Merge branch 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing

* 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: (31 commits)
  kill-the-bkl/reiserfs: turn GFP_ATOMIC flag to GFP_NOFS in reiserfs_get_block()
  kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create_0()
  kill-the-bkl/reiserfs: definitely drop the bkl from reiserfs_ioctl()
  kill-the-bkl/reiserfs: always lock the ioctl path
  kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependency
  kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependency
  kill-the-bkl/reiserfs: panic in case of lock imbalance
  kill-the-bkl/reiserfs: fix recursive reiserfs write lock in reiserfs_commit_write()
  kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir()
  kill-the-bkl/reiserfs: fix "reiserfs lock" / "inode mutex" lock inversion dependency
  kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblock
  kill-the-bkl/reiserfs: acquire the inode mutex safely
  kill-the-bkl/reiserfs: unlock only when needed in search_by_key
  kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safe
  kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end()
  kill-the-bkl/reiserfs: reduce number of contentions in search_by_key()
  kill-the-bkl/reiserfs: don't hold the write recursively in reiserfs_lookup()
  kill-the-bkl/reiserfs: lock only once on reiserfs_get_block()
  kill-the-bkl/reiserfs: conditionaly release the write lock on fs_changed()
  kill-the-BKL/reiserfs: add reiserfs_cond_resched()
  ...

16 files changed, 420 insertions, 163 deletions

diff --git a/fs/reiserfs/Makefile b/fs/reiserfs/Makefile
index 7c5ab6330dd6..6a9e30c041dd 100644
--- a/fs/reiserfs/Makefile
+++ b/fs/reiserfs/Makefile
@@ -7,7 +7,7 @@ obj-$(CONFIG_REISERFS_FS) += reiserfs.o
 reiserfs-objs := bitmap.o do_balan.o namei.o inode.o file.o dir.o fix_node.o \
                  super.o prints.o objectid.o lbalance.o ibalance.o stree.o \
                  hashes.o tail_conversion.o journal.o resize.o \
-                 item_ops.o ioctl.o procfs.o xattr.o
+                 item_ops.o ioctl.o procfs.o xattr.o lock.o
 
 ifeq ($(CONFIG_REISERFS_FS_XATTR),y)
 reiserfs-objs += xattr_user.o xattr_trusted.o
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index e716161ab325..685495707181 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -1249,14 +1249,18 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb,
         else if (bitmap == 0)
                 block = (REISERFS_DISK_OFFSET_IN_BYTES >> sb->s_blocksize_bits) + 1;
 
+        reiserfs_write_unlock(sb);
         bh = sb_bread(sb, block);
+        reiserfs_write_lock(sb);
         if (bh == NULL)
                 reiserfs_warning(sb, "sh-2029: %s: bitmap block (#%u) "
                                  "reading failed", __func__, block);
         else {
                 if (buffer_locked(bh)) {
                         PROC_INFO_INC(sb, scan_bitmap.wait);
+                        reiserfs_write_unlock(sb);
                         __wait_on_buffer(bh);
+                        reiserfs_write_lock(sb);
                 }
                 BUG_ON(!buffer_uptodate(bh));
                 BUG_ON(atomic_read(&bh->b_count) == 0);
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c
index 6d2668fdc384..c094f58c7448 100644
--- a/fs/reiserfs/dir.c
+++ b/fs/reiserfs/dir.c
@@ -20,7 +20,7 @@ const struct file_operations reiserfs_dir_operations = {
         .read = generic_read_dir,
         .readdir = reiserfs_readdir,
         .fsync = reiserfs_dir_fsync,
-        .ioctl = reiserfs_ioctl,
+        .unlocked_ioctl = reiserfs_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl = reiserfs_compat_ioctl,
 #endif
@@ -174,14 +174,22 @@ int reiserfs_readdir_dentry(struct dentry *dentry, void *dirent,
                                 // user space buffer is swapped out. At that time
                                 // entry can move to somewhere else
                                 memcpy(local_buf, d_name, d_reclen);
+
+                                /*
+                                 * Since filldir might sleep, we can release
+                                 * the write lock here for other waiters
+                                 */
+                                reiserfs_write_unlock(inode->i_sb);
                                 if (filldir
                                     (dirent, local_buf, d_reclen, d_off, d_ino,
                                      DT_UNKNOWN) < 0) {
+                                        reiserfs_write_lock(inode->i_sb);
                                         if (local_buf != small_buf) {
                                                 kfree(local_buf);
                                         }
                                         goto end;
                                 }
+                                reiserfs_write_lock(inode->i_sb);
                                 if (local_buf != small_buf) {
                                         kfree(local_buf);
                                 }
diff --git a/fs/reiserfs/do_balan.c b/fs/reiserfs/do_balan.c
index 128d3f7c8aa5..60c080440661 100644
--- a/fs/reiserfs/do_balan.c
+++ b/fs/reiserfs/do_balan.c
@@ -21,14 +21,6 @@
 #include <linux/buffer_head.h>
 #include <linux/kernel.h>
 
-#ifdef CONFIG_REISERFS_CHECK
-
-struct tree_balance *cur_tb = NULL;     /* detects whether more than one
-                                           copy of tb exists as a means
-                                           of checking whether schedule
-                                           is interrupting do_balance */
-#endif
-
 static inline void buffer_info_init_left(struct tree_balance *tb,
                                          struct buffer_info *bi)
 {
@@ -1840,11 +1832,12 @@ static int check_before_balancing(struct tree_balance *tb)
 {
         int retval = 0;
 
-        if (cur_tb) {
+        if (REISERFS_SB(tb->tb_sb)->cur_tb) {
                 reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
                                "occurred based on cur_tb not being null at "
                                "this point in code. do_balance cannot properly "
-                               "handle schedule occurring while it runs.");
+                               "handle concurrent tree accesses on a same "
+                               "mount point.");
         }
 
         /* double check that buffers that we will modify are unlocked. (fix_nodes should already have
@@ -1986,7 +1979,7 @@ static inline void do_balance_starts(struct tree_balance *tb)
              "check");*/
         RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
 #ifdef CONFIG_REISERFS_CHECK
-        cur_tb = tb;
+        REISERFS_SB(tb->tb_sb)->cur_tb = tb;
 #endif
 }
 
@@ -1996,7 +1989,7 @@ static inline void do_balance_completed(struct tree_balance *tb)
 #ifdef CONFIG_REISERFS_CHECK
         check_leaf_level(tb);
         check_internal_levels(tb);
-        cur_tb = NULL;
+        REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
 #endif
 
         /* reiserfs_free_block is no longer schedule safe.  So, we need to
diff --git a/fs/reiserfs/file.c b/fs/reiserfs/file.c
index 9f436668b7f8..da2dba082e2d 100644
--- a/fs/reiserfs/file.c
+++ b/fs/reiserfs/file.c
@@ -284,7 +284,7 @@ static ssize_t reiserfs_file_write(struct file *file,	/* the file we are going t
 const struct file_operations reiserfs_file_operations = {
         .read = do_sync_read,
         .write = reiserfs_file_write,
-        .ioctl = reiserfs_ioctl,
+        .unlocked_ioctl = reiserfs_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl = reiserfs_compat_ioctl,
 #endif
diff --git a/fs/reiserfs/fix_node.c b/fs/reiserfs/fix_node.c
index 5e5a4e6fbaf8..d2f31330dcae 100644
--- a/fs/reiserfs/fix_node.c
+++ b/fs/reiserfs/fix_node.c
@@ -563,9 +563,6 @@ static int get_num_ver(int mode, struct tree_balance *tb, int h,
         return needed_nodes;
 }
 
