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| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-04-28 19:35:16 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2016-05-02 19:51:17 -0400 |
| commit | 9cf843e3f47c41440367062e92ab32e59ecb6a87 (patch) | |
| tree | c661c0dde1141aee43d8d406bd573d4ffcaafa95 | |
| parent | 6fbd07146d99239547cd4970622c96e9cb0f3213 (diff) | |
| download | linux-9cf843e3f47c41440367062e92ab32e59ecb6a87.tar.bz2 | |
lookup_open(): lock the parent shared unless O_CREAT is given
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | Documentation/filesystems/porting | 3 | ||||
| -rw-r--r-- | fs/namei.c | 12 |
2 files changed, 12 insertions, 3 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 12c57abdaac9..46f3bb7a02f5 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -575,3 +575,6 @@ in your dentry operations instead. Old method is only used if the new one is absent; eventually it will be removed. Switch while you still can; the old one won't stay. +-- +[mandatory] + ->atomic_open() calls without O_CREAT may happen in parallel. diff --git a/fs/namei.c b/fs/namei.c index b84e6b2e19e9..01069ddda3e3 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3084,7 +3084,7 @@ static int do_last(struct nameidata *nd, } retry_lookup: - if (op->open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) { + if (open_flag & (O_CREAT | O_TRUNC | O_WRONLY | O_RDWR)) { error = mnt_want_write(nd->path.mnt); if (!error) got_write = true; @@ -3094,9 +3094,15 @@ retry_lookup: * dropping this one anyway. */ } - inode_lock(dir->d_inode); + if (open_flag & O_CREAT) + inode_lock(dir->d_inode); + else + inode_lock_shared(dir->d_inode); error = lookup_open(nd, &path, file, op, got_write, opened); - inode_unlock(dir->d_inode); + if (open_flag & O_CREAT) + inode_unlock(dir->d_inode); + else + inode_unlock_shared(dir->d_inode); if (error <= 0) { if (error) |