Btrfs: Add fallocate support v2
This patch updates btrfs-progs for fallocate support.
fallocate is a little different in Btrfs because we need to tell the
COW system that a given preallocated extent doesn't need to be
cow'd as long as there are no snapshots of it. This leverages the
-o nodatacow checks.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3e6f056..789c376 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -37,6 +37,7 @@
#include <linux/version.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
+#include <linux/falloc.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
@@ -587,7 +588,7 @@
* blocks on disk
*/
static int run_delalloc_nocow(struct inode *inode, struct page *locked_page,
- u64 start, u64 end, int *page_started)
+ u64 start, u64 end, int *page_started, int force)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
@@ -602,6 +603,7 @@
u64 num_bytes;
int extent_type;
int ret;
+ int type;
int nocow;
int check_prev = 1;
@@ -654,7 +656,8 @@
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
- if (extent_type == BTRFS_FILE_EXTENT_REG) {
+ if (extent_type == BTRFS_FILE_EXTENT_REG ||
+ extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
struct btrfs_block_group_cache *block_group;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_end = found_key.offset +
@@ -669,6 +672,8 @@
goto out_check;
if (disk_bytenr == 0)
goto out_check;
+ if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
+ goto out_check;
if (btrfs_cross_ref_exist(trans, root, disk_bytenr))
goto out_check;
block_group = btrfs_lookup_block_group(root->fs_info,
@@ -709,10 +714,39 @@
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
+ if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
+ struct extent_map *em;
+ struct extent_map_tree *em_tree;
+ em_tree = &BTRFS_I(inode)->extent_tree;
+ em = alloc_extent_map(GFP_NOFS);
+ em->start = cur_offset;
+ em->len = num_bytes;
+ em->block_len = num_bytes;
+ em->block_start = disk_bytenr;
+ em->bdev = root->fs_info->fs_devices->latest_bdev;
+ set_bit(EXTENT_FLAG_PINNED, &em->flags);
+ while (1) {
+ spin_lock(&em_tree->lock);
+ ret = add_extent_mapping(em_tree, em);
+ spin_unlock(&em_tree->lock);
+ if (ret != -EEXIST) {
+ free_extent_map(em);
+ break;
+ }
+ btrfs_drop_extent_cache(inode, em->start,
+ em->start + em->len - 1, 0);
+ }
+ type = BTRFS_ORDERED_PREALLOC;
+ } else {
+ type = BTRFS_ORDERED_NOCOW;
+ }
ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
- num_bytes, num_bytes,
- BTRFS_ORDERED_NOCOW);
+ num_bytes, num_bytes, type);
+ BUG_ON(ret);
+ extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
+ cur_offset, cur_offset + num_bytes - 1,
+ locked_page, 0, 0, 0);
cur_offset = extent_end;
if (cur_offset > end)
break;
@@ -745,7 +779,10 @@
if (btrfs_test_opt(root, NODATACOW) ||
btrfs_test_flag(inode, NODATACOW))
ret = run_delalloc_nocow(inode, locked_page, start, end,
- page_started);
+ page_started, 0);
+ else if (btrfs_test_flag(inode, PREALLOC))
+ ret = run_delalloc_nocow(inode, locked_page, start, end,
+ page_started, 1);
else
ret = cow_file_range(inode, locked_page, start, end,
page_started);
@@ -1006,6 +1043,63 @@
return -EAGAIN;
}
+static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
+ struct inode *inode, u64 file_pos,
+ u64 disk_bytenr, u64 disk_num_bytes,
+ u64 num_bytes, u64 ram_bytes,
+ u8 compression, u8 encryption,
+ u16 other_encoding, int extent_type)
+{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_key ins;
+ u64 hint;
+ int ret;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ ret = btrfs_drop_extents(trans, root, inode, file_pos,
+ file_pos + num_bytes, file_pos, &hint);
+ BUG_ON(ret);
+
+ ins.objectid = inode->i_ino;
+ ins.offset = file_pos;
+ ins.type = BTRFS_EXTENT_DATA_KEY;
+ ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
+ BUG_ON(ret);
+ leaf = path->nodes[0];
+ fi = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_generation(leaf, fi, trans->transid);
+ btrfs_set_file_extent_type(leaf, fi, extent_type);
+ btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
+ btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
+ btrfs_set_file_extent_offset(leaf, fi, 0);
+ btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
+ btrfs_set_file_extent_compression(leaf, fi, compression);
