Btrfs: fix fiemap bugs with delalloc (ec29ed5b) · Commits · 戴 / test

fs/btrfs/extent_io.c

+99 −39

Original line number	Diff line number	Diff line
		@@ -1433,12 +1433,13 @@ int extent_clear_unlock_delalloc(struct inode *inode,
		*/
		u64 count_range_bits(struct extent_io_tree *tree,
		u64 *start, u64 search_end, u64 max_bytes,
		unsigned long bits)
		unsigned long bits, int contig)
		{
		struct rb_node *node;
		struct extent_state *state;
		u64 cur_start = *start;
		u64 total_bytes = 0;
		u64 last = 0;
		int found = 0;

		if (search_end <= cur_start) {
		@@ -1463,7 +1464,9 @@ u64 count_range_bits(struct extent_io_tree *tree,
		state = rb_entry(node, struct extent_state, rb_node);
		if (state->start > search_end)
		break;
		if (state->end >= cur_start && (state->state & bits)) {
		if (contig && found && state->start > last + 1)
		break;
		if (state->end >= cur_start && (state->state & bits) == bits) {
		total_bytes += min(search_end, state->end) + 1 -
		max(cur_start, state->start);
		if (total_bytes >= max_bytes)
		@@ -1472,6 +1475,9 @@ u64 count_range_bits(struct extent_io_tree *tree,
		*start = state->start;
		found = 1;
		}
		last = state->end;
		} else if (contig && found) {
		break;
		}
		node = rb_next(node);
		if (!node)
		@@ -2912,6 +2918,46 @@ out:
		return sector;
		}

		/*
		* helper function for fiemap, which doesn't want to see any holes.
		* This maps until we find something past 'last'
		*/
		static struct extent_map get_extent_skip_holes(struct inode inode,
		u64 offset,
		u64 last,
		get_extent_t *get_extent)
		{
		u64 sectorsize = BTRFS_I(inode)->root->sectorsize;
		struct extent_map *em;
		u64 len;

		if (offset >= last)
		return NULL;

		while(1) {
		len = last - offset;
		if (len == 0)
		break;
		len = (len + sectorsize - 1) & ~(sectorsize - 1);
		em = get_extent(inode, NULL, 0, offset, len, 0);
		if (!em \|\| IS_ERR(em))
		return em;

		/* if this isn't a hole return it */
		if (!test_bit(EXTENT_FLAG_VACANCY, &em->flags) &&
		em->block_start != EXTENT_MAP_HOLE) {
		return em;
		}

		/* this is a hole, advance to the next extent */
		offset = extent_map_end(em);
		free_extent_map(em);
		if (offset >= last)
		break;
		}
		return NULL;
		}

		int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		__u64 start, __u64 len, get_extent_t *get_extent)
		{
		@@ -2921,16 +2967,19 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		u32 flags = 0;
		u32 found_type;
		u64 last;
		u64 last_for_get_extent = 0;
		u64 disko = 0;
		u64 isize = i_size_read(inode);
		struct btrfs_key found_key;
		struct extent_map *em = NULL;
		struct extent_state *cached_state = NULL;
		struct btrfs_path *path;
		struct btrfs_file_extent_item *item;
		int end = 0;
		u64 em_start = 0, em_len = 0;
		u64 em_start = 0;
		u64 em_len = 0;
		u64 em_end = 0;
		unsigned long emflags;
		int hole = 0;

		if (len == 0)
		return -EINVAL;
		@@ -2940,6 +2989,10 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		return -ENOMEM;
		path->leave_spinning = 1;

		/*
		* lookup the last file extent. We're not using i_size here
		* because there might be preallocation past i_size
		*/
		ret = btrfs_lookup_file_extent(NULL, BTRFS_I(inode)->root,
		path, inode->i_ino, -1, 0);
		if (ret < 0) {
		@@ -2953,18 +3006,38 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
		found_type = btrfs_key_type(&found_key);

		/* No extents, just return */
		/* No extents, but there might be delalloc bits */
		if (found_key.objectid != inode->i_ino \|\|
		found_type != BTRFS_EXTENT_DATA_KEY) {
		btrfs_free_path(path);
		return 0;
		}
		/* have to trust i_size as the end */
		last = (u64)-1;
		last_for_get_extent = isize;
		} else {
		/*
		* remember the start of the last extent. There are a
		* bunch of different factors that go into the length of the
		* extent, so its much less complex to remember where it started
		*/
		last = found_key.offset;
		last_for_get_extent = last + 1;
		}
		btrfs_free_path(path);

		/*
		* we might have some extents allocated but more delalloc past those
		* extents. so, we trust isize unless the start of the last extent is
		* beyond isize
		*/
		if (last < isize) {
		last = (u64)-1;
		last_for_get_extent = isize;
		}

		lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
		&cached_state, GFP_NOFS);
		em = get_extent(inode, NULL, 0, off, max - off, 0);

		em = get_extent_skip_holes(inode, off, last_for_get_extent,
		get_extent);
		if (!em)
		goto out;
		if (IS_ERR(em)) {
		@@ -2973,19 +3046,14 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		}

		while (!end) {
		hole = 0;
		off = em->start + em->len;
		off = extent_map_end(em);
		if (off >= max)
		end = 1;

		if (em->block_start == EXTENT_MAP_HOLE) {
		hole = 1;
		goto next;
		}

		em_start = em->start;
		em_len = em->len;

		em_end = extent_map_end(em);
		emflags = em->flags;
		disko = 0;
		flags = 0;

