Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752235Ab0BXFUh (ORCPT ); Wed, 24 Feb 2010 00:20:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32357 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567Ab0BXFUc (ORCPT ); Wed, 24 Feb 2010 00:20:32 -0500 Message-ID: <4B84B7F0.7090709@redhat.com> Date: Wed, 24 Feb 2010 13:24:00 +0800 From: Cong Wang User-Agent: Thunderbird 2.0.0.23 (X11/20091001) MIME-Version: 1.0 To: Octavian Purdila CC: David Miller , Linux Kernel Network Developers , Linux Kernel Developers , "Eric W. Biederman" Subject: Re: [net-next PATCH v5 2/3] sysctl: add proc_do_large_bitmap References: <1266752533.3428.28.camel@Nokia-N900-42-11> <4B81EFD8.8020202@redhat.com> <201002221829.13987.opurdila@ixiacom.com> In-Reply-To: <201002221829.13987.opurdila@ixiacom.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5566 Lines: 214 Octavian Purdila wrote: > > Here is a new version of this patch which fixes both the comma and invalid > value issues, please give it a try. > Sorry, it is even worse. :( > [net-next PATCH v5 2/3] sysctl: add proc_do_large_bitmap > > The new function can be used to read/write large bitmaps via /proc. A > comma separated range format is used for compact output and input > (e.g. 1,3-4,10-10). > Writing "50000-50100" gets EINVAL, it should be success. Writing "50000,50100" fails too. Please, at least, do some basic testing. Also some comments below. > Writing into the file will first reset the bitmap then update it > based on the given input. > > Signed-off-by: Octavian Purdila > Cc: WANG Cong > Cc: Eric W. Biederman Please resend the whole patchset, and update the doc in patch 3/3. > --- > include/linux/sysctl.h | 2 + > kernel/sysctl.c | 134 > ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 136 insertions(+), 0 deletions(-) > > diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h > index f66014c..7bb5cb6 100644 > --- a/include/linux/sysctl.h > +++ b/include/linux/sysctl.h > @@ -980,6 +980,8 @@ extern int proc_doulongvec_minmax(struct ctl_table *, int, > void __user *, size_t *, loff_t *); > extern int proc_doulongvec_ms_jiffies_minmax(struct ctl_table *table, int, > void __user *, size_t *, loff_t *); > +extern int proc_do_large_bitmap(struct ctl_table *, int, > + void __user *, size_t *, loff_t *); > > /* > * Register a set of sysctl names by calling register_sysctl_table > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 5259727..d8ea839 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -2635,6 +2635,140 @@ static int proc_do_cad_pid(struct ctl_table *table, > int write, The above line is wrong, it should be a part of previous line. > return 0; > } > > +/** > + * proc_do_large_bitmap - read/write from/to a large bitmap > + * @table: the sysctl table > + * @write: %TRUE if this is a write to the sysctl file > + * @buffer: the user buffer > + * @lenp: the size of the user buffer > + * @ppos: file position > + * > + * The bitmap is stored at table->data and the bitmap length (in bits) > + * in table->maxlen. > + * > + * We use a range comma separated format (e.g. 1,3-4,10-10) so that > + * large bitmaps may be represented in a compact manner. Writing into > + * the file will clear the bitmap then update it with the given input. > + * > + * Returns 0 on success. > + */ > +int proc_do_large_bitmap(struct ctl_table *table, int write, > + void __user *_buffer, size_t *lenp, loff_t *ppos) > +{ > + bool first = 1; > + unsigned long *bitmap = (unsigned long *) table->data; > + unsigned long bitmap_len = table->maxlen; > + int left = *lenp, err = 0; 'left' should be size_t. > + char __user *buffer = (char __user *) _buffer; > + char tr_a[] = { '-', ',', 0 }, tr_b[] = { ',', 0 }, c; > + > + > + if (!bitmap_len || !left || (*ppos && !write)) { > + *lenp = 0; > + return 0; > + } > + > + if (write) { > + err = proc_skip_wspace(&buffer, &left); > + while (!err && left) { > + unsigned long val_a, val_b; > + bool neg; > + > + err = proc_get_ulong(&buffer, &left, tr_a, > + &val_a, &neg, &c); > + if (err) > + break; > + > + if (val_a >= bitmap_len || neg) { > + err = -EINVAL; > + break; > + } > + > + val_b = val_a; > + if (left && c == '-') { > + /* skip the - */ > + buffer++; left--; > + > + err = proc_get_ulong(&buffer, &left, tr_b, > + &val_b, &neg, &c); > + if (err) > + break; > + > + if (val_b >= bitmap_len || neg || > + val_a > val_b) { > + err = -EINVAL; > + break; > + } > + } > + > + if (left) { > + err = proc_skip_wspace(&buffer, &left); > + if (err) > + break; > + if (left) { > + if (get_user(c, buffer)) { > + err = -EFAULT; > + break; > + } > + if (c != ',') { > + err = -EINVAL; > + break; > + } > + /* skip the , */ > + buffer++; left--; > + } > + } > + > + if (first) > + bitmap_clear(bitmap, 0, bitmap_len); > + > + while (val_a <= val_b) > + set_bit(val_a++, bitmap); > + > + first = 0; > + } > + if (!err) > + err = proc_skip_wspace(&buffer, &left); > + } else { > + unsigned long bit_a, bit_b = 0; > + > + while (left) { > + bit_a = find_next_bit(bitmap, bitmap_len, bit_b); > + if (bit_a >= bitmap_len) > + break; > + bit_b = find_next_zero_bit(bitmap, bitmap_len, > + bit_a + 1) - 1; > + > + err = proc_put_ulong(&buffer, &left, bit_a, 0, first, > + ','); > + if (err) > + break; > + if (bit_a != bit_b) { > + err = proc_put_char(&buffer, &left, '-'); > + if (err) > + break; > + err = proc_put_ulong(&buffer, &left, bit_b, 0, > + 1, 0); > + if (err) > + break; > + } > + > + first = 0; bit_b++; > + } > + if (!err) > + err = proc_put_char(&buffer, &left, '\n'); > + } > + > + if (first) { > + if (err) > + return err; > + bitmap_clear(bitmap, 0, bitmap_len); > + } > + *lenp -= left; > + *ppos += *lenp; > + return 0; > +} > + > #else /* CONFIG_PROC_FS */ > > int proc_dostring(struct ctl_table *table, int write, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/