-#ifdef CONFIG_REISERFS_CHECK
-extern struct tree_balance *cur_tb;
-#endif
 
 /* Set parameters for balancing.
  * Performs write of results of analysis of balancing into structure tb,
@@ -1022,7 +1019,11 @@ static int get_far_parent(struct tree_balance *tb,
         /* Check whether the common parent is locked. */
 
         if (buffer_locked(*pcom_father)) {
+
+                /* Release the write lock while the buffer is busy */
+                reiserfs_write_unlock(tb->tb_sb);
                 __wait_on_buffer(*pcom_father);
+                reiserfs_write_lock(tb->tb_sb);
                 if (FILESYSTEM_CHANGED_TB(tb)) {
                         brelse(*pcom_father);
                         return REPEAT_SEARCH;
@@ -1927,7 +1928,9 @@ static int get_direct_parent(struct tree_balance *tb, int h)
                 return REPEAT_SEARCH;
 
         if (buffer_locked(bh)) {
+                reiserfs_write_unlock(tb->tb_sb);
                 __wait_on_buffer(bh);
+                reiserfs_write_lock(tb->tb_sb);
                 if (FILESYSTEM_CHANGED_TB(tb))
                         return REPEAT_SEARCH;
         }
@@ -1965,7 +1968,9 @@ static int get_neighbors(struct tree_balance *tb, int h)
                      tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->
                                                                        FL[h]);
                 son_number = B_N_CHILD_NUM(tb->FL[h], child_position);
+                reiserfs_write_unlock(sb);
                 bh = sb_bread(sb, son_number);
+                reiserfs_write_lock(sb);
                 if (!bh)
                         return IO_ERROR;
                 if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2003,7 +2008,9 @@ static int get_neighbors(struct tree_balance *tb, int h)
                 child_position =
                     (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;
                 son_number = B_N_CHILD_NUM(tb->FR[h], child_position);
+                reiserfs_write_unlock(sb);
                 bh = sb_bread(sb, son_number);
+                reiserfs_write_lock(sb);
                 if (!bh)
                         return IO_ERROR;
                 if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2278,7 +2285,9 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb)
                                     REPEAT_SEARCH : CARRY_ON;
                         }
 #endif
+                        reiserfs_write_unlock(tb->tb_sb);
                         __wait_on_buffer(locked);
+                        reiserfs_write_lock(tb->tb_sb);
                         if (FILESYSTEM_CHANGED_TB(tb))
                                 return REPEAT_SEARCH;
                 }
@@ -2349,12 +2358,14 @@ int fix_nodes(int op_mode, struct tree_balance *tb,
 
         /* if it possible in indirect_to_direct conversion */
         if (buffer_locked(tbS0)) {
+                reiserfs_write_unlock(tb->tb_sb);
                 __wait_on_buffer(tbS0);
+                reiserfs_write_lock(tb->tb_sb);
                 if (FILESYSTEM_CHANGED_TB(tb))
                         return REPEAT_SEARCH;
         }
 #ifdef CONFIG_REISERFS_CHECK
-        if (cur_tb) {
+        if (REISERFS_SB(tb->tb_sb)->cur_tb) {
                 print_cur_tb("fix_nodes");
                 reiserfs_panic(tb->tb_sb, "PAP-8305",
                                "there is pending do_balance");
diff --git a/fs/reiserfs/inode.c b/fs/reiserfs/inode.c
index a14d6cd9eeda..3a28e7751b3c 100644
--- a/fs/reiserfs/inode.c
+++ b/fs/reiserfs/inode.c
@@ -251,7 +251,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
         struct cpu_key key;
         struct buffer_head *bh;
         struct item_head *ih, tmp_ih;
-        int fs_gen;
         b_blocknr_t blocknr;
         char *p = NULL;
         int chars;
@@ -265,7 +264,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
                      (loff_t) block * inode->i_sb->s_blocksize + 1, TYPE_ANY,
                      3);
 
-      research:
         result = search_for_position_by_key(inode->i_sb, &key, &path);
         if (result != POSITION_FOUND) {
                 pathrelse(&path);
@@ -340,7 +338,6 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
         }
         // read file tail into part of page
         offset = (cpu_key_k_offset(&key) - 1) & (PAGE_CACHE_SIZE - 1);
-        fs_gen = get_generation(inode->i_sb);
         copy_item_head(&tmp_ih, ih);
 
         /* we only want to kmap if we are reading the tail into the page.
@@ -348,13 +345,9 @@ static int _get_block_create_0(struct inode *inode, sector_t block,
          ** sure we need to.  But, this means the item might move if
          ** kmap schedules
          */
-        if (!p) {
+        if (!p)
                 p = (char *)kmap(bh_result->b_page);
-                if (fs_changed(fs_gen, inode->i_sb)
-                    && item_moved(&tmp_ih, &path)) {
-                        goto research;
-                }
-        }
+
         p += offset;
         memset(p, 0, inode->i_sb->s_blocksize);
         do {
@@ -489,10 +482,14 @@ static int reiserfs_get_blocks_direct_io(struct inode *inode,
            disappeared */
         if (REISERFS_I(inode)->i_flags & i_pack_on_close_mask) {
                 int err;
-                lock_kernel();
+
+                reiserfs_write_lock(inode->i_sb);
+
                 err = reiserfs_commit_for_inode(inode);
                 REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
-                unlock_kernel();
+
+                reiserfs_write_unlock(inode->i_sb);
+
                 if (err < 0)
                         ret = err;
         }
@@ -601,6 +598,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
         __le32 *item;
         int done;
         int fs_gen;
+        int lock_depth;
         struct reiserfs_transaction_handle *th = NULL;
         /* space reserved in transaction batch:
            . 3 balancings in direct->indirect conversion
@@ -616,12 +614,11 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
         loff_t new_offset =
             (((loff_t) block) << inode->i_sb->s_blocksize_bits) + 1;
 
-        /* bad.... */
-        reiserfs_write_lock(inode->i_sb);
+        lock_depth = reiserfs_write_lock_once(inode->i_sb);
         version = get_inode_item_key_version(inode);
 
         if (!file_capable(inode, block)) {
-                reiserfs_write_unlock(inode->i_sb);
+                reiserfs_write_unlock_once(inode->i_sb, lock_depth);
                 return -EFBIG;
         }
 
@@ -633,7 +630,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
                 /* find number of block-th logical block of the file */
                 ret = _get_block_create_0(inode, block, bh_result,
                                           create | GET_BLOCK_READ_DIRECT);
-                reiserfs_write_unlock(inode->i_sb);
+                reiserfs_write_unlock_once(inode->i_sb, lock_depth);
                 return ret;
         }
         /*
@@ -751,7 +748,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
                 if (!dangle && th)
                         retval = reiserfs_end_persistent_transaction(th);
 
-                reiserfs_write_unlock(inode->i_sb);
+                reiserfs_write_unlock_once(inode->i_sb, lock_depth);
 
