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| author | Michal Marek <mmarek@suse.cz> | 2010-10-28 00:15:57 +0200 |
|---|---|---|
| committer | Michal Marek <mmarek@suse.cz> | 2010-10-28 00:15:57 +0200 |
| commit | b74b953b998bcc2db91b694446f3a2619ec32de6 (patch) | |
| tree | 6ce24caabd730f6ae9287ed0676ec32e6ff31e9d /Documentation/filesystems/sharedsubtree.txt | |
| parent | abb438526201c6a79949ad45375c051b6681c253 (diff) | |
| parent | f6f94e2ab1b33f0082ac22d71f66385a60d8157f (diff) | |
| download | linux-stable-b74b953b998bcc2db91b694446f3a2619ec32de6.tar.gz linux-stable-b74b953b998bcc2db91b694446f3a2619ec32de6.tar.bz2 linux-stable-b74b953b998bcc2db91b694446f3a2619ec32de6.zip | |
Merge commit 'v2.6.36' into kbuild/misc
Update to be able to fix a recent change to scripts/basic/docproc.c
(commit eda603f).
Diffstat (limited to 'Documentation/filesystems/sharedsubtree.txt')
| -rw-r--r-- | Documentation/filesystems/sharedsubtree.txt | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt index 23a181074f94..fc0e39af43c3 100644 --- a/Documentation/filesystems/sharedsubtree.txt +++ b/Documentation/filesystems/sharedsubtree.txt @@ -837,6 +837,9 @@ replicas continue to be exactly same. individual lists does not affect propagation or the way propagation tree is modified by operations. + All vfsmounts in a peer group have the same ->mnt_master. If it is + non-NULL, they form a contiguous (ordered) segment of slave list. + A example propagation tree looks as shown in the figure below. [ NOTE: Though it looks like a forest, if we consider all the shared mounts as a conceptual entity called 'pnode', it becomes a tree] @@ -874,8 +877,19 @@ replicas continue to be exactly same. NOTE: The propagation tree is orthogonal to the mount tree. +8B Locking: + + ->mnt_share, ->mnt_slave, ->mnt_slave_list, ->mnt_master are protected + by namespace_sem (exclusive for modifications, shared for reading). + + Normally we have ->mnt_flags modifications serialized by vfsmount_lock. + There are two exceptions: do_add_mount() and clone_mnt(). + The former modifies a vfsmount that has not been visible in any shared + data structures yet. + The latter holds namespace_sem and the only references to vfsmount + are in lists that can't be traversed without namespace_sem. -8B Algorithm: +8C Algorithm: The crux of the implementation resides in rbind/move operation. |