) == 0)
+		return 0;
 
-		crc = logfs_crc32(&oh, sizeof(oh) - 4, 4);
-		if (crc != oh.crc) {
-			printk(KERN_INFO "interrupted header at %llx\n",
-					dev_ofs(sb, segno, ofs));
-			return 0;
-		}
-	}
-	if (ofs != area->a_used_bytes) {
-		printk(KERN_INFO "%x bytes unaccounted data found at %llx\n",
-				ofs - area->a_used_bytes,
-				dev_ofs(sb, segno, area->a_used_bytes));
-		area->a_used_bytes = ofs;
-	}
+	printk(KERN_INFO"LogFS: Possibly incomplete write at %llx\n", ofs);
+	/*
+	 * The device cannot write back the write buffer.  Most likely the
+	 * wbuf was already written out and the system crashed at some point
+	 * before the journal commit happened.  In that case we wouldn't have
+	 * to do anything.  But if the crash happened before the wbuf was
+	 * written out correctly, we must GC this segment.  So assume the
+	 * worst and always do the GC run.
+	 */
+	area->a_is_open = 0;
+	valid = logfs_valid_bytes(sb, segno, &ec, &gc_level);
+	cleaned = logfs_gc_segment(sb, segno);
+	if (cleaned != valid)
+		return -EIO;
 	return 0;
 }
 

fs/logfs/inode.c

@@ -193,6 +193,7 @@ static void logfs_init_inode(struct super_block *sb, struct inode *inode)
 	inode->i_ctime	= CURRENT_TIME;
 	inode->i_mtime	= CURRENT_TIME;
 	inode->i_nlink	= 1;
+	li->li_refcount = 1;
 	INIT_LIST_HEAD(&li->li_freeing_list);
 
 	for (i = 0; i < LOGFS_EMBEDDED_FIELDS; i++)
@@ -326,7 +327,7 @@ static void logfs_set_ino_generation(struct super_block *sb,
 	u64 ino;
 
 	mutex_lock(&super->s_journal_mutex);
-	ino = logfs_seek_hole(super->s_master_inode, super->s_last_ino);
+	ino = logfs_seek_hole(super->s_master_inode, super->s_last_ino + 1);
 	super->s_last_ino = ino;
 	super->s_inos_till_wrap--;
 	if (super->s_inos_till_wrap < 0) {
@@ -386,8 +387,7 @@ static void logfs_init_once(void *_li)
 
 static int logfs_sync_fs(struct super_block *sb, int wait)
 {
-	/* FIXME: write anchor */
-	logfs_super(sb)->s_devops->sync(sb);
+	logfs_write_anchor(sb);
 	return 0;
 }
 

fs/logfs/journal.c

@@ -132,10 +132,9 @@ static int read_area(struct super_block *sb, struct logfs_je_area *a)
 
 	ofs = dev_ofs(sb, area->a_segno, area->a_written_bytes);
 	if (super->s_writesize > 1)
-		logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
+		return logfs_buf_recover(area, ofs, a + 1, super->s_writesize);
 	else
-		logfs_buf_recover(area, ofs, NULL, 0);
-	return 0;
+		return logfs_buf_recover(area, ofs, NULL, 0);
 }
 
 static void *unpack(void *from, void *to)
@@ -245,7 +244,7 @@ static int read_je(struct super_block *sb, u64 ofs)
 		read_erasecount(sb, unpack(jh, scratch));
 		break;
 	case JE_AREA:
-		read_area(sb, unpack(jh, scratch));
+		err = read_area(sb, unpack(jh, scratch));
 		break;
 	case JE_OBJ_ALIAS:
 		err = logfs_load_object_aliases(sb, unpack(jh, scratch),

fs/logfs/logfs.h

@@ -144,6 +144,7 @@ struct logfs_area_ops {
  * @erase:			erase one segment
  * @read:			read from the device
  * @erase:			erase part of the device
+ * @can_write_buf:		decide whether wbuf can be written to ofs
  */
 struct logfs_device_ops {
 	struct page *(*find_first_sb)(struct super_block *sb, u64 *ofs);
@@ -153,6 +154,7 @@ struct logfs_device_ops {
 	void (*writeseg)(struct super_block *sb, u64 ofs, size_t len);
 	int (*erase)(struct super_block *sb, loff_t ofs, size_t len,
 			int ensure_write);
+	int (*can_write_buf)(struct super_block *sb, u64 ofs);
 	void (*sync)(struct super_block *sb);
 	void (*put_device)(struct super_block *sb);
 };
@@ -394,6 +396,7 @@ struct logfs_super {
 	int	 s_lock_count;
 	mempool_t *s_block_pool;		/* struct logfs_block pool */
 	mempool_t *s_shadow_pool;		/* struct logfs_shadow pool */
+	struct list_head s_writeback_list;	/* writeback pages */
 	/*
 	 * Space accounting:
 	 * - s_used_bytes specifies space used to store valid data objects.
@@ -598,19 +601,19 @@ void freeseg(struct super_block *sb, u32 segno);
 int logfs_init_areas(struct super_block *sb);
 void logfs_cleanup_areas(struct super_block *sb);
 int logfs_open_area(struct logfs_area *area, size_t bytes);
-void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
+int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 		int use_filler);
 