                 /* the item was found, so new blocks were not added to the file
                  ** there is no need to make sure the inode is updated with this
@@ -935,7 +932,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
                         if (blocks_needed == 1) {
                                 un = &unf_single;
                         } else {
-                                un = kzalloc(min(blocks_needed, max_to_insert) * UNFM_P_SIZE, GFP_ATOMIC);      // We need to avoid scheduling.
+                                un = kzalloc(min(blocks_needed, max_to_insert) * UNFM_P_SIZE, GFP_NOFS);
                                 if (!un) {
                                         un = &unf_single;
                                         blocks_needed = 1;
@@ -997,10 +994,16 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
                         if (retval)
                                 goto failure;
                 }
-                /* inserting indirect pointers for a hole can take a
-                 ** long time.  reschedule if needed
+                /*
+                 * inserting indirect pointers for a hole can take a
+                 * long time.  reschedule if needed and also release the write
+                 * lock for others.
                  */
-                cond_resched();
+                if (need_resched()) {
+                        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+                        schedule();
+                        lock_depth = reiserfs_write_lock_once(inode->i_sb);
+                }
 
                 retval = search_for_position_by_key(inode->i_sb, &key, &path);
                 if (retval == IO_ERROR) {
@@ -1035,7 +1038,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block,
                         retval = err;
         }
 
-        reiserfs_write_unlock(inode->i_sb);
+        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
         reiserfs_check_path(&path);
         return retval;
 }
@@ -2072,8 +2075,9 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps)
         int error;
         struct buffer_head *bh = NULL;
         int err2;
+        int lock_depth;
 
-        reiserfs_write_lock(inode->i_sb);
+        lock_depth = reiserfs_write_lock_once(inode->i_sb);
 
         if (inode->i_size > 0) {
                 error = grab_tail_page(inode, &page, &bh);
@@ -2142,14 +2146,17 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps)
                 page_cache_release(page);
         }
 
-        reiserfs_write_unlock(inode->i_sb);
+        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+
         return 0;
       out:
         if (page) {
                 unlock_page(page);
                 page_cache_release(page);
         }
-        reiserfs_write_unlock(inode->i_sb);
+
+        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+
         return error;
 }
 
@@ -2608,7 +2615,10 @@ int reiserfs_prepare_write(struct file *f, struct page *page,
         int ret;
         int old_ref = 0;
 
+        reiserfs_write_unlock(inode->i_sb);
         reiserfs_wait_on_write_block(inode->i_sb);
+        reiserfs_write_lock(inode->i_sb);
+
         fix_tail_page_for_writing(page);
         if (reiserfs_transaction_running(inode->i_sb)) {
                 struct reiserfs_transaction_handle *th;
@@ -2664,6 +2674,8 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping,
         int update_sd = 0;
         struct reiserfs_transaction_handle *th;
         unsigned start;
+        int lock_depth = 0;
+        bool locked = false;
 
         if ((unsigned long)fsdata & AOP_FLAG_CONT_EXPAND)
                 pos ++;
@@ -2690,9 +2702,11 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping,
          ** to do the i_size updates here.
          */
         pos += copied;
+
         if (pos > inode->i_size) {
                 struct reiserfs_transaction_handle myth;
-                reiserfs_write_lock(inode->i_sb);
+                lock_depth = reiserfs_write_lock_once(inode->i_sb);
+                locked = true;
                 /* If the file have grown beyond the border where it
                    can have a tail, unmark it as needing a tail
                    packing */
@@ -2703,10 +2717,9 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping,
                         REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
 
                 ret = journal_begin(&myth, inode->i_sb, 1);
-                if (ret) {
-                        reiserfs_write_unlock(inode->i_sb);
+                if (ret)
                         goto journal_error;
-                }
+
                 reiserfs_update_inode_transaction(inode);
                 inode->i_size = pos;
                 /*
@@ -2718,34 +2731,36 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping,
                 reiserfs_update_sd(&myth, inode);
                 update_sd = 1;
                 ret = journal_end(&myth, inode->i_sb, 1);
-                reiserfs_write_unlock(inode->i_sb);
                 if (ret)
                         goto journal_error;
         }
         if (th) {
-                reiserfs_write_lock(inode->i_sb);
+                if (!locked) {
+                        lock_depth = reiserfs_write_lock_once(inode->i_sb);
+                        locked = true;
+                }
                 if (!update_sd)
                         mark_inode_dirty(inode);
                 ret = reiserfs_end_persistent_transaction(th);
-                reiserfs_write_unlock(inode->i_sb);
                 if (ret)
                         goto out;
         }
 
       out:
+        if (locked)
+                reiserfs_write_unlock_once(inode->i_sb, lock_depth);
         unlock_page(page);
         page_cache_release(page);
         return ret == 0 ? copied : ret;
 
       journal_error:
+        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
+        locked = false;
         if (th) {
-                reiserfs_write_lock(inode->i_sb);
                 if (!update_sd)
                         reiserfs_update_sd(th, inode);
                 ret = reiserfs_end_persistent_transaction(th);
-                reiserfs_write_unlock(inode->i_sb);
         }
-
         goto out;
 }
 
@@ -2758,7 +2773,10 @@ int reiserfs_commit_write(struct file *f, struct page *page,
         int update_sd = 0;
         struct reiserfs_transaction_handle *th = NULL;
 
+        reiserfs_write_unlock(inode->i_sb);
         reiserfs_wait_on_write_block(inode->i_sb);
+        reiserfs_write_lock(inode->i_sb);
+
         if (reiserfs_transaction_running(inode->i_sb)) {
                 th = current->journal_info;
         }
@@ -2770,7 +2788,6 @@ int reiserfs_commit_write(struct file *f, struct page *page,
          */
         if (pos > inode->i_size) {
                 struct reiserfs_transaction_handle myth;
-                reiserfs_write_lock(inode->i_sb);
                 /* If the file have grown beyond the border where it
                    can have a tail, unmark it as needing a tail
                    packing */
@@ -2781,10 +2798,9 @@ int reiserfs_commit_write(struct file *f, struct page *page,
                         REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
 
                 ret = journal_begin(&myth, inode->i_sb, 1);
-                if (ret) {
-                        reiserfs_write_unlock(inode->i_sb);
+                if (ret)
                         goto journal_error;
-                }
+
                 reiserfs_update_inode_transaction(inode);
                 inode->i_size = pos;
                 /*
@@ -2796,16 +2812,13 @@ int reiserfs_commit_write(struct file *f, struct page *page,
                 reiserfs_update_sd(&myth, inode);
                 update_sd = 1;
                 ret = journal_end(&myth, inode->i_sb, 1);
-                reiserfs_write_unlock(inode->i_sb);
                 if (ret)
                         goto journal_error;
         }
         if (th) {
-                reiserfs_write_lock(inode->i_sb);
                 if (!update_sd)
                         mark_inode_dirty(inode);
                 ret = reiserfs_end_persistent_transaction(th);
-                reiserfs_write_unlock(inode->i_sb);
                 if (ret)
                         goto out;
         }
@@ -2815,11 +2828,9 @@ int reiserfs_commit_write(struct file *f, struct page *page,
 
       journal_error:
         if (th) {
-                reiserfs_write_lock(inode->i_sb);
                 if (!update_sd)
                         reiserfs_update_sd(th, inode);
                 ret = reiserfs_end_persistent_transaction(th);
-                reiserfs_write_unlock(inode->i_sb);
         }
 
         return ret;
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index 0ccc3fdda7bf..ace77451ceb1 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -13,44 +13,52 @@
 #include <linux/compat.h>
 
