Skip to content

Commit

Permalink
---
Browse files Browse the repository at this point in the history 
yaml
---
r: 233684
b: refs/heads/master
c: ec29ed5
h: refs/heads/master
v: v3
  • Loading branch information
Chris Mason committed Feb 23, 2011
1 parent cac28b6 commit eb59227
Show file tree
Hide file tree
Showing 4 changed files with 225 additions and 43 deletions.
2 changes: 1 addition & 1 deletion [refs]
View file
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: fb01aa85b8b29c1a4e1f4a28ea54175de6bf7559
refs/heads/master: ec29ed5b407d618a8128f5942aade9e1758aa14b
138 changes: 99 additions & 39 deletions trunk/fs/btrfs/extent_io.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) {
Expand All @@ -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)
Expand All @@ -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)
Expand Down Expand Up @@ -2912,6 +2918,46 @@ sector_t extent_bmap(struct address_space *mapping, sector_t iblock,
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)
{
Expand All @@ -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;
Expand All @@ -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) {
Expand All @@ -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;
}
last = found_key.offset;
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)) {
Expand All @@ -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;

Expand All @@ -3004,37 +3072,29 @@ 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;
}
ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
em_len, flags);
if (ret)
goto out_free;
}
out_free:
free_extent_map(em);
Expand Down
2 changes: 1 addition & 1 deletion trunk/fs/btrfs/extent_io.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down
126 changes: 124 additions & 2 deletions trunk/fs/btrfs/inode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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) {
Expand Down Expand Up @@ -5282,6 +5282,128 @@ struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
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)
{
Expand Down Expand Up @@ -6104,7 +6226,7 @@ static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
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)
Expand Down

0 comments on commit eb59227

Please sign in to comment.