LU-10092 pcc: Non-blocking PCC caching

[fs/lustre-release.git] / lustre / llite / dir.c

diff --git a/lustre/llite/dir.c b/lustre/llite/dir.c
index c70cd20..b5cbb7e 100644 (file)
--- a/lustre/llite/dir.c
+++ b/lustre/llite/dir.c
@@ -1983,41 +1983,12 @@ migrate_free:
                RETURN(ll_ioctl_fsgetxattr(inode, cmd, arg));
        case LL_IOC_FSSETXATTR:
                RETURN(ll_ioctl_fssetxattr(inode, cmd, arg));
-       case LL_IOC_PCC_DETACH: {
+       case LL_IOC_PCC_DETACH_BY_FID: {
                struct lu_pcc_detach *detach;
                struct lu_fid *fid;
                struct inode *inode2;
                unsigned long ino;
 
-               /*
-                * The reason why a dir IOCTL is used to detach a PCC-cached
-                * file rather than making it a file IOCTL is:
-                * When PCC caching a file, it will attach the file firstly,
-                * and increase the refcount of PCC inode (pcci->pcci_refcount)
-                * from 0 to 1.
-                * When detaching a PCC-cached file, it will check whether the
-                * refcount is 1. If so, the file can be detached successfully.
-                * Otherwise, it means there are some users opened and using
-                * the file currently, and it will return -EBUSY.
-                * Each open on the PCC-cached file will increase the refcount
-                * of the PCC inode;
-                * Each close on the PCC-cached file will decrease the refcount
-                * of the PCC inode;
-                * When used a file IOCTL to detach a PCC-cached file, it needs
-                * to open it at first, which will increase the refcount. So
-                * during the process of the detach IOCTL, it will return
-                * -EBUSY as the PCC inode refcount is larger than 1. Someone
-                * might argue that here it can just decrease the refcount
-                * of the PCC inode, return succeed and make the close of
-                * IOCTL file handle to perform the real detach. But this
-                * may result in inconsistent state of a PCC file. i.e. Process
-                * A got a successful return form the detach IOCTL; Process B
-                * opens the file before Process A finally closed the IOCTL
-                * file handle. It makes the following I/O of Process B will
-                * direct into PCC although the file was already detached from
-                * the view of Process A.
-                * Using a dir IOCTL does not exist the problem above.
-                */
                OBD_ALLOC_PTR(detach);
                if (detach == NULL)
                        RETURN(-ENOMEM);