-static inline void logfs_buf_write(struct logfs_area *area, u64 ofs,
+static inline int logfs_buf_write(struct logfs_area *area, u64 ofs,
 		void *buf, size_t len)
 {
-	__logfs_buf_write(area, ofs, buf, len, 0);
+	return __logfs_buf_write(area, ofs, buf, len, 0);
 }
 
-static inline void logfs_buf_recover(struct logfs_area *area, u64 ofs,
+static inline int logfs_buf_recover(struct logfs_area *area, u64 ofs,
 		void *buf, size_t len)
 {
-	__logfs_buf_write(area, ofs, buf, len, 1);
+	return __logfs_buf_write(area, ofs, buf, len, 1);
 }
 
 /* super.c */

fs/logfs/readwrite.c

@@ -892,6 +892,8 @@ u64 logfs_seek_hole(struct inode *inode, u64 bix)
 		return bix;
 	else if (li->li_data[INDIRECT_INDEX] & LOGFS_FULLY_POPULATED)
 		bix = maxbix(li->li_height);
+	else if (bix >= maxbix(li->li_height))
+		return bix;
 	else {
 		bix = seek_holedata_loop(inode, bix, 0);
 		if (bix < maxbix(li->li_height))
@@ -1093,17 +1095,25 @@ static int logfs_reserve_bytes(struct inode *inode, int bytes)
 int get_page_reserve(struct inode *inode, struct page *page)
 {
 	struct logfs_super *super = logfs_super(inode->i_sb);
+	struct logfs_block *block = logfs_block(page);
 	int ret;
 
-	if (logfs_block(page) && logfs_block(page)->reserved_bytes)
+	if (block && block->reserved_bytes)
 		return 0;
 
 	logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
-	ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE);
+	while ((ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE)) &&
+			!list_empty(&super->s_writeback_list)) {
+		block = list_entry(super->s_writeback_list.next,
+				struct logfs_block, alias_list);
+		block->ops->write_block(block);
+	}
 	if (!ret) {
 		alloc_data_block(inode, page);
-		logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
+		block = logfs_block(page);
+		block->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
 		super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
+		list_move_tail(&block->alias_list, &super->s_writeback_list);
 	}
 	logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
 	return ret;
@@ -1861,7 +1871,7 @@ int logfs_truncate(struct inode *inode, u64 target)
 			size = target;
 
 		logfs_get_wblocks(sb, NULL, 1);
-		err = __logfs_truncate(inode, target);
+		err = __logfs_truncate(inode, size);
 		if (!err)
 			err = __logfs_write_inode(inode, 0);
 		logfs_put_wblocks(sb, NULL, 1);
@@ -2249,6 +2259,7 @@ int logfs_init_rw(struct super_block *sb)
 	int min_fill = 3 * super->s_no_blocks;
 
 	INIT_LIST_HEAD(&super->s_object_alias);
+	INIT_LIST_HEAD(&super->s_writeback_list);
 	mutex_init(&super->s_write_mutex);
 	super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
 			sizeof(struct logfs_block));

fs/logfs/segment.c

@@ -67,7 +67,7 @@ static struct page *get_mapping_page(struct super_block *sb, pgoff_t index,
 	return page;
 }
 
-void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
+int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 		int use_filler)
 {
 	pgoff_t index = ofs >> PAGE_SHIFT;
@@ -81,8 +81,10 @@ void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 		copylen = min((ulong)len, PAGE_SIZE - offset);
 
 		page = get_mapping_page(area->a_sb, index, use_filler);
-		SetPageUptodate(page);
+		if (IS_ERR(page))
+			return PTR_ERR(page);
 		BUG_ON(!page); /* FIXME: reserve a pool */
+		SetPageUptodate(page);
 		memcpy(page_address(page) + offset, buf, copylen);
 		SetPagePrivate(page);
 		page_cache_release(page);
@@ -92,6 +94,7 @@ void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
 		offset = 0;
 		index++;
 	} while (len);
+	return 0;
 }
 
 static void pad_partial_page(struct logfs_area *area)

fs/logfs/super.c

@@ -138,10 +138,14 @@ static int logfs_sb_set(struct super_block *sb, void *_super)
 	sb->s_fs_info = super;
 	sb->s_mtd = super->s_mtd;
 	sb->s_bdev = super->s_bdev;
+#ifdef CONFIG_BLOCK
 	if (sb->s_bdev)
 		sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info;
+#endif
+#ifdef CONFIG_MTD
 	if (sb->s_mtd)
 		sb->s_bdi = sb->s_mtd->backing_dev_info;
+#endif
 	return 0;
 }
 
@@ -382,7 +386,7 @@ static struct page *find_super_block(struct super_block *sb)
 	if (!first || IS_ERR(first))
 		return NULL;
 	last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]);
-	if (!last || IS_ERR(first)) {
+	if (!last || IS_ERR(last)) {
 		page_cache_release(first);
 		return NULL;
 	}
@@ -413,7 +417,7 @@ static int __logfs_read_sb(struct super_block *sb)
 
 	page = find_super_block(sb);
 	if (!page)
-		return -EIO;
+		return -EINVAL;
 
 	ds = page_address(page);
 	super->s_size = be64_to_cpu(ds->ds_filesystem_size);