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| author | kib <kib@FreeBSD.org> | 2015-06-10 02:20:58 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2015-06-10 02:20:58 +0000 |
| commit | 2187b2a06e2c4352326b9615e46b8efb66e5030d (patch) | |
| tree | 91e211e46c9e2bb4a48f18b201a2f0ee2439a79e | |
| parent | a105f5d7fd400b5c08d8493a9d051428dfa6d646 (diff) | |
| download | FreeBSD-src-2187b2a06e2c4352326b9615e46b8efb66e5030d.zip FreeBSD-src-2187b2a06e2c4352326b9615e46b8efb66e5030d.tar.gz | |
MFC r283601:
Add V_MNTREF flag, to indicate that caller of vn_start*_write() already
owns a reference on the mount point, and the functions can consume it.
| -rw-r--r-- | sys/kern/vfs_vnops.c | 20 | ||||
| -rw-r--r-- | sys/sys/vnode.h | 1 |
2 files changed, 11 insertions, 10 deletions
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index 1965375..ace8e5c 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -1619,14 +1619,14 @@ unlock: } int -vn_start_write(vp, mpp, flags) - struct vnode *vp; - struct mount **mpp; - int flags; +vn_start_write(struct vnode *vp, struct mount **mpp, int flags) { struct mount *mp; int error; + KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), + ("V_MNTREF requires mp")); + error = 0; /* * If a vnode is provided, get and return the mount point that @@ -1651,7 +1651,7 @@ vn_start_write(vp, mpp, flags) * emulate a vfs_ref(). */ MNT_ILOCK(mp); - if (vp == NULL) + if (vp == NULL && (flags & V_MNTREF) == 0) MNT_REF(mp); return (vn_start_write_locked(mp, flags)); @@ -1665,14 +1665,14 @@ vn_start_write(vp, mpp, flags) * time, these operations are halted until the suspension is over. */ int -vn_start_secondary_write(vp, mpp, flags) - struct vnode *vp; - struct mount **mpp; - int flags; +vn_start_secondary_write(struct vnode *vp, struct mount **mpp, int flags) { struct mount *mp; int error; + KASSERT((flags & V_MNTREF) == 0 || (*mpp != NULL && vp == NULL), + ("V_MNTREF requires mp")); + retry: if (vp != NULL) { if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { @@ -1697,7 +1697,7 @@ vn_start_secondary_write(vp, mpp, flags) * emulate a vfs_ref(). */ MNT_ILOCK(mp); - if (vp == NULL) + if (vp == NULL && (flags & V_MNTREF) == 0) MNT_REF(mp); if ((mp->mnt_kern_flag & (MNTK_SUSPENDED | MNTK_SUSPEND2)) == 0) { mp->mnt_secondary_writes++; diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h index 71b129e..fe4c9ea 100644 --- a/sys/sys/vnode.h +++ b/sys/sys/vnode.h @@ -395,6 +395,7 @@ extern int vttoif_tab[]; #define V_WAIT 0x0001 /* vn_start_write: sleep for suspend */ #define V_NOWAIT 0x0002 /* vn_start_write: don't sleep for suspend */ #define V_XSLEEP 0x0004 /* vn_start_write: just return after sleep */ +#define V_MNTREF 0x0010 /* vn_start_write: mp is already ref-ed */ #define VR_START_WRITE 0x0001 /* vfs_write_resume: start write atomically */ #define VR_NO_SUSPCLR 0x0002 /* vfs_write_resume: do not clear suspension */ |