 /*
-** reiserfs_ioctl - handler for ioctl for inode
-** supported commands:
-**  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
-**                           and prevent packing file (argument arg has to be non-zero)
-**  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
-**  3) That's all for a while ...
-*/
-int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
-                   unsigned long arg)
+ * reiserfs_ioctl - handler for ioctl for inode
+ * supported commands:
+ *  1) REISERFS_IOC_UNPACK - try to unpack tail from direct item into indirect
+ *                           and prevent packing file (argument arg has to be non-zero)
+ *  2) REISERFS_IOC_[GS]ETFLAGS, REISERFS_IOC_[GS]ETVERSION
+ *  3) That's all for a while ...
+ */
+long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+        struct inode *inode = filp->f_path.dentry->d_inode;
         unsigned int flags;
         int err = 0;
 
+        reiserfs_write_lock(inode->i_sb);
+
         switch (cmd) {
         case REISERFS_IOC_UNPACK:
                 if (S_ISREG(inode->i_mode)) {
                         if (arg)
-                                return reiserfs_unpack(inode, filp);
-                        else
-                                return 0;
+                                err = reiserfs_unpack(inode, filp);
                 } else
-                        return -ENOTTY;
-                /* following two cases are taken from fs/ext2/ioctl.c by Remy
-                   Card (card@masi.ibp.fr) */
+                        err = -ENOTTY;
+                break;
+                /*
+                 * following two cases are taken from fs/ext2/ioctl.c by Remy
+                 * Card (card@masi.ibp.fr)
+                 */
         case REISERFS_IOC_GETFLAGS:
-                if (!reiserfs_attrs(inode->i_sb))
-                        return -ENOTTY;
+                if (!reiserfs_attrs(inode->i_sb)) {
+                        err = -ENOTTY;
+                        break;
+                }
 
                 flags = REISERFS_I(inode)->i_attrs;
                 i_attrs_to_sd_attrs(inode, (__u16 *) & flags);
-                return put_user(flags, (int __user *)arg);
+                err = put_user(flags, (int __user *)arg);
+                break;
         case REISERFS_IOC_SETFLAGS:{
-                        if (!reiserfs_attrs(inode->i_sb))
-                                return -ENOTTY;
+                        if (!reiserfs_attrs(inode->i_sb)) {
+                                err = -ENOTTY;
+                                break;
+                        }
 
                         err = mnt_want_write(filp->f_path.mnt);
                         if (err)
-                                return err;
+                                break;
 
                         if (!is_owner_or_cap(inode)) {
                                 err = -EPERM;
@@ -90,16 +98,18 @@ int reiserfs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
                         mark_inode_dirty(inode);
 setflags_out:
                         mnt_drop_write(filp->f_path.mnt);
-                        return err;
+                        break;
                 }
         case REISERFS_IOC_GETVERSION:
-                return put_user(inode->i_generation, (int __user *)arg);
+                err = put_user(inode->i_generation, (int __user *)arg);
+                break;
         case REISERFS_IOC_SETVERSION:
                 if (!is_owner_or_cap(inode))
-                        return -EPERM;
+                        err = -EPERM;
+                        break;
                 err = mnt_want_write(filp->f_path.mnt);
                 if (err)
-                        return err;
+                        break;
                 if (get_user(inode->i_generation, (int __user *)arg)) {
                         err = -EFAULT;
                         goto setversion_out;
@@ -108,19 +118,20 @@ setflags_out:
                 mark_inode_dirty(inode);
 setversion_out:
                 mnt_drop_write(filp->f_path.mnt);
-                return err;
+                break;
         default:
-                return -ENOTTY;
+                err = -ENOTTY;
         }
+
+        reiserfs_write_unlock(inode->i_sb);
+
+        return err;
 }
 
 #ifdef CONFIG_COMPAT
 long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
                                 unsigned long arg)
 {
-        struct inode *inode = file->f_path.dentry->d_inode;
-        int ret;
-
         /* These are just misnamed, they actually get/put from/to user an int */
         switch (cmd) {
         case REISERFS_IOC32_UNPACK:
@@ -141,10 +152,8 @@ long reiserfs_compat_ioctl(struct file *file, unsigned int cmd,
         default:
                 return -ENOIOCTLCMD;
         }
-        lock_kernel();
-        ret = reiserfs_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
-        unlock_kernel();
-        return ret;
+
+        return reiserfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif
 
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 90622200b39c..2f8a7e7b8dab 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -429,21 +429,6 @@ static void clear_prepared_bits(struct buffer_head *bh)
         clear_buffer_journal_restore_dirty(bh);
 }
 
-/* utility function to force a BUG if it is called without the big
-** kernel lock held.  caller is the string printed just before calling BUG()
-*/
-void reiserfs_check_lock_depth(struct super_block *sb, char *caller)
-{
-#ifdef CONFIG_SMP
-        if (current->lock_depth < 0) {
-                reiserfs_panic(sb, "journal-1", "%s called without kernel "
-                               "lock held", caller);
-        }
-#else
-        ;
-#endif
-}
-
 /* return a cnode with same dev, block number and size in table, or null if not found */
 static inline struct reiserfs_journal_cnode *get_journal_hash_dev(struct
                                                                   super_block
@@ -556,7 +541,8 @@ static inline void insert_journal_hash(struct reiserfs_journal_cnode **table,
 static inline void lock_journal(struct super_block *sb)
 {
         PROC_INFO_INC(sb, journal.lock_journal);
-        mutex_lock(&SB_JOURNAL(sb)->j_mutex);
+
+        reiserfs_mutex_lock_safe(&SB_JOURNAL(sb)->j_mutex, sb);
 }
 
 /* unlock the current transaction */
@@ -708,7 +694,9 @@ static void check_barrier_completion(struct super_block *s,
                 disable_barrier(s);
                 set_buffer_uptodate(bh);
                 set_buffer_dirty(bh);
+                reiserfs_write_unlock(s);
                 sync_dirty_buffer(bh);
+                reiserfs_write_lock(s);
         }
 }
 
@@ -996,8 +984,13 @@ static int reiserfs_async_progress_wait(struct super_block *s)
 {
         DEFINE_WAIT(wait);
         struct reiserfs_journal *j = SB_JOURNAL(s);
-        if (atomic_read(&j->j_async_throttle))
+
+        if (atomic_read(&j->j_async_throttle)) {
+                reiserfs_write_unlock(s);
                 congestion_wait(BLK_RW_ASYNC, HZ / 10);
+                reiserfs_write_lock(s);
+        }
+
         return 0;
 }
 
@@ -1043,7 +1036,8 @@ static int flush_commit_list(struct super_block *s,
         }
 
