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| author | Benjamin Coddington <bcodding@redhat.com> | 2017-06-16 11:13:00 -0400 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2017-07-13 15:58:04 -0400 |
| commit | 818a8dbe83fddff534b814a7d4e0c75b511dff2e (patch) | |
| tree | 153d8c114f65a8fb5d8c01dea04189db01a8351d /fs/nfs | |
| parent | a7a3b1e971cd806b81ecea3a234d8dae9de0add0 (diff) | |
| download | lwn-818a8dbe83fddff534b814a7d4e0c75b511dff2e.tar.gz lwn-818a8dbe83fddff534b814a7d4e0c75b511dff2e.zip | |
NFS: nfs_rename() - revalidate directories on -ERESTARTSYS
An interrupted rename will leave the old dentry behind if the rename
succeeds. Fix this by forcing a lookup the next time through
->d_revalidate.
A previous attempt at solving this problem took the approach to complete
the work of the rename asynchronously, however that approach was wrong
since it would allow the d_move() to occur after the directory's i_mutex
had been dropped by the original process.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/dir.c | 6 | ||||
| -rw-r--r-- | fs/nfs/unlink.c | 13 |
2 files changed, 18 insertions, 1 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 9688e9bb13dc..ab69ebb48350 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2056,7 +2056,11 @@ int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, } error = rpc_wait_for_completion_task(task); - if (error == 0) + if (error != 0) { + ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1; + /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */ + smp_wmb(); + } else error = task->tk_status; rpc_put_task(task); out: diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index 191aa577dd1f..e3949d93085c 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -288,6 +288,19 @@ static void nfs_async_rename_release(void *calldata) if (d_really_is_positive(data->old_dentry)) nfs_mark_for_revalidate(d_inode(data->old_dentry)); + /* The result of the rename is unknown. Play it safe by + * forcing a new lookup */ + if (data->cancelled) { + spin_lock(&data->old_dir->i_lock); + nfs_force_lookup_revalidate(data->old_dir); + spin_unlock(&data->old_dir->i_lock); + if (data->new_dir != data->old_dir) { + spin_lock(&data->new_dir->i_lock); + nfs_force_lookup_revalidate(data->new_dir); + spin_unlock(&data->new_dir->i_lock); + } + } + dput(data->old_dentry); dput(data->new_dentry); iput(data->old_dir); |