+ btrfs_set_file_extent_encryption(leaf, fi, encryption);
+ btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
+ btrfs_mark_buffer_dirty(leaf);
+
+ inode_add_bytes(inode, num_bytes);
+ btrfs_drop_extent_cache(inode, file_pos, file_pos + num_bytes - 1, 0);
+
+ ins.objectid = disk_bytenr;
+ ins.offset = disk_num_bytes;
+ ins.type = BTRFS_EXTENT_ITEM_KEY;
+ ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
+ root->root_key.objectid,
+ trans->transid, inode->i_ino, &ins);
+ BUG_ON(ret);
+
+ btrfs_free_path(path);
+ return 0;
+}
+
/* as ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
@@ -1016,12 +1110,7 @@
struct btrfs_trans_handle *trans;
struct btrfs_ordered_extent *ordered_extent;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
- struct btrfs_file_extent_item *extent_item;
- struct btrfs_path *path = NULL;
- struct extent_buffer *leaf;
- u64 alloc_hint = 0;
- struct list_head list;
- struct btrfs_key ins;
+ int compressed = 0;
int ret;
ret = btrfs_dec_test_ordered_pending(inode, start, end - start + 1);
@@ -1035,67 +1124,30 @@
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags))
goto nocow;
- path = btrfs_alloc_path();
- BUG_ON(!path);
-
lock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);
- INIT_LIST_HEAD(&list);
-
- ret = btrfs_drop_extents(trans, root, inode,
- ordered_extent->file_offset,
- ordered_extent->file_offset +
- ordered_extent->len,
- ordered_extent->file_offset, &alloc_hint);
- BUG_ON(ret);
-
- ins.objectid = inode->i_ino;
- ins.offset = ordered_extent->file_offset;
- ins.type = BTRFS_EXTENT_DATA_KEY;
- ret = btrfs_insert_empty_item(trans, root, path, &ins,
- sizeof(*extent_item));
- BUG_ON(ret);
- leaf = path->nodes[0];
- extent_item = btrfs_item_ptr(leaf, path->slots[0],
- struct btrfs_file_extent_item);
- btrfs_set_file_extent_generation(leaf, extent_item, trans->transid);
- btrfs_set_file_extent_type(leaf, extent_item, BTRFS_FILE_EXTENT_REG);
- btrfs_set_file_extent_disk_bytenr(leaf, extent_item,
- ordered_extent->start);
- btrfs_set_file_extent_disk_num_bytes(leaf, extent_item,
- ordered_extent->disk_len);
- btrfs_set_file_extent_offset(leaf, extent_item, 0);
-
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
- btrfs_set_file_extent_compression(leaf, extent_item, 1);
- else
- btrfs_set_file_extent_compression(leaf, extent_item, 0);
- btrfs_set_file_extent_encryption(leaf, extent_item, 0);
- btrfs_set_file_extent_other_encoding(leaf, extent_item, 0);
-
- /* ram bytes = extent_num_bytes for now */
- btrfs_set_file_extent_num_bytes(leaf, extent_item,
- ordered_extent->len);
- btrfs_set_file_extent_ram_bytes(leaf, extent_item,
- ordered_extent->len);
- btrfs_mark_buffer_dirty(leaf);
-
- btrfs_drop_extent_cache(inode, ordered_extent->file_offset,
- ordered_extent->file_offset +
- ordered_extent->len - 1, 0);
-
- ins.objectid = ordered_extent->start;
- ins.offset = ordered_extent->disk_len;
- ins.type = BTRFS_EXTENT_ITEM_KEY;
- ret = btrfs_alloc_reserved_extent(trans, root, leaf->start,
- root->root_key.objectid,
- trans->transid, inode->i_ino, &ins);
- BUG_ON(ret);
- btrfs_release_path(root, path);
-
- inode_add_bytes(inode, ordered_extent->len);
+ compressed = 1;
+ if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
+ BUG_ON(compressed);
+ ret = btrfs_mark_extent_written(trans, root, inode,
+ ordered_extent->file_offset,
+ ordered_extent->file_offset +
+ ordered_extent->len);
+ BUG_ON(ret);
+ } else {
+ ret = insert_reserved_file_extent(trans, inode,
+ ordered_extent->file_offset,
+ ordered_extent->start,
+ ordered_extent->disk_len,
+ ordered_extent->len,
+ ordered_extent->len,
+ compressed, 0, 0,
+ BTRFS_FILE_EXTENT_REG);
+ BUG_ON(ret);
+ }
unlock_extent(io_tree, ordered_extent->file_offset,
ordered_extent->file_offset + ordered_extent->len - 1,
GFP_NOFS);
@@ -1115,8 +1167,6 @@
btrfs_put_ordered_extent(ordered_extent);
btrfs_end_transaction(trans, root);
- if (path)
- btrfs_free_path(path);
return 0;
}
@@ -3488,7 +3538,8 @@
found_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
compressed = btrfs_file_extent_compression(leaf, item);
- if (found_type == BTRFS_FILE_EXTENT_REG) {
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
@@ -3521,7 +3572,8 @@
goto not_found_em;
}