         /* make sure nobody is trying to flush this one at the same time */
-        mutex_lock(&jl->j_commit_mutex);
+        reiserfs_mutex_lock_safe(&jl->j_commit_mutex, s);
+
         if (!journal_list_still_alive(s, trans_id)) {
                 mutex_unlock(&jl->j_commit_mutex);
                 goto put_jl;
@@ -1061,12 +1055,17 @@ static int flush_commit_list(struct super_block *s,
 
         if (!list_empty(&jl->j_bh_list)) {
                 int ret;
-                unlock_kernel();
+
+                /*
+                 * We might sleep in numerous places inside
+                 * write_ordered_buffers. Relax the write lock.
+                 */
+                reiserfs_write_unlock(s);
                 ret = write_ordered_buffers(&journal->j_dirty_buffers_lock,
                                             journal, jl, &jl->j_bh_list);
                 if (ret < 0 && retval == 0)
                         retval = ret;
-                lock_kernel();
+                reiserfs_write_lock(s);
         }
         BUG_ON(!list_empty(&jl->j_bh_list));
         /*
@@ -1085,8 +1084,11 @@ static int flush_commit_list(struct super_block *s,
                     SB_ONDISK_JOURNAL_SIZE(s);
                 tbh = journal_find_get_block(s, bn);
                 if (tbh) {
-                        if (buffer_dirty(tbh))
-                            ll_rw_block(WRITE, 1, &tbh) ;
+                        if (buffer_dirty(tbh)) {
+                            reiserfs_write_unlock(s);
+                            ll_rw_block(WRITE, 1, &tbh);
+                            reiserfs_write_lock(s);
+                        }
                         put_bh(tbh) ;
                 }
         }
@@ -1114,12 +1116,19 @@ static int flush_commit_list(struct super_block *s,
                 bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
                     (jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
                 tbh = journal_find_get_block(s, bn);
+
+                reiserfs_write_unlock(s);
                 wait_on_buffer(tbh);
+                reiserfs_write_lock(s);
                 // since we're using ll_rw_blk above, it might have skipped over
                 // a locked buffer.  Double check here
                 //
-                if (buffer_dirty(tbh))  /* redundant, sync_dirty_buffer() checks */
+                /* redundant, sync_dirty_buffer() checks */
+                if (buffer_dirty(tbh)) {
+                        reiserfs_write_unlock(s);
                         sync_dirty_buffer(tbh);
+                        reiserfs_write_lock(s);
+                }
                 if (unlikely(!buffer_uptodate(tbh))) {
 #ifdef CONFIG_REISERFS_CHECK
                         reiserfs_warning(s, "journal-601",
@@ -1143,10 +1152,15 @@ static int flush_commit_list(struct super_block *s,
                         if (buffer_dirty(jl->j_commit_bh))
                                 BUG();
                         mark_buffer_dirty(jl->j_commit_bh) ;
+                        reiserfs_write_unlock(s);
                         sync_dirty_buffer(jl->j_commit_bh) ;
+                        reiserfs_write_lock(s);
                 }
-        } else
+        } else {
+                reiserfs_write_unlock(s);
                 wait_on_buffer(jl->j_commit_bh);
+                reiserfs_write_lock(s);
+        }
 
         check_barrier_completion(s, jl->j_commit_bh);
 
@@ -1286,7 +1300,9 @@ static int _update_journal_header_block(struct super_block *sb,
 
         if (trans_id >= journal->j_last_flush_trans_id) {
                 if (buffer_locked((journal->j_header_bh))) {
+                        reiserfs_write_unlock(sb);
                         wait_on_buffer((journal->j_header_bh));
+                        reiserfs_write_lock(sb);
                         if (unlikely(!buffer_uptodate(journal->j_header_bh))) {
 #ifdef CONFIG_REISERFS_CHECK
                                 reiserfs_warning(sb, "journal-699",
@@ -1312,12 +1328,16 @@ static int _update_journal_header_block(struct super_block *sb,
                                 disable_barrier(sb);
                                 goto sync;
                         }
+                        reiserfs_write_unlock(sb);
                         wait_on_buffer(journal->j_header_bh);
+                        reiserfs_write_lock(sb);
                         check_barrier_completion(sb, journal->j_header_bh);
                 } else {
                       sync:
                         set_buffer_dirty(journal->j_header_bh);
+                        reiserfs_write_unlock(sb);
                         sync_dirty_buffer(journal->j_header_bh);
+                        reiserfs_write_lock(sb);
                 }
                 if (!buffer_uptodate(journal->j_header_bh)) {
                         reiserfs_warning(sb, "journal-837",
@@ -1409,7 +1429,7 @@ static int flush_journal_list(struct super_block *s,
 
         /* if flushall == 0, the lock is already held */
         if (flushall) {
-                mutex_lock(&journal->j_flush_mutex);
+                reiserfs_mutex_lock_safe(&journal->j_flush_mutex, s);
         } else if (mutex_trylock(&journal->j_flush_mutex)) {
                 BUG();
         }
@@ -1553,7 +1573,11 @@ static int flush_journal_list(struct super_block *s,
                                         reiserfs_panic(s, "journal-1011",
                                                        "cn->bh is NULL");
                                 }
+
+                                reiserfs_write_unlock(s);
                                 wait_on_buffer(cn->bh);
+                                reiserfs_write_lock(s);
+
                                 if (!cn->bh) {
                                         reiserfs_panic(s, "journal-1012",
                                                        "cn->bh is NULL");
@@ -1769,7 +1793,7 @@ static int kupdate_transactions(struct super_block *s,
         struct reiserfs_journal *journal = SB_JOURNAL(s);
         chunk.nr = 0;
 
-        mutex_lock(&journal->j_flush_mutex);
+        reiserfs_mutex_lock_safe(&journal->j_flush_mutex, s);
         if (!journal_list_still_alive(s, orig_trans_id)) {
                 goto done;
         }
@@ -1973,11 +1997,19 @@ static int do_journal_release(struct reiserfs_transaction_handle *th,
         reiserfs_mounted_fs_count--;
         /* wait for all commits to finish */
         cancel_delayed_work(&SB_JOURNAL(sb)->j_work);
+
+        /*
+         * We must release the write lock here because
+         * the workqueue job (flush_async_commit) needs this lock
+         */
+        reiserfs_write_unlock(sb);
         flush_workqueue(commit_wq);
+
         if (!reiserfs_mounted_fs_count) {
                 destroy_workqueue(commit_wq);
                 commit_wq = NULL;
         }
+        reiserfs_write_lock(sb);
 
         free_journal_ram(sb);
 
@@ -2243,7 +2275,11 @@ static int journal_read_transaction(struct super_block *sb,
         /* read in the log blocks, memcpy to the corresponding real block */
         ll_rw_block(READ, get_desc_trans_len(desc), log_blocks);
         for (i = 0; i < get_desc_trans_len(desc); i++) {
+
+                reiserfs_write_unlock(sb);
                 wait_on_buffer(log_blocks[i]);
+                reiserfs_write_lock(sb);
+
                 if (!buffer_uptodate(log_blocks[i])) {
                         reiserfs_warning(sb, "journal-1212",
                                          "REPLAY FAILURE fsck required! "
@@ -2765,11 +2801,27 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
                 goto free_and_return;
         }
 
+        /*
+         * We need to unlock here to avoid creating the following
+         * dependency:
+         * reiserfs_lock -> sysfs_mutex
+         * Because the reiserfs mmap path creates the following dependency:
+         * mm->mmap -> reiserfs_lock, hence we have
+         * mm->mmap -> reiserfs_lock ->sysfs_mutex
+         * This would ends up in a circular dependency with sysfs readdir path
+         * which does sysfs_mutex -> mm->mmap_sem
+         * This is fine because the reiserfs lock is useless in mount path,
+         * at least until we call journal_begin. We keep it for paranoid
+         * reasons.
+         */
+        reiserfs_write_unlock(sb);
         if (journal_init_dev(sb, journal, j_dev_name) != 0) {
+                reiserfs_write_lock(sb);
                 reiserfs_warning(sb, "sh-462",
                                  "unable to initialize jornal device");
                 goto free_and_return;
         }
+        reiserfs_write_lock(sb);
 
         rs = SB_DISK_SUPER_BLOCK(sb);
 
