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fstat: fix fsid comparison when executed on systems with 64-bit long

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This affects only fstat on zfs and devfs, only on 64-bit systems
and only when fsid is greater than 2^31 - 1.
When fstat examines a file via stat(2) it takes uint32_t st_dev
and assigns to (signed) (64-bit) long fsid, this results in
a positive value.
When fstat examines opened files it takes int32_t f_fsid.val[0]
and assigns to (signed) (64-bit) long fsid, this results in
a negative value.
So, while initially st_dev and f_fsid.val[0] have the same bit
values they get promoted to different 64-bit values because
of the signed-vs-unsigned difference.

A fix is to use "more natural" positive numbers by introducing
intermediate unsigned cast for f_fsid.val[0].

Reviewed by:	jhb, lulf
Approved by:	re (kib)
MFC after:	1 week (to stable/7)
This commit is contained in:
Andriy Gapon 2009-08-20 10:57:14 +00:00
parent 52e12426d1
commit 497e910cd3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=196399
2 changed files with 2 additions and 2 deletions
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2
usr.bin/fstat/fstat.c
View File

@ -658,7 +658,7 @@ devfs_filestat(struct vnode *vp, struct filestat *fsp)
(void *)devfs_dirent.de_vnode, Pid);
return 0;
}
fsp->fsid = (long)mount.mnt_stat.f_fsid.val[0];
fsp->fsid = (long)(uint32_t)mount.mnt_stat.f_fsid.val[0];
fsp->fileid = devfs_dirent.de_inode;
fsp->mode = (devfs_dirent.de_mode & ~S_IFMT) | S_IFCHR;
fsp->size = 0;

2
usr.bin/fstat/zfs.c
View File

@ -117,7 +117,7 @@ zfs_filestat(struct vnode *vp, struct filestat *fsp)
goto bad;
}
fsp->fsid = (long)mount.mnt_stat.f_fsid.val[0];
fsp->fsid = (long)(uint32_t)mount.mnt_stat.f_fsid.val[0];
fsp->fileid = *zid;
/*
* XXX: Shows up wrong in output, but UFS has this error too. Could