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authorEric Whitney <enwlinux@gmail.com>2020-05-10 11:58:05 -0400
committerTheodore Ts'o <tytso@mit.edu>2020-06-03 23:16:53 -0400
commit8ad8d710035edf8d14f8ecc5fa15f8e1a27ecb59 (patch)
tree1e34597a68d9451c841b7f80fa0e3cc9093fce28 /fs/ext4
parent70aa1554b01474ab08d08e5a18b0215a7ff1e8dc (diff)
ext4: rework map struct instantiation in ext4_ext_map_blocks()
The path performing block allocations in ext4_ext_map_blocks() contains code trimming the length of a new extent that is repeated later in the function. This code is both redundant and unnecessary as the exact length of the new extent has already been calculated. Rewrite the instantiation of the map struct in this case to use the available values, avoiding the overhead of unnecessary conversions and improving clarity. Add another map struct instantiation tailored specifically to the separate case for an existing written extent. Remove an old comment that no longer appears applicable to the current code. Signed-off-by: Eric Whitney <enwlinux@gmail.com> Link: https://lore.kernel.org/r/20200510155805.18808-1-enwlinux@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Diffstat (limited to 'fs/ext4')
-rw-r--r--fs/ext4/extents.c50
1 files changed, 25 insertions, 25 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 969f4c030cf0..ce394706c61a 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4045,7 +4045,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path = NULL;
struct ext4_extent newex, *ex, *ex2;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- ext4_fsblk_t newblock = 0;
+ ext4_fsblk_t newblock = 0, pblk;
int err = 0, depth, ret;
unsigned int allocated = 0, offset = 0;
unsigned int allocated_clusters = 0;
@@ -4060,7 +4060,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
if (IS_ERR(path)) {
err = PTR_ERR(path);
path = NULL;
- goto out2;
+ goto out;
}
depth = ext_depth(inode);
@@ -4076,7 +4076,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
(unsigned long) map->m_lblk, depth,
path[depth].p_block);
err = -EFSCORRUPTED;
- goto out2;
+ goto out;
}
ex = path[depth].p_ext;
@@ -4110,8 +4110,14 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
err = convert_initialized_extent(handle,
inode, map, &path, &allocated);
- goto out2;
+ goto out;
} else if (!ext4_ext_is_unwritten(ex)) {
+ map->m_flags |= EXT4_MAP_MAPPED;
+ map->m_pblk = newblock;
+ if (allocated > map->m_len)
+ allocated = map->m_len;
+ map->m_len = allocated;
+ ext4_ext_show_leaf(inode, path);
goto out;
}
@@ -4122,7 +4128,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
err = ret;
else
allocated = ret;
- goto out2;
+ goto out;
}
}
@@ -4147,7 +4153,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
map->m_pblk = 0;
map->m_len = min_t(unsigned int, map->m_len, hole_len);
- goto out2;
+ goto out;
}
/*
@@ -4171,12 +4177,12 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ar.lleft = map->m_lblk;
err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
if (err)
- goto out2;
+ goto out;
ar.lright = map->m_lblk;
ex2 = NULL;
err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
if (err)
- goto out2;
+ goto out;
/* Check if the extent after searching to the right implies a
* cluster we can use. */
@@ -4237,7 +4243,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
ar.flags |= EXT4_MB_USE_RESERVED;
newblock = ext4_mb_new_blocks(handle, &ar, &err);
if (!newblock)
- goto out2;
+ goto out;
allocated_clusters = ar.len;
ar.len = EXT4_C2B(sbi, ar.len) - offset;
ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
@@ -4247,7 +4253,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
got_allocated_blocks:
/* try to insert new extent into found leaf and return */
- ext4_ext_store_pblock(&newex, newblock + offset);
+ pblk = newblock + offset;
+ ext4_ext_store_pblock(&newex, pblk);
newex.ee_len = cpu_to_le16(ar.len);
/* Mark unwritten */
if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
@@ -4272,16 +4279,9 @@ got_allocated_blocks:
EXT4_C2B(sbi, allocated_clusters),
fb_flags);
}
- goto out2;
+ goto out;
}
- /* previous routine could use block we allocated */
- newblock = ext4_ext_pblock(&newex);
- allocated = ext4_ext_get_actual_len(&newex);
- if (allocated > map->m_len)
- allocated = map->m_len;
- map->m_flags |= EXT4_MAP_NEW;
-
/*
* Reduce the reserved cluster count to reflect successful deferred
* allocation of delayed allocated clusters or direct allocation of
@@ -4327,14 +4327,14 @@ got_allocated_blocks:
ext4_update_inode_fsync_trans(handle, inode, 1);
else
ext4_update_inode_fsync_trans(handle, inode, 0);
-out:
- if (allocated > map->m_len)
- allocated = map->m_len;
+
+ map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
+ map->m_pblk = pblk;
+ map->m_len = ar.len;
+ allocated = map->m_len;
ext4_ext_show_leaf(inode, path);
- map->m_flags |= EXT4_MAP_MAPPED;
- map->m_pblk = newblock;
- map->m_len = allocated;
-out2:
+
+out:
ext4_ext_drop_refs(path);
kfree(path);