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| author | Konstantin Belousov <kib@FreeBSD.org> | 2019-11-29 14:02:32 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2019-11-29 14:02:32 +0000 |
| commit | fdc6b10d44c201f6ed52c1f323b2b4ca2eb64662 (patch) | |
| tree | 80e4edb52cb5e8abe1b3f799e6eda5f292c3f5e6 /sys | |
| parent | 9698d992306dee298e1f130fcf437a0ce9add73e (diff) | |
| download | src-fdc6b10d44c201f6ed52c1f323b2b4ca2eb64662.tar.gz src-fdc6b10d44c201f6ed52c1f323b2b4ca2eb64662.zip | |
Add a VN_OPEN_INVFS flag.
vn_open_cred() assumes that it is called from the top-level of a VFS
syscall. Writers must call bwillwrite() before locking any VFS
resource to wait for cleanup of dirty buffers.
ZFS getextattr() and setextattr() VOPs do call vn_open_cred(), which
results in wait for unrelated buffers while owning ZFS vnode lock (and
ZFS does not use buffer cache). VN_OPEN_INVFS allows caller to skip
bwillwrite.
Note that ZFS is still incorrect there, because it starts write on an
mp and locks a vnode while holding another vnode lock.
Reported by: Willem Jan Withagen <wjw@digiware.nl>
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Notes
Notes:
svn path=/head/; revision=355211
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c | 5 | ||||
| -rw-r--r-- | sys/kern/vfs_vnops.c | 3 | ||||
| -rw-r--r-- | sys/sys/vnode.h | 1 |
3 files changed, 6 insertions, 3 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c index ebcc0ad92e0f..ae37dd1fba12 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vnops.c @@ -5490,7 +5490,7 @@ vop_getextattr { flags = FREAD; NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname, xvp, td); - error = vn_open_cred(&nd, &flags, 0, 0, ap->a_cred, NULL); + error = vn_open_cred(&nd, &flags, VN_OPEN_INVFS, 0, ap->a_cred, NULL); vp = nd.ni_vp; NDFREE(&nd, NDF_ONLY_PNBUF); if (error != 0) { @@ -5627,7 +5627,8 @@ vop_setextattr { flags = FFLAGS(O_WRONLY | O_CREAT); NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname, xvp, td); - error = vn_open_cred(&nd, &flags, 0600, 0, ap->a_cred, NULL); + error = vn_open_cred(&nd, &flags, 0600, VN_OPEN_INVFS, ap->a_cred, + NULL); vp = nd.ni_vp; NDFREE(&nd, NDF_ONLY_PNBUF); if (error != 0) { diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index a0c018deb324..c69010dd9995 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -219,7 +219,8 @@ restart: ndp->ni_cnd.cn_flags |= AUDITVNODE1; if (vn_open_flags & VN_OPEN_NOCAPCHECK) ndp->ni_cnd.cn_flags |= NOCAPCHECK; - bwillwrite(); + if ((vn_open_flags & VN_OPEN_INVFS) == 0) + bwillwrite(); if ((error = namei(ndp)) != 0) return (error); if (ndp->ni_vp == NULL) { diff --git a/sys/sys/vnode.h b/sys/sys/vnode.h index 8472bc0fb7be..27dbcbc58b18 100644 --- a/sys/sys/vnode.h +++ b/sys/sys/vnode.h @@ -579,6 +579,7 @@ typedef void vop_getpages_iodone_t(void *, vm_page_t *, int, int); #define VN_OPEN_NOAUDIT 0x00000001 #define VN_OPEN_NOCAPCHECK 0x00000002 #define VN_OPEN_NAMECACHE 0x00000004 +#define VN_OPEN_INVFS 0x00000008 /* * Public vnode manipulation functions. |