reiserfs: locking, release lock around quota operations

Previous commits released the write lock across quota operations but
missed several places.  In particular, the free operations can also
call into the file system code and take the write lock, causing
deadlocks.

This patch introduces some more helpers and uses them for quota call
sites.  Without this patch applied, reiserfs + quotas runs into deadlocks
under anything more than trivial load.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
index 4d7d476d7bff..b14706a05d52 100644
--- a/fs/reiserfs/stree.c
+++ b/fs/reiserfs/stree.c
@@ -1186,6 +1186,7 @@ int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
         struct item_head *q_ih;
         int quota_cut_bytes;
         int ret_value, del_size, removed;
+        int depth;
 
 #ifdef CONFIG_REISERFS_CHECK
         char mode;
@@ -1295,7 +1296,9 @@ int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
                        "reiserquota delete_item(): freeing %u, id=%u type=%c",
                        quota_cut_bytes, inode->i_uid, head2type(&s_ih));
 #endif
+        depth = reiserfs_write_unlock_nested(inode->i_sb);
         dquot_free_space_nodirty(inode, quota_cut_bytes);
+        reiserfs_write_lock_nested(inode->i_sb, depth);
 
         /* Return deleted body length */
         return ret_value;
@@ -1321,6 +1324,7 @@ int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
 void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
                                 struct inode *inode, struct reiserfs_key *key)
 {
+        struct super_block *sb = th->t_super;
         struct tree_balance tb;
         INITIALIZE_PATH(path);
         int item_len = 0;
@@ -1373,14 +1377,17 @@ void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
                 if (retval == CARRY_ON) {
                         do_balance(&tb, NULL, NULL, M_DELETE);
                         if (inode) {    /* Should we count quota for item? (we don't count quotas for save-links) */
+                                int depth;
 #ifdef REISERQUOTA_DEBUG
                                 reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
                                                "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
                                                quota_cut_bytes, inode->i_uid,
                                                key2type(key));
 #endif
+                                depth = reiserfs_write_unlock_nested(sb);
                                 dquot_free_space_nodirty(inode,
                                                          quota_cut_bytes);
+                                reiserfs_write_lock_nested(sb, depth);
                         }
                         break;
                 }
@@ -1557,6 +1564,7 @@ int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
         int retval2 = -1;
         int quota_cut_bytes;
         loff_t tail_pos = 0;
+        int depth;
 
         BUG_ON(!th->t_trans_id);
 
@@ -1729,7 +1737,9 @@ int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
                        "reiserquota cut_from_item(): freeing %u id=%u type=%c",
                        quota_cut_bytes, inode->i_uid, '?');
 #endif
+        depth = reiserfs_write_unlock_nested(sb);
         dquot_free_space_nodirty(inode, quota_cut_bytes);
+        reiserfs_write_lock_nested(sb, depth);
         return ret_value;
 }
 
@@ -1949,9 +1959,11 @@ int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th, struct tree
                              const char *body,  /* Pointer to the bytes to paste.    */
                              int pasted_size)
 {                               /* Size of pasted bytes.             */
+        struct super_block *sb = inode->i_sb;
         struct tree_balance s_paste_balance;
         int retval;
         int fs_gen;
+        int depth;
 
         BUG_ON(!th->t_trans_id);
 
@@ -1964,9 +1976,9 @@ int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th, struct tree
                        key2type(&(key->on_disk_key)));
 #endif
 
-        reiserfs_write_unlock(inode->i_sb);
+        depth = reiserfs_write_unlock_nested(sb);
         retval = dquot_alloc_space_nodirty(inode, pasted_size);
-        reiserfs_write_lock(inode->i_sb);
+        reiserfs_write_lock_nested(sb, depth);
         if (retval) {
                 pathrelse(search_path);
                 return retval;
@@ -2023,7 +2035,9 @@ int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th, struct tree
                        pasted_size, inode->i_uid,
                        key2type(&(key->on_disk_key)));
 #endif
+        depth = reiserfs_write_unlock_nested(sb);
         dquot_free_space_nodirty(inode, pasted_size);
+        reiserfs_write_lock_nested(sb, depth);
         return retval;
 }
 
@@ -2046,6 +2060,7 @@ int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
         BUG_ON(!th->t_trans_id);
 
         if (inode) {            /* Do we count quotas for item? */
+                int depth;
                 fs_gen = get_generation(inode->i_sb);
                 quota_bytes = ih_item_len(ih);
 
@@ -2059,11 +2074,11 @@ int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
                                "reiserquota insert_item(): allocating %u id=%u type=%c",
                                quota_bytes, inode->i_uid, head2type(ih));
 #endif
-                reiserfs_write_unlock(inode->i_sb);
                 /* We can't dirty inode here. It would be immediately written but
                  * appropriate stat item isn't inserted yet... */
+                depth = reiserfs_write_unlock_nested(inode->i_sb);
                 retval = dquot_alloc_space_nodirty(inode, quota_bytes);
-                reiserfs_write_lock(inode->i_sb);
+                reiserfs_write_lock_nested(inode->i_sb, depth);
                 if (retval) {
                         pathrelse(path);
                         return retval;
@@ -2114,7 +2129,10 @@ int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
                        "reiserquota insert_item(): freeing %u id=%u type=%c",
                        quota_bytes, inode->i_uid, head2type(ih));
 #endif
-        if (inode)
+        if (inode) {
+                int depth = reiserfs_write_unlock_nested(inode->i_sb);
                 dquot_free_space_nodirty(inode, quota_bytes);
+                reiserfs_write_lock_nested(inode->i_sb, depth);
+        }
         return retval;
 }