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Differential D37097 Diff 113464 sys/fs/tmpfs/tmpfs_vnops.c

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sys/fs/tmpfs/tmpfs_vnops.c

Show First 20 Lines • Show All 465 Lines • ▼ Show 20 Linestmpfs_stat(struct vop_stat_args *v)
sb->st_ctim.tv_nsec = node->tn_ctime.tv_nsec; sb->st_ctim.tv_nsec = node->tn_ctime.tv_nsec;
sb->st_birthtim.tv_sec = node->tn_birthtime.tv_sec; sb->st_birthtim.tv_sec = node->tn_birthtime.tv_sec;
sb->st_birthtim.tv_nsec = node->tn_birthtime.tv_nsec; sb->st_birthtim.tv_nsec = node->tn_birthtime.tv_nsec;
sb->st_blksize = PAGE_SIZE; sb->st_blksize = PAGE_SIZE;
sb->st_flags = node->tn_flags; sb->st_flags = node->tn_flags;
sb->st_gen = node->tn_gen; sb->st_gen = node->tn_gen;
if (vp->v_type == VREG) { if (vp->v_type == VREG) {
obj = node->tn_reg.tn_aobj; obj = node->tn_reg.tn_aobj;
sb->st_blocks = (u_quad_t)obj->resident_page_count * PAGE_SIZE; VM_OBJECT_RLOCK(obj);
} else sb->st_blocks = ptoa(node->tn_reg.tn_pages);
markjUnsubmitted
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Why can't it use obj->resident_page_count?

markj: Why can't it use `obj->resident_page_count`?
kibAuthorUnsubmitted
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Because some pages could be swapped out.

kib: Because some pages could be swapped out.
markjUnsubmitted
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Sorry, I didn't look carefully at the commit descriptions. But, how do we handle the case where a page is resident and clean, and there is a copy on swap? I think such a page must be counted twice, since the tmpfs mount size includes consumed swap space, but tmpfs does not get any notification from putpages.

markj: Sorry, I didn't look carefully at the commit descriptions. But, how do we handle the case where…
kibAuthorUnsubmitted
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No, I do not think that it should be counted twice. tn_pages must be equal to the file size - holes size.

kib: No, I do not think that it should be counted twice. tn_pages must be equal to the `file size…
markjUnsubmitted
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Should shm_stat() similarly avoid reporting holes?

markj: Should shm_stat() similarly avoid reporting holes?
kibAuthorUnsubmitted
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Do you mean s/avoid/start/? I.e., make stat(2) on shmfd report blocks as really allocated pages. In principle this would be a useful addition, which I can do after we agree on this patch.

kib: Do you mean s/avoid/start/? I.e., make stat(2) on shmfd report blocks as really allocated pages.
VM_OBJECT_RUNLOCK(obj);
markjUnsubmitted
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Is there any harm in a racy (i.e., unlocked) read?

markj: Is there any harm in a racy (i.e., unlocked) read?
kibAuthorUnsubmitted
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Unlocked read on 32bit machines would give potentially torn value. I am not sure that it worth #ifdef-ing ILP32 there. I can.

kib: Unlocked read on 32bit machines would give potentially torn value. I am not sure that it worth…
markjUnsubmitted
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I suspect it is a common-enough operation that removing the locking for !ILP32 is worthwhile.

markj: I suspect it is a common-enough operation that removing the locking for !ILP32 is worthwhile.
} else {
sb->st_blocks = node->tn_size; sb->st_blocks = node->tn_size;
}
sb->st_blocks /= S_BLKSIZE; sb->st_blocks /= S_BLKSIZE;
return (vop_stat_helper_post(v, error)); return (vop_stat_helper_post(v, error));
} }
int int
tmpfs_getattr(struct vop_getattr_args *v) tmpfs_getattr(struct vop_getattr_args *v)
{ {
struct vnode *vp = v->a_vp; struct vnode *vp = v->a_vp;
Show All 16 Linestmpfs_getattr(struct vop_getattr_args *v)
vap->va_blocksize = PAGE_SIZE; vap->va_blocksize = PAGE_SIZE;
vap->va_atime = node->tn_atime; vap->va_atime = node->tn_atime;
vap->va_mtime = node->tn_mtime; vap->va_mtime = node->tn_mtime;
vap->va_ctime = node->tn_ctime; vap->va_ctime = node->tn_ctime;
vap->va_birthtime = node->tn_birthtime; vap->va_birthtime = node->tn_birthtime;
vap->va_gen = node->tn_gen; vap->va_gen = node->tn_gen;
vap->va_flags = node->tn_flags; vap->va_flags = node->tn_flags;
vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ? vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
node->tn_rdev : NODEV; node->tn_rdev : NODEV;
if (vp->v_type == VREG) { if (vp->v_type == VREG) {
obj = node->tn_reg.tn_aobj; obj = node->tn_reg.tn_aobj;
vap->va_bytes = (u_quad_t)obj->resident_page_count * PAGE_SIZE; VM_OBJECT_RLOCK(obj);
} else vap->va_bytes = ptoa(node->tn_reg.tn_pages);
VM_OBJECT_RUNLOCK(obj);
} else {
vap->va_bytes = node->tn_size; vap->va_bytes = node->tn_size;
}
vap->va_filerev = 0; vap->va_filerev = 0;
return (0); return (0);
} }
int int
tmpfs_setattr(struct vop_setattr_args *v) tmpfs_setattr(struct vop_setattr_args *v)
{ {
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