Date: Thu, 13 Oct 2011 12:26:36 GMT From: John Baldwin <jhb@FreeBSD.org> To: Perforce Change Reviews <perforce@freebsd.org> Subject: PERFORCE change 200144 for review Message-ID: <201110131226.p9DCQaOs052683@skunkworks.freebsd.org>
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http://p4web.freebsd.org/@@200144?ac=10 Change 200144 by jhb@jhb_jhbbsd on 2011/10/13 12:26:33 - Store (start, end) rather than (start, len) for the fadvise range. This makes some of the logic simpler. - Properly handle a length of 0 (means to EOF) for FADV_*NEED. Affected files ... .. //depot/projects/fadvise/sys/kern/vfs_syscalls.c#3 edit .. //depot/projects/fadvise/sys/sys/file.h#3 edit Differences ... ==== //depot/projects/fadvise/sys/kern/vfs_syscalls.c#3 (text+ko) ==== @@ -4895,14 +4895,18 @@ error = ENODEV; goto out; } + if (uap->len == 0) + end = OFF_MAX; + else + end = uap->offset + uap->len - 1; switch (uap->advice) { case FADV_SEQUENTIAL: case FADV_RANDOM: case FADV_NOREUSE: mtx_pool_lock(mtxpool_sleep, fp); fp->f_advice = uap->advice; - fp->f_adviceoff = uap->offset; - fp->f_advicelen = uap->len; + fp->f_advstart = uap->offset; + fp->f_advend = end; mtx_pool_unlock(mtxpool_sleep, fp); break; case FADV_NORMAL: @@ -4913,34 +4917,26 @@ */ mtx_pool_lock(mtxpool_sleep, fp); if (fp->f_advice != FADV_NORMAL) { - if (uap->len == 0 && fp->f_advicelen == 0) { - if (uap->offset > fp->f_adviceoff) - fp->f_advicelen = - uap->offset - fp->f_adviceoff; - else - fp->f_advice = FADV_NORMAL; - } else if (uap->len == 0) { - if (uap->offset <= fp->f_adviceoff) - fp->f_advice = FADV_NORMAL; - else if (fp->f_adviceoff + fp->f_advicelen > - uap->offset) - fp->f_advicelen = - uap->offset - fp->f_adviceoff; - } else if (fp->f_advicelen == 0) { - if (uap->offset + uap->len > fp->f_adviceoff) - fp->f_adviceoff = - uap->offset + uap->len; - } else if (fp->f_adviceoff < uap->offset + uap->len && - fp->f_adviceoff + fp->f_advicelen > uap->offset) - fp->f_advicelen = - uap->offset - fp->f_adviceoff; - else if (uap->offset < - fp->f_adviceoff + fp->f_advicelen && - uap->offset + uap->len > fp->f_adviceoff) { - newoff = uap->offset + uap->len - fp->f_advicelen -= (fp->f_adviceoff - newoff); - fp->f_adviceoff = newoff; - } + if (uap->offset <= fp->f_advstart && + end >= fp->f_advend) + fp->f_advice = FADV_NORMAL; + else if (uap->offset >= fp->f_advstart && + end <= fp->f_advend) + /* + * If the "normal" region is a middle + * portion of the existing + * non-standard region, just remove + * the whole thing rather than picking + * one side or the other to + * preserve. + */ + fp->f_advice = FADV_NORMAL; + else if (uap->offset <= fp->f_advstart && + end >= fp->f_advstart) + fp->f_advstart = end + 1; + else if (uap->offset <= fp->f_advend && + end >= fp->f_advstart) + fp->f_advend = uap->offset - 1; } mtx_pool_unlock(mtxpool_sleep, fp); break; @@ -4952,7 +4948,7 @@ * madvise(2) constants. */ start = trunc_page(uap->offset); - end = round_page(uap->offset + uap->len - 1); + end = round_page(end); vfslocked = VFS_LOCK_GIANT(vp->v_mount); vn_lock(vp, LK_SHARED | LK_RETRY); if (vp->v_object != NULL) ==== //depot/projects/fadvise/sys/sys/file.h#3 (text+ko) ==== @@ -138,8 +138,8 @@ off_t f_nextoff; /* next expected read/write offset. */ struct cdev_privdata *f_cdevpriv; /* (d) Private data for the cdev. */ int f_advice; /* (f) FADV_* type. */ - off_t f_adviceoff; /* (f) fadvice regionoffset. */ - off_t f_advicelen; /* (f) fadvice region length. */ + off_t f_advstart; /* (f) fadvice region start. */ + off_t f_advend; /* (f) fadvice region end. */ /* * DFLAG_SEEKABLE specific fields */
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