[patch 28/35 code-cleanup] reiserfs: cleanup path functions

From: Jeff Mahoney
Date: Mon Mar 30 2009 - 14:26:07 EST


This patch cleans up some redundancies in the reiserfs tree path code.

decrement_bcount() is essentially the same function as brelse(), so we use
that instead.

decrement_counters_in_path() is exactly the same function as pathrelse(), so
we kill that and use pathrelse() instead.

There's also a bit of cleanup that makes the code a bit more readable.

Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>

---

fs/reiserfs/fix_node.c | 58 ++++++++++++++++++++++++------------------------
fs/reiserfs/stree.c | 59 ++++++++++---------------------------------------
2 files changed, 43 insertions(+), 74 deletions(-)

--- a/fs/reiserfs/fix_node.c
+++ b/fs/reiserfs/fix_node.c
@@ -753,20 +753,21 @@ static void free_buffers_in_tb(struct tr
{
int n_counter;

- decrement_counters_in_path(p_s_tb->tb_path);
+ pathrelse(p_s_tb->tb_path);

for (n_counter = 0; n_counter < MAX_HEIGHT; n_counter++) {
- decrement_bcount(p_s_tb->L[n_counter]);
+ brelse(p_s_tb->L[n_counter]);
+ brelse(p_s_tb->R[n_counter]);
+ brelse(p_s_tb->FL[n_counter]);
+ brelse(p_s_tb->FR[n_counter]);
+ brelse(p_s_tb->CFL[n_counter]);
+ brelse(p_s_tb->CFR[n_counter]);
+
p_s_tb->L[n_counter] = NULL;
- decrement_bcount(p_s_tb->R[n_counter]);
p_s_tb->R[n_counter] = NULL;
- decrement_bcount(p_s_tb->FL[n_counter]);
p_s_tb->FL[n_counter] = NULL;
- decrement_bcount(p_s_tb->FR[n_counter]);
p_s_tb->FR[n_counter] = NULL;
- decrement_bcount(p_s_tb->CFL[n_counter]);
p_s_tb->CFL[n_counter] = NULL;
- decrement_bcount(p_s_tb->CFR[n_counter]);
p_s_tb->CFR[n_counter] = NULL;
}
}
@@ -1022,7 +1023,7 @@ static int get_far_parent(struct tree_ba
if (buffer_locked(*pp_s_com_father)) {
__wait_on_buffer(*pp_s_com_father);
if (FILESYSTEM_CHANGED_TB(p_s_tb)) {
- decrement_bcount(*pp_s_com_father);
+ brelse(*pp_s_com_father);
return REPEAT_SEARCH;
}
}
@@ -1050,8 +1051,8 @@ static int get_far_parent(struct tree_ba
return IO_ERROR;

if (FILESYSTEM_CHANGED_TB(p_s_tb)) {
- decrement_counters_in_path(&s_path_to_neighbor_father);
- decrement_bcount(*pp_s_com_father);
+ pathrelse(&s_path_to_neighbor_father);
+ brelse(*pp_s_com_father);
return REPEAT_SEARCH;
}

@@ -1063,7 +1064,7 @@ static int get_far_parent(struct tree_ba
FIRST_PATH_ELEMENT_OFFSET, "PAP-8192: path length is too small");

s_path_to_neighbor_father.path_length--;
- decrement_counters_in_path(&s_path_to_neighbor_father);
+ pathrelse(&s_path_to_neighbor_father);
return CARRY_ON;
}

@@ -1086,10 +1087,10 @@ static int get_parents(struct tree_balan
if (n_path_offset <= FIRST_PATH_ELEMENT_OFFSET) {
/* The root can not have parents.
Release nodes which previously were obtained as parents of the current node neighbors. */
- decrement_bcount(p_s_tb->FL[n_h]);
- decrement_bcount(p_s_tb->CFL[n_h]);
- decrement_bcount(p_s_tb->FR[n_h]);
- decrement_bcount(p_s_tb->CFR[n_h]);
+ brelse(p_s_tb->FL[n_h]);
+ brelse(p_s_tb->CFL[n_h]);
+ brelse(p_s_tb->FR[n_h]);
+ brelse(p_s_tb->CFR[n_h]);
p_s_tb->FL[n_h] = p_s_tb->CFL[n_h] = p_s_tb->FR[n_h] =
p_s_tb->CFR[n_h] = NULL;
return CARRY_ON;
@@ -1115,9 +1116,9 @@ static int get_parents(struct tree_balan
return n_ret_value;
}