@@ -2881,8 +2933,11 @@ int journal_init(struct super_block *sb, const char *j_dev_name,
         }
 
         reiserfs_mounted_fs_count++;
-        if (reiserfs_mounted_fs_count <= 1)
+        if (reiserfs_mounted_fs_count <= 1) {
+                reiserfs_write_unlock(sb);
                 commit_wq = create_workqueue("reiserfs");
+                reiserfs_write_lock(sb);
+        }
 
         INIT_DELAYED_WORK(&journal->j_work, flush_async_commits);
         journal->j_work_sb = sb;
@@ -2964,8 +3019,11 @@ static void queue_log_writer(struct super_block *s)
         init_waitqueue_entry(&wait, current);
         add_wait_queue(&journal->j_join_wait, &wait);
         set_current_state(TASK_UNINTERRUPTIBLE);
-        if (test_bit(J_WRITERS_QUEUED, &journal->j_state))
+        if (test_bit(J_WRITERS_QUEUED, &journal->j_state)) {
+                reiserfs_write_unlock(s);
                 schedule();
+                reiserfs_write_lock(s);
+        }
         __set_current_state(TASK_RUNNING);
         remove_wait_queue(&journal->j_join_wait, &wait);
 }
@@ -2982,7 +3040,9 @@ static void let_transaction_grow(struct super_block *sb, unsigned int trans_id)
         struct reiserfs_journal *journal = SB_JOURNAL(sb);
         unsigned long bcount = journal->j_bcount;
         while (1) {
+                reiserfs_write_unlock(sb);
                 schedule_timeout_uninterruptible(1);
+                reiserfs_write_lock(sb);
                 journal->j_current_jl->j_state |= LIST_COMMIT_PENDING;
                 while ((atomic_read(&journal->j_wcount) > 0 ||
                         atomic_read(&journal->j_jlock)) &&
@@ -3033,7 +3093,9 @@ static int do_journal_begin_r(struct reiserfs_transaction_handle *th,
 
         if (test_bit(J_WRITERS_BLOCKED, &journal->j_state)) {
                 unlock_journal(sb);
+                reiserfs_write_unlock(sb);
                 reiserfs_wait_on_write_block(sb);
+                reiserfs_write_lock(sb);
                 PROC_INFO_INC(sb, journal.journal_relock_writers);
                 goto relock;
         }
@@ -3506,14 +3568,14 @@ static void flush_async_commits(struct work_struct *work)
         struct reiserfs_journal_list *jl;
         struct list_head *entry;
 
-        lock_kernel();
+        reiserfs_write_lock(sb);
         if (!list_empty(&journal->j_journal_list)) {
                 /* last entry is the youngest, commit it and you get everything */
                 entry = journal->j_journal_list.prev;
                 jl = JOURNAL_LIST_ENTRY(entry);
                 flush_commit_list(sb, jl, 1);
         }
-        unlock_kernel();
+        reiserfs_write_unlock(sb);
 }
 
 /*
@@ -4041,7 +4103,7 @@ static int do_journal_end(struct reiserfs_transaction_handle *th,
          * the new transaction is fully setup, and we've already flushed the
          * ordered bh list
          */
-        mutex_lock(&jl->j_commit_mutex);
+        reiserfs_mutex_lock_safe(&jl->j_commit_mutex, sb);
 
         /* save the transaction id in case we need to commit it later */
         commit_trans_id = jl->j_trans_id;
@@ -4156,7 +4218,9 @@ static int do_journal_end(struct reiserfs_transaction_handle *th,
                 next = cn->next;
                 free_cnode(sb, cn);
                 cn = next;
+                reiserfs_write_unlock(sb);
                 cond_resched();
+                reiserfs_write_lock(sb);
         }
 
         /* we are done  with both the c_bh and d_bh, but
@@ -4203,10 +4267,10 @@ static int do_journal_end(struct reiserfs_transaction_handle *th,
          * is lost.
          */
         if (!list_empty(&jl->j_tail_bh_list)) {
-                unlock_kernel();
+                reiserfs_write_unlock(sb);
                 write_ordered_buffers(&journal->j_dirty_buffers_lock,
                                       journal, jl, &jl->j_tail_bh_list);
-                lock_kernel();
+                reiserfs_write_lock(sb);
         }
         BUG_ON(!list_empty(&jl->j_tail_bh_list));
         mutex_unlock(&jl->j_commit_mutex);
diff --git a/fs/reiserfs/lock.c b/fs/reiserfs/lock.c
new file mode 100644
index 000000000000..ee2cfc0fd8a7
--- /dev/null
+++ b/fs/reiserfs/lock.c
@@ -0,0 +1,88 @@
+#include <linux/reiserfs_fs.h>
+#include <linux/mutex.h>
+
+/*
+ * The previous reiserfs locking scheme was heavily based on
+ * the tricky properties of the Bkl:
+ *
+ * - it was acquired recursively by a same task
+ * - the performances relied on the release-while-schedule() property
+ *
+ * Now that we replace it by a mutex, we still want to keep the same
+ * recursive property to avoid big changes in the code structure.
+ * We use our own lock_owner here because the owner field on a mutex
+ * is only available in SMP or mutex debugging, also we only need this field
+ * for this mutex, no need for a system wide mutex facility.
+ *
+ * Also this lock is often released before a call that could block because
+ * reiserfs performances were partialy based on the release while schedule()
+ * property of the Bkl.
+ */
+void reiserfs_write_lock(struct super_block *s)
+{
+        struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+
+        if (sb_i->lock_owner != current) {
+                mutex_lock(&sb_i->lock);
+                sb_i->lock_owner = current;
+        }
+
+        /* No need to protect it, only the current task touches it */
+        sb_i->lock_depth++;
+}
+
+void reiserfs_write_unlock(struct super_block *s)
+{
+        struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+
+        /*
+         * Are we unlocking without even holding the lock?
+         * Such a situation must raise a BUG() if we don't want
+         * to corrupt the data.
+         */
+        BUG_ON(sb_i->lock_owner != current);
+
+        if (--sb_i->lock_depth == -1) {
+                sb_i->lock_owner = NULL;
+                mutex_unlock(&sb_i->lock);
+        }
+}
+
+/*
+ * If we already own the lock, just exit and don't increase the depth.
+ * Useful when we don't want to lock more than once.
+ *
+ * We always return the lock_depth we had before calling
+ * this function.
+ */
+int reiserfs_write_lock_once(struct super_block *s)
+{
+        struct reiserfs_sb_info *sb_i = REISERFS_SB(s);
+
+        if (sb_i->lock_owner != current) {
+                mutex_lock(&sb_i->lock);
+                sb_i->lock_owner = current;
+                return sb_i->lock_depth++;
+        }
+
+        return sb_i->lock_depth;
+}
+
+void reiserfs_write_unlock_once(struct super_block *s, int lock_depth)
+{
+        if (lock_depth == -1)
+                reiserfs_write_unlock(s);
+}
+
+/*
+ * Utility function to force a BUG if it is called without the superblock
+ * write lock held.  caller is the string printed just before calling BUG()
+ */
+void reiserfs_check_lock_depth(struct super_block *sb, char *caller)
+{
+        struct reiserfs_sb_info *sb_i = REISERFS_SB(sb);
+
+        if (sb_i->lock_depth < 0)
+                reiserfs_panic(sb, "%s called without kernel lock held %d",
+                               caller);
+}
diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c
index 271579128634..e296ff72a6cc 100644
--- a/fs/reiserfs/namei.c
+++ b/fs/reiserfs/namei.c
@@ -324,6 +324,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
                                       struct nameidata *nd)
 {
         int retval;
+        int lock_depth;
         struct inode *inode = NULL;
         struct reiserfs_dir_entry de;
         INITIALIZE_PATH(path_to_entry);
@@ -331,7 +332,13 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
         if (REISERFS_MAX_NAME(dir->i_sb->s_blocksize) < dentry->d_name.len)
                 return ERR_PTR(-ENAMETOOLONG);
 
