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-rw-r--r--Documentation/filesystems/directory-locking5
-rw-r--r--Documentation/filesystems/porting8
2 files changed, 7 insertions, 6 deletions
diff --git a/Documentation/filesystems/directory-locking b/Documentation/filesystems/directory-locking
index d7099a9266fb..ff7b611abf33 100644
--- a/Documentation/filesystems/directory-locking
+++ b/Documentation/filesystems/directory-locking
@@ -1,5 +1,6 @@
1 Locking scheme used for directory operations is based on two 1 Locking scheme used for directory operations is based on two
2kinds of locks - per-inode (->i_sem) and per-filesystem (->s_vfs_rename_sem). 2kinds of locks - per-inode (->i_mutex) and per-filesystem
3(->s_vfs_rename_mutex).
3 4
4 For our purposes all operations fall in 5 classes: 5 For our purposes all operations fall in 5 classes:
5 6
@@ -63,7 +64,7 @@ objects - A < B iff A is an ancestor of B.
63attempt to acquire some lock and already holds at least one lock. Let's 64attempt to acquire some lock and already holds at least one lock. Let's
64consider the set of contended locks. First of all, filesystem lock is 65consider the set of contended locks. First of all, filesystem lock is
65not contended, since any process blocked on it is not holding any locks. 66not contended, since any process blocked on it is not holding any locks.
66Thus all processes are blocked on ->i_sem. 67Thus all processes are blocked on ->i_mutex.
67 68
68 Non-directory objects are not contended due to (3). Thus link 69 Non-directory objects are not contended due to (3). Thus link
69creation can't be a part of deadlock - it can't be blocked on source 70creation can't be a part of deadlock - it can't be blocked on source
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 5531694059ab..dac45c92d872 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -107,7 +107,7 @@ free to drop it...
107--- 107---
108[informational] 108[informational]
109 109
110->link() callers hold ->i_sem on the object we are linking to. Some of your 110->link() callers hold ->i_mutex on the object we are linking to. Some of your
111problems might be over... 111problems might be over...
112 112
113--- 113---
@@ -130,9 +130,9 @@ went in - and hadn't been documented ;-/). Just remove it from fs_flags
130--- 130---
131[mandatory] 131[mandatory]
132 132
133->setattr() is called without BKL now. Caller _always_ holds ->i_sem, so 133->setattr() is called without BKL now. Caller _always_ holds ->i_mutex, so
134watch for ->i_sem-grabbing code that might be used by your ->setattr(). 134watch for ->i_mutex-grabbing code that might be used by your ->setattr().
135Callers of notify_change() need ->i_sem now. 135Callers of notify_change() need ->i_mutex now.
136 136
137--- 137---
138[recommended] 138[recommended]