- if (found_type == BTRFS_FILE_EXTENT_REG) {
+ if (found_type == BTRFS_FILE_EXTENT_REG ||
+ found_type == BTRFS_FILE_EXTENT_PREALLOC) {
em->start = extent_start;
em->len = extent_end - extent_start;
bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
@@ -3538,6 +3590,8 @@
bytenr += btrfs_file_extent_offset(leaf, item);
em->block_start = bytenr;
em->block_len = em->len;
+ if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
}
goto insert;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
@@ -3969,6 +4023,7 @@
if (error)
return error;
+ atomic_inc(&inode->i_count);
d_instantiate(dentry, inode);
return 0;
}
@@ -4318,6 +4373,7 @@
inode->i_op = &btrfs_symlink_inode_operations;
inode->i_mapping->a_ops = &btrfs_symlink_aops;
inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
+ inode_set_bytes(inode, name_len);
btrfs_i_size_write(inode, name_len - 1);
err = btrfs_update_inode(trans, root, inode);
if (err)
@@ -4335,6 +4391,130 @@
return err;
}
+static int prealloc_file_range(struct inode *inode, u64 start, u64 end,
+ u64 alloc_hint, int mode)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_key ins;
+ u64 alloc_size;
+ u64 cur_offset = start;
+ u64 num_bytes = end - start;
+ int ret = 0;
+
+ trans = btrfs_join_transaction(root, 1);
+ BUG_ON(!trans);
+ btrfs_set_trans_block_group(trans, inode);
+
+ while (num_bytes > 0) {
+ alloc_size = min(num_bytes, root->fs_info->max_extent);
+ ret = btrfs_reserve_extent(trans, root, alloc_size,
+ root->sectorsize, 0, alloc_hint,
+ (u64)-1, &ins, 1);
+ if (ret) {
+ WARN_ON(1);
+ goto out;
+ }
+ ret = insert_reserved_file_extent(trans, inode,
+ cur_offset, ins.objectid,
+ ins.offset, ins.offset,
+ ins.offset, 0, 0, 0,
+ BTRFS_FILE_EXTENT_PREALLOC);
+ BUG_ON(ret);
+ num_bytes -= ins.offset;
+ cur_offset += ins.offset;
+ alloc_hint = ins.objectid + ins.offset;
+ }
+out:
+ if (cur_offset > start) {
+ inode->i_ctime = CURRENT_TIME;
+ btrfs_set_flag(inode, PREALLOC);
+ if (!(mode & FALLOC_FL_KEEP_SIZE) &&
+ cur_offset > i_size_read(inode))
+ btrfs_i_size_write(inode, cur_offset);
+ ret = btrfs_update_inode(trans, root, inode);
+ BUG_ON(ret);
+ }
+
+ btrfs_end_transaction(trans, root);
+ return ret;
+}
+
+static long btrfs_fallocate(struct inode *inode, int mode,
+ loff_t offset, loff_t len)
+{
+ u64 cur_offset;
+ u64 last_byte;
+ u64 alloc_start;
+ u64 alloc_end;
+ u64 alloc_hint = 0;
+ u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
+ struct extent_map *em;
+ int ret;
+
+ alloc_start = offset & ~mask;
+ alloc_end = (offset + len + mask) & ~mask;
+
+ mutex_lock(&inode->i_mutex);
+ if (alloc_start > inode->i_size) {
+ ret = btrfs_cont_expand(inode, alloc_start);
+ if (ret)
+ goto out;
+ }
+
+ while (1) {
+ struct btrfs_ordered_extent *ordered;
+ lock_extent(&BTRFS_I(inode)->io_tree, alloc_start,
+ alloc_end - 1, GFP_NOFS);
+ ordered = btrfs_lookup_first_ordered_extent(inode,
+ alloc_end - 1);
+ if (ordered &&
+ ordered->file_offset + ordered->len > alloc_start &&
+ ordered->file_offset < alloc_end) {
+ btrfs_put_ordered_extent(ordered);
+ unlock_extent(&BTRFS_I(inode)->io_tree,
+ alloc_start, alloc_end - 1, GFP_NOFS);
+ btrfs_wait_ordered_range(inode, alloc_start,
+ alloc_end - alloc_start);
+ } else {
+ if (ordered)
+ btrfs_put_ordered_extent(ordered);
+ break;
+ }
+ }
+
+ cur_offset = alloc_start;
+ while (1) {
+ em = btrfs_get_extent(inode, NULL, 0, cur_offset,
+ alloc_end - cur_offset, 0);
+ BUG_ON(IS_ERR(em) || !em);
+ last_byte = min(extent_map_end(em), alloc_end);
+ last_byte = (last_byte + mask) & ~mask;
+ if (em->block_start == EXTENT_MAP_HOLE) {
+ ret = prealloc_file_range(inode, cur_offset,
+ last_byte, alloc_hint, mode);
+ if (ret < 0) {
+ free_extent_map(em);
+ break;
+ }
+ }
+ if (em->block_start <= EXTENT_MAP_LAST_BYTE)
+ alloc_hint = em->block_start;
+ free_extent_map(em);
+
+ cur_offset = last_byte;
+ if (cur_offset >= alloc_end) {
+ ret = 0;
+ break;
+ }
+ }
+ unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, alloc_end - 1,
+ GFP_NOFS);
+out:
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
@@ -4421,6 +4601,7 @@
.listxattr = btrfs_listxattr,
.removexattr = btrfs_removexattr,
.permission = btrfs_permission,
+ .fallocate = btrfs_fallocate,
};
static struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,