diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/filesystems/directory-locking | 5 | ||||
-rw-r--r-- | Documentation/filesystems/porting | 8 |
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 |
2 | kinds of locks - per-inode (->i_sem) and per-filesystem (->s_vfs_rename_sem). | 2 | kinds 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. | |||
63 | attempt to acquire some lock and already holds at least one lock. Let's | 64 | attempt to acquire some lock and already holds at least one lock. Let's |
64 | consider the set of contended locks. First of all, filesystem lock is | 65 | consider the set of contended locks. First of all, filesystem lock is |
65 | not contended, since any process blocked on it is not holding any locks. | 66 | not contended, since any process blocked on it is not holding any locks. |
66 | Thus all processes are blocked on ->i_sem. | 67 | Thus 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 |
69 | creation can't be a part of deadlock - it can't be blocked on source | 70 | creation 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 |
111 | problems might be over... | 111 | problems 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 |
134 | watch for ->i_sem-grabbing code that might be used by your ->setattr(). | 134 | watch for ->i_mutex-grabbing code that might be used by your ->setattr(). |
135 | Callers of notify_change() need ->i_sem now. | 135 | Callers of notify_change() need ->i_mutex now. |
136 | 136 | ||
137 | --- | 137 | --- |
138 | [recommended] | 138 | [recommended] |