-        reiserfs_write_lock(dir->i_sb);
+        /*
+         * Might be called with or without the write lock, must be careful
+         * to not recursively hold it in case we want to release the lock
+         * before rescheduling.
+         */
+        lock_depth = reiserfs_write_lock_once(dir->i_sb);
+
         de.de_gen_number_bit_string = NULL;
         retval =
             reiserfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len,
@@ -341,7 +348,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
                 inode = reiserfs_iget(dir->i_sb,
                                       (struct cpu_key *)&(de.de_dir_id));
                 if (!inode || IS_ERR(inode)) {
-                        reiserfs_write_unlock(dir->i_sb);
+                        reiserfs_write_unlock_once(dir->i_sb, lock_depth);
                         return ERR_PTR(-EACCES);
                 }
 
@@ -350,7 +357,7 @@ static struct dentry *reiserfs_lookup(struct inode *dir, struct dentry *dentry,
                 if (IS_PRIVATE(dir))
                         inode->i_flags |= S_PRIVATE;
         }
-        reiserfs_write_unlock(dir->i_sb);
+        reiserfs_write_unlock_once(dir->i_sb, lock_depth);
         if (retval == IO_ERROR) {
                 return ERR_PTR(-EIO);
         }
@@ -725,6 +732,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         struct inode *inode;
         struct reiserfs_transaction_handle th;
         struct reiserfs_security_handle security;
+        int lock_depth;
         /* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */
         int jbegin_count =
             JOURNAL_PER_BALANCE_CNT * 3 +
@@ -748,7 +756,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
                 return retval;
         }
         jbegin_count += retval;
-        reiserfs_write_lock(dir->i_sb);
+        lock_depth = reiserfs_write_lock_once(dir->i_sb);
 
         retval = journal_begin(&th, dir->i_sb, jbegin_count);
         if (retval) {
@@ -798,8 +806,8 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
         d_instantiate(dentry, inode);
         unlock_new_inode(inode);
         retval = journal_end(&th, dir->i_sb, jbegin_count);
-      out_failed:
-        reiserfs_write_unlock(dir->i_sb);
+out_failed:
+        reiserfs_write_unlock_once(dir->i_sb, lock_depth);
         return retval;
 }
 
diff --git a/fs/reiserfs/prints.c b/fs/reiserfs/prints.c
index 536eacaeb710..adbc6f538515 100644
--- a/fs/reiserfs/prints.c
+++ b/fs/reiserfs/prints.c
@@ -349,10 +349,6 @@ void reiserfs_debug(struct super_block *s, int level, const char *fmt, ...)
 
    .  */
 
-#ifdef CONFIG_REISERFS_CHECK
-extern struct tree_balance *cur_tb;
-#endif
-
 void __reiserfs_panic(struct super_block *sb, const char *id,
                       const char *function, const char *fmt, ...)
 {
diff --git a/fs/reiserfs/resize.c b/fs/reiserfs/resize.c
index 18b315d3d104..b3a94d20f0fc 100644
--- a/fs/reiserfs/resize.c
+++ b/fs/reiserfs/resize.c
@@ -141,7 +141,9 @@ int reiserfs_resize(struct super_block *s, unsigned long block_count_new)
 
                         set_buffer_uptodate(bh);
                         mark_buffer_dirty(bh);
+                        reiserfs_write_unlock(s);
                         sync_dirty_buffer(bh);
+                        reiserfs_write_lock(s);
                         // update bitmap_info stuff
                         bitmap[i].free_count = sb_blocksize(sb) * 8 - 1;
                         brelse(bh);
diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
index d036ee5b1c81..5fa7118f04e1 100644
--- a/fs/reiserfs/stree.c
+++ b/fs/reiserfs/stree.c
@@ -222,9 +222,6 @@ static inline int bin_search(const void *key,	/* Key to search for. */
         return ITEM_NOT_FOUND;
 }
 
-#ifdef CONFIG_REISERFS_CHECK
-extern struct tree_balance *cur_tb;
-#endif
 
 /* Minimal possible key. It is never in the tree. */
 const struct reiserfs_key MIN_KEY = { 0, 0, {{0, 0},} };
@@ -519,25 +516,48 @@ static int is_tree_node(struct buffer_head *bh, int level)
 
 #define SEARCH_BY_KEY_READA 16
 
-/* The function is NOT SCHEDULE-SAFE! */
-static void search_by_key_reada(struct super_block *s,
+/*
+ * The function is NOT SCHEDULE-SAFE!
+ * It might unlock the write lock if we needed to wait for a block
+ * to be read. Note that in this case it won't recover the lock to avoid
+ * high contention resulting from too much lock requests, especially
+ * the caller (search_by_key) will perform other schedule-unsafe
+ * operations just after calling this function.
+ *
+ * @return true if we have unlocked
+ */
+static bool search_by_key_reada(struct super_block *s,
                                 struct buffer_head **bh,
                                 b_blocknr_t *b, int num)
 {
         int i, j;
+        bool unlocked = false;
 
         for (i = 0; i < num; i++) {
                 bh[i] = sb_getblk(s, b[i]);
         }
+        /*
+         * We are going to read some blocks on which we
+         * have a reference. It's safe, though we might be
+         * reading blocks concurrently changed if we release
+         * the lock. But it's still fine because we check later
+         * if the tree changed
+         */
         for (j = 0; j < i; j++) {
                 /*
                  * note, this needs attention if we are getting rid of the BKL
                  * you have to make sure the prepared bit isn't set on this buffer
                  */
-                if (!buffer_uptodate(bh[j]))
+                if (!buffer_uptodate(bh[j])) {
+                        if (!unlocked) {
+                                reiserfs_write_unlock(s);
+                                unlocked = true;
+                        }
                         ll_rw_block(READA, 1, bh + j);
+                }
                 brelse(bh[j]);
         }
+        return unlocked;
 }
 
 /**************************************************************************
@@ -625,11 +645,26 @@ int search_by_key(struct super_block *sb, const struct cpu_key *key,	/* Key to s
                    have a pointer to it. */
                 if ((bh = last_element->pe_buffer =
                      sb_getblk(sb, block_number))) {
+                        bool unlocked = false;
+
                         if (!buffer_uptodate(bh) && reada_count > 1)
-                                search_by_key_reada(sb, reada_bh,
+                                /* may unlock the write lock */
+                                unlocked = search_by_key_reada(sb, reada_bh,
                                                     reada_blocks, reada_count);
+                        /*
+                         * If we haven't already unlocked the write lock,
+                         * then we need to do that here before reading
+                         * the current block
+                         */
+                        if (!buffer_uptodate(bh) && !unlocked) {
+                                reiserfs_write_unlock(sb);
+                                unlocked = true;
+                        }
                         ll_rw_block(READ, 1, &bh);
                         wait_on_buffer(bh);
+
+                        if (unlocked)
+                                reiserfs_write_lock(sb);
                         if (!buffer_uptodate(bh))
                                 goto io_error;
                 } else {
@@ -673,7 +708,7 @@ int search_by_key(struct super_block *sb, const struct cpu_key *key,	/* Key to s
                        !key_in_buffer(search_path, key, sb),
                        "PAP-5130: key is not in the buffer");
 #ifdef CONFIG_REISERFS_CHECK
-                if (cur_tb) {
+                if (REISERFS_SB(sb)->cur_tb) {
                         print_cur_tb("5140");
                         reiserfs_panic(sb, "PAP-5140",
                                        "schedule occurred in do_balance!");
@@ -1024,7 +1059,9 @@ static char prepare_for_delete_or_cut(struct reiserfs_transaction_handle *th, st
                         reiserfs_free_block(th, inode, block, 1);
                     }
 
