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sys/fs/unionfs/union_subr.c
| Show First 20 Lines • Show All 1,233 Lines • ▼ Show 20 Lines | #endif | ||||
| /* close vnode */ | /* close vnode */ | ||||
| VOP_CLOSE(vp, FREAD, cred, td); | VOP_CLOSE(vp, FREAD, cred, td); | ||||
| return (error); | return (error); | ||||
| } | } | ||||
| #ifdef DIAGNOSTIC | #ifdef DIAGNOSTIC | ||||
| struct vnode * | struct vnode * | ||||
| unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) | unionfs_checkuppervp(struct vnode *vp, char *fil, int lno) | ||||
| { | { | ||||
| struct unionfs_node *unp; | struct unionfs_node *unp; | ||||
| unp = VTOUNIONFS(vp); | unp = VTOUNIONFS(vp); | ||||
| #ifdef notyet | #ifdef notyet | ||||
| if (vp->v_op != unionfs_vnodeop_p) { | if (vp->v_op != unionfs_vnodeop_p) { | ||||
| printf("unionfs_checkuppervp: on non-unionfs-node.\n"); | printf("unionfs_checkuppervp: on non-unionfs-node.\n"); | ||||
| #ifdef KDB | #ifdef KDB | ||||
| kdb_enter(KDB_WHY_UNIONFS, | kdb_enter(KDB_WHY_UNIONFS, | ||||
| "unionfs_checkuppervp: on non-unionfs-node.\n"); | "unionfs_checkuppervp: on non-unionfs-node.\n"); | ||||
| #endif | #endif | ||||
| panic("unionfs_checkuppervp"); | panic("unionfs_checkuppervp"); | ||||
| } | } | ||||
| #endif | #endif | ||||
| return (unp->un_uppervp); | return (unp->un_uppervp); | ||||
| } | } | ||||
| struct vnode * | struct vnode * | ||||
| unionfs_checklowervp(struct vnode *vp, char *fil, int lno) | unionfs_checklowervp(struct vnode *vp, char *fil, int lno) | ||||
| { | { | ||||
| struct unionfs_node *unp; | struct unionfs_node *unp; | ||||
| unp = VTOUNIONFS(vp); | unp = VTOUNIONFS(vp); | ||||
| #ifdef notyet | #ifdef notyet | ||||
| if (vp->v_op != unionfs_vnodeop_p) { | if (vp->v_op != unionfs_vnodeop_p) { | ||||
| printf("unionfs_checklowervp: on non-unionfs-node.\n"); | printf("unionfs_checklowervp: on non-unionfs-node.\n"); | ||||
| #ifdef KDB | #ifdef KDB | ||||
| kdb_enter(KDB_WHY_UNIONFS, | kdb_enter(KDB_WHY_UNIONFS, | ||||
| "unionfs_checklowervp: on non-unionfs-node.\n"); | "unionfs_checklowervp: on non-unionfs-node.\n"); | ||||
| #endif | #endif | ||||
| panic("unionfs_checklowervp"); | panic("unionfs_checklowervp"); | ||||
| } | } | ||||
| #endif | #endif | ||||
| return (unp->un_lowervp); | return (unp->un_lowervp); | ||||
| } | } | ||||
| #endif | #endif | ||||
| /* | |||||
| * Attempt to mark the underlying mount for a vnode busy so that unionfs | |||||
| * can safely access it or issue VFS_* operations against it. | |||||
| * Returns NULL on failure. | |||||
| */ | |||||
| struct mount * | |||||
| unionfs_mount_trybusy(struct vnode *vp) | |||||
| { | |||||
| struct mount *mp; | |||||
| int error; | |||||
| mp = vfs_ref_from_vp(vp); | |||||
jah: Is it actually necessary to do the ref step here?
vfs_busy() appears to perform a superset of… | |||||
| if (mp == NULL) | |||||
| return (NULL); | |||||
| error = vfs_busy(mp, MBF_NOWAIT); | |||||
| if (error != 0) { | |||||
| vfs_rel(mp); | |||||
| return (NULL); | |||||
| } | |||||
| return (mp); | |||||
| } | |||||
| void | |||||
| unionfs_mount_unbusy(struct mount *mp) | |||||
| { | |||||
| if (mp != NULL) { | |||||
| vfs_unbusy(mp); | |||||
| vfs_rel(mp); | |||||
| } | |||||
| } | |||||
Is it actually necessary to do the ref step here?
vfs_busy() appears to perform a superset of what vfs_ref() does, so it seems we'd be able to just use a simple atomic load of vp->v_mount followed by a NULL check and vfs_busy().