Revert behavior of 59eab109 on not-Linux

It turns out that short-circuiting the EFAULT behavior on a short read
breaks things on FreeBSD. So until there's a nicer solution, let's
just revert the behavior for not-Linux.

Reference:
https://reviews.freebsd.org/R10:70f51f0e474ffe1fb74cb427423a2fba3637544d

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Brian Atkinson <batkinson@lanl.gov>
Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
Closes #12698
This commit is contained in:
Rich Ercolani 2021-11-04 09:49:40 -04:00 committed by GitHub
parent e79b6807b8
commit 05679465ac
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@ -254,7 +254,9 @@ zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
}
ASSERT(zfs_uio_offset(uio) < zp->z_size);
#if defined(__linux__)
ssize_t start_offset = zfs_uio_offset(uio);
#endif
ssize_t n = MIN(zfs_uio_resid(uio), zp->z_size - zfs_uio_offset(uio));
ssize_t start_resid = n;
@ -277,13 +279,18 @@ zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
/* convert checksum errors into IO errors */
if (error == ECKSUM)
error = SET_ERROR(EIO);
#if defined(__linux__)
/*
* if we actually read some bytes, bubbling EFAULT
* up to become EAGAIN isn't what we want here.
* up to become EAGAIN isn't what we want here...
*
* ...on Linux, at least. On FBSD, doing this breaks.
*/
if (error == EFAULT &&
(zfs_uio_offset(uio) - start_offset) != 0)
error = 0;
#endif
break;
}