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| author |   Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2010-06-30 19:18:50 +0530 |
|---|---|---|
| committer |   Eric Van Hensbergen <ericvh@gmail.com> | 2010-08-02 14:28:35 -0500 |
| commit | a534c8d15b1f1d0f861fc2bb9e0529bd8486ec3f (patch) | |
| tree | 0451da7a61bd7e3eb5968d65beee3243f7f51b5d /fs/9p/vfs_inode.c | |
| parent | fs/9p: Add support user. xattr (diff) | |
| download | linux-dev-a534c8d15b1f1d0f861fc2bb9e0529bd8486ec3f.tar.xz linux-dev-a534c8d15b1f1d0f861fc2bb9e0529bd8486ec3f.zip | |
fs/9p: Prevent parallel rename when doing fid_lookup
During fid lookup we need to make sure that the dentry->d_parent doesn't
change so that we can safely walk the parent dentries. To ensure that
we need to prevent cross directory rename during fid_lookup. Add a
per superblock rename_sem rw_semaphore to prevent parallel fid lookup and
rename.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Diffstat (limited to 'fs/9p/vfs_inode.c')
| -rw-r--r-- | fs/9p/vfs_inode.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 39352ef954dc..75c261fdc7b4 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -948,6 +948,7 @@ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, sb = dir->i_sb; v9ses = v9fs_inode2v9ses(dir); + /* We can walk d_parent because we hold the dir->i_mutex */ dfid = v9fs_fid_lookup(dentry->d_parent); if (IS_ERR(dfid)) return ERR_CAST(dfid); @@ -1055,27 +1056,33 @@ v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry, goto clunk_olddir; } + down_write(&v9ses->rename_sem); if (v9fs_proto_dotl(v9ses)) { retval = p9_client_rename(oldfid, newdirfid, (char *) new_dentry->d_name.name); if (retval != -ENOSYS) goto clunk_newdir; } + if (old_dentry->d_parent != new_dentry->d_parent) { + /* + * 9P .u can only handle file rename in the same directory + */ - /* 9P can only handle file rename in the same directory */ - if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) { P9_DPRINTK(P9_DEBUG_ERROR, "old dir and new dir are different\n"); retval = -EXDEV; goto clunk_newdir; } - v9fs_blank_wstat(&wstat); wstat.muid = v9ses->uname; wstat.name = (char *) new_dentry->d_name.name; retval = p9_client_wstat(oldfid, &wstat); clunk_newdir: + if (!retval) + /* successful rename */ + d_move(old_dentry, new_dentry); + up_write(&v9ses->rename_sem); p9_client_clunk(newdirfid); clunk_olddir: |