The branch main has been updated by rmacklem:
URL:
https://cgit.FreeBSD.org/src/commit/?id=89f1dcb3eb468e4cbaebd1ccde9a643d85f1282e
commit 89f1dcb3eb468e4cbaebd1ccde9a643d85f1282e
Author: Rick Macklem <rmack...@freebsd.org>
AuthorDate: 2024-03-15 00:35:32 +0000
Commit: Rick Macklem <rmack...@freebsd.org>
CommitDate: 2024-03-15 00:35:32 +0000
vfs_vnops.c: Use va_bytes >= va_size hint to avoid SEEK_DATA/SEEKHOLE
vn_generic_copy_file_range() tries to maintain holes
in file ranges being copied, using SEEK_DATA/SEEK_HOLE
where possible,
Unfortunately SEEK_DATA/SEEK_HOLE operations can take
a long time under certain circumstances.
Although it is not currently possible to know if a file has
unallocated data regions, the case where va_bytes >= va_size
is a strong hint that there are no unallocated data regions.
This hint does not work well for file systems doing compression,
but since it is only a hint, it is still useful.
For the case of va_bytes >= va_size, avoid doing SEEK_DATA/SEEK_HOLE.
Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D44509
---
sys/kern/vfs_vnops.c | 34 ++++++++++++++++++++++++++--------
1 file changed, 26 insertions(+), 8 deletions(-)
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index fd78b692b088..d79707555ac1 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -3334,14 +3334,15 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
struct vnode *outvp, off_t *outoffp, size_t *lenp, unsigned int flags,
struct ucred *incred, struct ucred *outcred, struct thread *fsize_td)
{
+ struct vattr inva;
struct mount *mp;
off_t startoff, endoff, xfer, xfer2;
u_long blksize;
int error, interrupted;
- bool cantseek, readzeros, eof, lastblock, holetoeof;
+ bool cantseek, readzeros, eof, lastblock, holetoeof, sparse;
ssize_t aresid, r = 0;
size_t copylen, len, savlen;
- off_t insize, outsize;
+ off_t outsize;
char *dat;
long holein, holeout;
struct timespec curts, endts;
@@ -3357,11 +3358,26 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
goto out;
if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
holein = 0;
- error = vn_getsize_locked(invp, &insize, incred);
+ error = VOP_GETATTR(invp, &inva, incred);
+ if (error == 0 && inva.va_size > OFF_MAX)
+ error = EFBIG;
VOP_UNLOCK(invp);
if (error != 0)
goto out;
+ /*
+ * Use va_bytes >= va_size as a hint that the file does not have
+ * sufficient holes to justify the overhead of doing FIOSEEKHOLE.
+ * This hint does not work well for file systems doing compression
+ * and may fail when allocations for extended attributes increases
+ * the value of va_bytes to >= va_size.
+ */
+ sparse = true;
+ if (holein != 0 && inva.va_bytes >= inva.va_size) {
+ holein = 0;
+ sparse = false;
+ }
+
mp = NULL;
error = vn_start_write(outvp, &mp, V_WAIT);
if (error == 0)
@@ -3395,9 +3411,9 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
error = vn_getsize_locked(outvp, &outsize, outcred);
if (error == 0 && outsize > *outoffp &&
*outoffp <= OFF_MAX - len && outsize <= *outoffp + len &&
- *inoffp < insize &&
- *outoffp <= OFF_MAX - (insize - *inoffp) &&
- outsize <= *outoffp + (insize - *inoffp)) {
+ *inoffp < inva.va_size &&
+ *outoffp <= OFF_MAX - (inva.va_size - *inoffp) &&
+ outsize <= *outoffp + (inva.va_size - *inoffp)) {
#ifdef MAC
error = mac_vnode_check_write(curthread->td_ucred,
outcred, outvp);
@@ -3415,7 +3431,7 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
if (error != 0)
goto out;
- if (holein == 0 && holeout > 0) {
+ if (sparse && holein == 0 && holeout > 0) {
/*
* For this special case, the input data will be scanned
* for blocks of all 0 bytes. For these blocks, the
@@ -3486,7 +3502,7 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
error = VOP_IOCTL(invp, FIOSEEKDATA, &startoff, 0,
incred, curthread);
if (error == ENXIO) {
- startoff = endoff = insize;
+ startoff = endoff = inva.va_size;
eof = holetoeof = true;
error = 0;
}
@@ -3549,6 +3565,8 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
cantseek = false;
} else {
cantseek = true;
+ if (!sparse)
+ cantseek = false;
startoff = *inoffp;
copylen = len;
error = 0;