- decrement_bcount(p_s_tb->FL[n_h]);
+ brelse(p_s_tb->FL[n_h]);
p_s_tb->FL[n_h] = p_s_curf; /* New initialization of FL[n_h]. */
- decrement_bcount(p_s_tb->CFL[n_h]);
+ brelse(p_s_tb->CFL[n_h]);
p_s_tb->CFL[n_h] = p_s_curcf; /* New initialization of CFL[n_h]. */

RFALSE((p_s_curf && !B_IS_IN_TREE(p_s_curf)) ||
@@ -1145,10 +1146,10 @@ static int get_parents(struct tree_balan
p_s_tb->rkey[n_h] = n_position;
}

- decrement_bcount(p_s_tb->FR[n_h]);
+ brelse(p_s_tb->FR[n_h]);
p_s_tb->FR[n_h] = p_s_curf; /* New initialization of FR[n_path_offset]. */

- decrement_bcount(p_s_tb->CFR[n_h]);
+ brelse(p_s_tb->CFR[n_h]);
p_s_tb->CFR[n_h] = p_s_curcf; /* New initialization of CFR[n_path_offset]. */

RFALSE((p_s_curf && !B_IS_IN_TREE(p_s_curf)) ||
@@ -1964,7 +1965,7 @@ static int get_neighbors(struct tree_bal
if (!p_s_bh)
return IO_ERROR;
if (FILESYSTEM_CHANGED_TB(p_s_tb)) {
- decrement_bcount(p_s_bh);
+ brelse(p_s_bh);
PROC_INFO_INC(p_s_sb, get_neighbors_restart[n_h]);
return REPEAT_SEARCH;
}
@@ -1980,7 +1981,7 @@ static int get_neighbors(struct tree_bal
dc_size(B_N_CHILD(p_s_tb->FL[0], n_child_position)),
"PAP-8290: invalid child size of left neighbor");

- decrement_bcount(p_s_tb->L[n_h]);
+ brelse(p_s_tb->L[n_h]);
p_s_tb->L[n_h] = p_s_bh;
}

@@ -2001,11 +2002,11 @@ static int get_neighbors(struct tree_bal
if (!p_s_bh)
return IO_ERROR;
if (FILESYSTEM_CHANGED_TB(p_s_tb)) {
- decrement_bcount(p_s_bh);
+ brelse(p_s_bh);
PROC_INFO_INC(p_s_sb, get_neighbors_restart[n_h]);
return REPEAT_SEARCH;
}
- decrement_bcount(p_s_tb->R[n_h]);
+ brelse(p_s_tb->R[n_h]);
p_s_tb->R[n_h] = p_s_bh;

RFALSE(!n_h
@@ -2511,16 +2512,17 @@ int fix_nodes(int n_op_mode, struct tree
}

brelse(p_s_tb->L[i]);
- p_s_tb->L[i] = NULL;
brelse(p_s_tb->R[i]);
- p_s_tb->R[i] = NULL;
brelse(p_s_tb->FL[i]);
- p_s_tb->FL[i] = NULL;
brelse(p_s_tb->FR[i]);
- p_s_tb->FR[i] = NULL;
brelse(p_s_tb->CFL[i]);
- p_s_tb->CFL[i] = NULL;
brelse(p_s_tb->CFR[i]);
+
+ p_s_tb->L[i] = NULL;
+ p_s_tb->R[i] = NULL;
+ p_s_tb->FL[i] = NULL;
+ p_s_tb->FR[i] = NULL;
+ p_s_tb->CFL[i] = NULL;
p_s_tb->CFR[i] = NULL;
}