		@@ -3004,38 +3072,30 @@ int extent_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags))
		flags \|= FIEMAP_EXTENT_ENCODED;

		next:
		emflags = em->flags;
		free_extent_map(em);
		em = NULL;
		if (!end) {
		em = get_extent(inode, NULL, 0, off, max - off, 0);
		if (!em)
		goto out;
		if (IS_ERR(em)) {
		ret = PTR_ERR(em);
		goto out;
		}
		emflags = em->flags;
		}

		if (test_bit(EXTENT_FLAG_VACANCY, &emflags)) {
		if ((em_start >= last) \|\| em_len == (u64)-1 \|\|
		(last == (u64)-1 && isize <= em_end)) {
		flags \|= FIEMAP_EXTENT_LAST;
		end = 1;
		}

		if (em_start == last) {
		/* now scan forward to see if this is really the last extent. */
		em = get_extent_skip_holes(inode, off, last_for_get_extent,
		get_extent);
		if (IS_ERR(em)) {
		ret = PTR_ERR(em);
		goto out;
		}
		if (!em) {
		flags \|= FIEMAP_EXTENT_LAST;
		end = 1;
		}

		if (!hole) {
		ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
		em_len, flags);
		if (ret)
		goto out_free;
		}
		}
		out_free:
		free_extent_map(em);
		out:

fs/btrfs/extent_io.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -191,7 +191,7 @@ void extent_io_exit(void);

		u64 count_range_bits(struct extent_io_tree *tree,
		u64 *start, u64 search_end,
		u64 max_bytes, unsigned long bits);
		u64 max_bytes, unsigned long bits, int contig);

		void free_extent_state(struct extent_state *state);
		int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end,

fs/btrfs/inode.c

+124 −2

Original line number	Diff line number	Diff line
		@@ -1913,7 +1913,7 @@ static int btrfs_clean_io_failures(struct inode *inode, u64 start)

		private = 0;
		if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
		(u64)-1, 1, EXTENT_DIRTY)) {
		(u64)-1, 1, EXTENT_DIRTY, 0)) {
		ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
		start, &private_failure);
		if (ret == 0) {
		@@ -5282,6 +5282,128 @@ out:
		return em;
		}

		struct extent_map btrfs_get_extent_fiemap(struct inode inode, struct page *page,
		size_t pg_offset, u64 start, u64 len,
		int create)
		{
		struct extent_map *em;
		struct extent_map *hole_em = NULL;
		u64 range_start = start;
		u64 end;
		u64 found;
		u64 found_end;
		int err = 0;

		em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
		if (IS_ERR(em))
		return em;
		if (em) {
		/*
		* if our em maps to a hole, there might
		* actually be delalloc bytes behind it
		*/
		if (em->block_start != EXTENT_MAP_HOLE)
		return em;
		else
		hole_em = em;
		}

		/* check to see if we've wrapped (len == -1 or similar) */
		end = start + len;
		if (end < start)
		end = (u64)-1;
		else
		end -= 1;

		em = NULL;

		/* ok, we didn't find anything, lets look for delalloc */
		found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
		end, len, EXTENT_DELALLOC, 1);
		found_end = range_start + found;
		if (found_end < range_start)
		found_end = (u64)-1;

		/*
		* we didn't find anything useful, return
		* the original results from get_extent()
		*/
		if (range_start > end \|\| found_end <= start) {
		em = hole_em;
		hole_em = NULL;
		goto out;
		}

		/* adjust the range_start to make sure it doesn't
		* go backwards from the start they passed in
		*/
		range_start = max(start,range_start);
		found = found_end - range_start;

		if (found > 0) {
		u64 hole_start = start;
		u64 hole_len = len;

		em = alloc_extent_map(GFP_NOFS);
		if (!em) {
		err = -ENOMEM;
		goto out;
		}
		/*
		* when btrfs_get_extent can't find anything it
		* returns one huge hole
		*
		* make sure what it found really fits our range, and
		* adjust to make sure it is based on the start from
		* the caller
		*/
		if (hole_em) {
		u64 calc_end = extent_map_end(hole_em);

		if (calc_end <= start \|\| (hole_em->start > end)) {
		free_extent_map(hole_em);
		hole_em = NULL;
		} else {
		hole_start = max(hole_em->start, start);
		hole_len = calc_end - hole_start;
		}
		}
		em->bdev = NULL;
		if (hole_em && range_start > hole_start) {
		/* our hole starts before our delalloc, so we
		* have to return just the parts of the hole
		* that go until the delalloc starts
		*/
		em->len = min(hole_len,
		range_start - hole_start);
		em->start = hole_start;
		em->orig_start = hole_start;
		/*
		* don't adjust block start at all,
		* it is fixed at EXTENT_MAP_HOLE
		*/
		em->block_start = hole_em->block_start;
		em->block_len = hole_len;
		} else {
		em->start = range_start;
		em->len = found;
		em->orig_start = range_start;
		em->block_start = EXTENT_MAP_DELALLOC;
		em->block_len = found;
		}
		} else if (hole_em) {
		return hole_em;
		}
		out:

		free_extent_map(hole_em);
		if (err) {
		free_extent_map(em);
		return ERR_PTR(err);
		}
		return em;
		}

		static struct extent_map btrfs_new_extent_direct(struct inode inode,
		u64 start, u64 len)
		{
		@@ -6104,7 +6226,7 @@ out:
		static int btrfs_fiemap(struct inode inode, struct fiemap_extent_info fieinfo,
		__u64 start, __u64 len)
		{
		return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent);
		return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
		}

		int btrfs_readpage(struct file file, struct page page)

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