+                    reiserfs_write_unlock(sb);
                     cond_resched();
+                    reiserfs_write_lock(sb);
 
                     if (item_moved (&s_ih, path))  {
                         need_re_search = 1;
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index f0ad05f38022..339b0baf2af6 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -465,7 +465,7 @@ static void reiserfs_put_super(struct super_block *s)
         struct reiserfs_transaction_handle th;
         th.t_trans_id = 0;
 
-        lock_kernel();
+        reiserfs_write_lock(s);
 
         if (s->s_dirt)
                 reiserfs_write_super(s);
@@ -499,10 +499,10 @@ static void reiserfs_put_super(struct super_block *s)
 
         reiserfs_proc_info_done(s);
 
+        reiserfs_write_unlock(s);
+        mutex_destroy(&REISERFS_SB(s)->lock);
         kfree(s->s_fs_info);
         s->s_fs_info = NULL;
-
-        unlock_kernel();
 }
 
 static struct kmem_cache *reiserfs_inode_cachep;
@@ -554,25 +554,28 @@ static void reiserfs_dirty_inode(struct inode *inode)
         struct reiserfs_transaction_handle th;
 
         int err = 0;
+        int lock_depth;
+
         if (inode->i_sb->s_flags & MS_RDONLY) {
                 reiserfs_warning(inode->i_sb, "clm-6006",
                                  "writing inode %lu on readonly FS",
                                  inode->i_ino);
                 return;
         }
-        reiserfs_write_lock(inode->i_sb);
+        lock_depth = reiserfs_write_lock_once(inode->i_sb);
 
         /* this is really only used for atime updates, so they don't have
          ** to be included in O_SYNC or fsync
          */
         err = journal_begin(&th, inode->i_sb, 1);
-        if (err) {
-                reiserfs_write_unlock(inode->i_sb);
-                return;
-        }
+        if (err)
+                goto out;
+
         reiserfs_update_sd(&th, inode);
         journal_end(&th, inode->i_sb, 1);
-        reiserfs_write_unlock(inode->i_sb);
+
+out:
+        reiserfs_write_unlock_once(inode->i_sb, lock_depth);
 }
 
 #ifdef CONFIG_QUOTA
@@ -1168,11 +1171,14 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
         unsigned int qfmt = 0;
 #ifdef CONFIG_QUOTA
         int i;
+#endif
+
+        reiserfs_write_lock(s);
 
+#ifdef CONFIG_QUOTA
         memcpy(qf_names, REISERFS_SB(s)->s_qf_names, sizeof(qf_names));
 #endif
 
-        lock_kernel();
         rs = SB_DISK_SUPER_BLOCK(s);
 
         if (!reiserfs_parse_options
@@ -1295,12 +1301,12 @@ static int reiserfs_remount(struct super_block *s, int *mount_flags, char *arg)
 
 out_ok:
         replace_mount_options(s, new_opts);
-        unlock_kernel();
+        reiserfs_write_unlock(s);
         return 0;
 
 out_err:
         kfree(new_opts);
-        unlock_kernel();
+        reiserfs_write_unlock(s);
         return err;
 }
 
@@ -1404,7 +1410,9 @@ static int read_super_block(struct super_block *s, int offset)
 static int reread_meta_blocks(struct super_block *s)
 {
         ll_rw_block(READ, 1, &(SB_BUFFER_WITH_SB(s)));
+        reiserfs_write_unlock(s);
         wait_on_buffer(SB_BUFFER_WITH_SB(s));
+        reiserfs_write_lock(s);
         if (!buffer_uptodate(SB_BUFFER_WITH_SB(s))) {
                 reiserfs_warning(s, "reiserfs-2504", "error reading the super");
                 return 1;
@@ -1613,7 +1621,7 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
         sbi = kzalloc(sizeof(struct reiserfs_sb_info), GFP_KERNEL);
         if (!sbi) {
                 errval = -ENOMEM;
-                goto error;
+                goto error_alloc;
         }
         s->s_fs_info = sbi;
         /* Set default values for options: non-aggressive tails, RO on errors */
@@ -1627,6 +1635,20 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
         /* setup default block allocator options */
         reiserfs_init_alloc_options(s);
 
+        mutex_init(&REISERFS_SB(s)->lock);
+        REISERFS_SB(s)->lock_depth = -1;
+
+        /*
+         * This function is called with the bkl, which also was the old
+         * locking used here.
+         * do_journal_begin() will soon check if we hold the lock (ie: was the
+         * bkl). This is likely because do_journal_begin() has several another
+         * callers because at this time, it doesn't seem to be necessary to
+         * protect against anything.
+         * Anyway, let's be conservative and lock for now.
+         */
+        reiserfs_write_lock(s);
+
         jdev_name = NULL;
         if (reiserfs_parse_options
             (s, (char *)data, &(sbi->s_mount_opt), &blocks, &jdev_name,
@@ -1852,9 +1874,13 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
         init_waitqueue_head(&(sbi->s_wait));
         spin_lock_init(&sbi->bitmap_lock);
 
+        reiserfs_write_unlock(s);
+
         return (0);
 
 error:
+        reiserfs_write_unlock(s);
+error_alloc:
         if (jinit_done) {       /* kill the commit thread, free journal ram */
                 journal_release_error(NULL, s);
         }
diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c
index 6925b835a43b..58aa8e75f7f5 100644
--- a/fs/reiserfs/xattr.c
+++ b/fs/reiserfs/xattr.c
@@ -975,7 +975,7 @@ int reiserfs_lookup_privroot(struct super_block *s)
         int err = 0;
 
         /* If we don't have the privroot located yet - go find it */
-        mutex_lock(&s->s_root->d_inode->i_mutex);
+        reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
         dentry = lookup_one_len(PRIVROOT_NAME, s->s_root,
                                 strlen(PRIVROOT_NAME));
         if (!IS_ERR(dentry)) {
@@ -1004,14 +1004,14 @@ int reiserfs_xattr_init(struct super_block *s, int mount_flags)
                 goto error;
 
         if (!privroot->d_inode && !(mount_flags & MS_RDONLY)) {
-                mutex_lock(&s->s_root->d_inode->i_mutex);
+                reiserfs_mutex_lock_safe(&s->s_root->d_inode->i_mutex, s);
                 err = create_privroot(REISERFS_SB(s)->priv_root);
                 mutex_unlock(&s->s_root->d_inode->i_mutex);
         }
 
         if (privroot->d_inode) {
                 s->s_xattr = reiserfs_xattr_handlers;
-                mutex_lock(&privroot->d_inode->i_mutex);
+                reiserfs_mutex_lock_safe(&privroot->d_inode->i_mutex, s);
                 if (!REISERFS_SB(s)->xattr_root) {
                         struct dentry *dentry;
                         dentry = lookup_one_len(XAROOT_NAME, privroot,