diff options
author | Pavel Shilovsky <piastry@etersoft.ru> | 2012-03-05 10:39:20 +0400 |
---|---|---|
committer | Steve French <sfrench@us.ibm.com> | 2012-03-07 07:50:15 +0400 |
commit | d5751469f210d2149cc2159ffff66cbeef6da3f2 (patch) | |
tree | 7d5e9af79050cfe56e4412d6ebdd90dfce55c8d9 /fs/cifs | |
parent | b0f8ef202ec7f07ba9bd93150d54ef4327851422 (diff) | |
download | linux-d5751469f210d2149cc2159ffff66cbeef6da3f2.tar.xz |
CIFS: Do not kmalloc under the flocks spinlock
Reorganize the code to make the memory already allocated before
spinlock'ed loop.
Cc: stable@vger.kernel.org
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r-- | fs/cifs/file.c | 69 |
1 files changed, 56 insertions, 13 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 4dd9283885e7..5e64748a2917 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -920,16 +920,26 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile) for (lockp = &inode->i_flock; *lockp != NULL; \ lockp = &(*lockp)->fl_next) +struct lock_to_push { + struct list_head llist; + __u64 offset; + __u64 length; + __u32 pid; + __u16 netfid; + __u8 type; +}; + static int cifs_push_posix_locks(struct cifsFileInfo *cfile) { struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode); struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); struct file_lock *flock, **before; - struct cifsLockInfo *lck, *tmp; + unsigned int count = 0, i = 0; int rc = 0, xid, type; + struct list_head locks_to_send, *el; + struct lock_to_push *lck, *tmp; __u64 length; - struct list_head locks_to_send; xid = GetXid(); @@ -940,29 +950,55 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile) return rc; } + lock_flocks(); + cifs_for_each_lock(cfile->dentry->d_inode, before) { + if ((*before)->fl_flags & FL_POSIX) + count++; + } + unlock_flocks(); + INIT_LIST_HEAD(&locks_to_send); + /* + * Allocating count locks is enough because no locks can be added to + * the list while we are holding cinode->lock_mutex that protects + * locking operations of this inode. + */ + for (; i < count; i++) { + lck = kmalloc(sizeof(struct lock_to_push), GFP_KERNEL); + if (!lck) { + rc = -ENOMEM; + goto err_out; + } + list_add_tail(&lck->llist, &locks_to_send); + } + + i = 0; + el = locks_to_send.next; lock_flocks(); cifs_for_each_lock(cfile->dentry->d_inode, before) { + if (el == &locks_to_send) { + /* something is really wrong */ + cERROR(1, "Can't push all brlocks!"); + break; + } flock = *before; + if ((flock->fl_flags & FL_POSIX) == 0) + continue; length = 1 + flock->fl_end - flock->fl_start; if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK) type = CIFS_RDLCK; else type = CIFS_WRLCK; - - lck = cifs_lock_init(flock->fl_start, length, type, - cfile->netfid); - if (!lck) { - rc = -ENOMEM; - goto send_locks; - } + lck = list_entry(el, struct lock_to_push, llist); lck->pid = flock->fl_pid; - - list_add_tail(&lck->llist, &locks_to_send); + lck->netfid = cfile->netfid; + lck->length = length; + lck->type = type; + lck->offset = flock->fl_start; + i++; + el = el->next; } - -send_locks: unlock_flocks(); list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) { @@ -979,11 +1015,18 @@ send_locks: kfree(lck); } +out: cinode->can_cache_brlcks = false; mutex_unlock(&cinode->lock_mutex); FreeXid(xid); return rc; +err_out: + list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) { + list_del(&lck->llist); + kfree(lck); + } + goto out; } static int |