--- a/fs/reiserfs/stree.c
+++ b/fs/reiserfs/stree.c
@@ -23,7 +23,6 @@
* get_rkey
* key_in_buffer
* decrement_bcount
- * decrement_counters_in_path
* reiserfs_check_path
* pathrelse_and_restore
* pathrelse
@@ -359,36 +358,6 @@ static inline int key_in_buffer(struct t
return 1;
}

-inline void decrement_bcount(struct buffer_head *p_s_bh)
-{
- if (p_s_bh) {
- if (atomic_read(&(p_s_bh->b_count))) {
- put_bh(p_s_bh);
- return;
- }
- reiserfs_panic(NULL, "PAP-5070",
- "trying to free free buffer %b", p_s_bh);
- }
-}
-
-/* Decrement b_count field of the all buffers in the path. */
-void decrement_counters_in_path(struct treepath *p_s_search_path)
-{
- int n_path_offset = p_s_search_path->path_length;
-
- RFALSE(n_path_offset < ILLEGAL_PATH_ELEMENT_OFFSET ||
- n_path_offset > EXTENDED_MAX_HEIGHT - 1,
- "PAP-5080: invalid path offset of %d", n_path_offset);
-
- while (n_path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) {
- struct buffer_head *bh;
-
- bh = PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--);
- decrement_bcount(bh);
- }
- p_s_search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
-}
-
int reiserfs_check_path(struct treepath *p)
{
RFALSE(p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET,
@@ -396,12 +365,11 @@ int reiserfs_check_path(struct treepath
return 0;
}

-/* Release all buffers in the path. Restore dirty bits clean
-** when preparing the buffer for the log
-**
-** only called from fix_nodes()
-*/
-void pathrelse_and_restore(struct super_block *s, struct treepath *p_s_search_path)
+/* Drop the reference to each buffer in a path and restore
+ * dirty bits clean when preparing the buffer for the log.
+ * This version should only be called from fix_nodes() */
+void pathrelse_and_restore(struct super_block *sb,
+ struct treepath *p_s_search_path)
{
int n_path_offset = p_s_search_path->path_length;

@@ -409,16 +377,15 @@ void pathrelse_and_restore(struct super_
"clm-4000: invalid path offset");

while (n_path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) {
- reiserfs_restore_prepared_buffer(s,
- PATH_OFFSET_PBUFFER
- (p_s_search_path,
- n_path_offset));
- brelse(PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--));
+ struct buffer_head *bh;
+ bh = PATH_OFFSET_PBUFFER(p_s_search_path, n_path_offset--);
+ reiserfs_restore_prepared_buffer(sb, bh);
+ brelse(bh);
}
p_s_search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
}

-/* Release all buffers in the path. */
+/* Drop the reference to each buffer in a path */
void pathrelse(struct treepath *p_s_search_path)
{
int n_path_offset = p_s_search_path->path_length;
@@ -631,7 +598,7 @@ int search_by_key(struct super_block *p_
we must be careful to release all nodes in a path before we either
discard the path struct or re-use the path struct, as we do here. */

- decrement_counters_in_path(p_s_search_path);
+ pathrelse(p_s_search_path);

right_neighbor_of_leaf_node = 0;

@@ -691,7 +658,7 @@ int search_by_key(struct super_block *p_
PROC_INFO_INC(p_s_sb, search_by_key_restarted);
PROC_INFO_INC(p_s_sb,
sbk_restarted[expected_level - 1]);
- decrement_counters_in_path(p_s_search_path);
+ pathrelse(p_s_search_path);

/* Get the root block number so that we can repeat the search
starting from the root. */
@@ -1868,7 +1835,7 @@ int reiserfs_do_truncate(struct reiserfs
if (journal_transaction_should_end(th, 0) ||
reiserfs_transaction_free_space(th) <= JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD) {
int orig_len_alloc = th->t_blocks_allocated;
- decrement_counters_in_path(&s_search_path);
+ pathrelse(&s_search_path);

if (update_timestamps) {
p_s_inode->i_mtime = p_s_inode->i_ctime =


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