| Message ID | 20100430082936.5630.67682.sendpatchset@localhost.localdomain |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, Apr 30, 2010 at 4:25 PM, Amerigo Wang <amwang@redhat.com> wrote: > From: Octavian Purdila <opurdila@ixiacom.com> > > 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 into the file will first reset the bitmap then update it > based on the given input. > > Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> > Signed-off-by: WANG Cong <amwang@redhat.com> > Cc: Eric W. Biederman <ebiederm@xmission.com> > --- > > Index: linux-2.6/include/linux/sysctl.h > =================================================================== > --- linux-2.6.orig/include/linux/sysctl.h > +++ linux-2.6/include/linux/sysctl.h > @@ -980,6 +980,8 @@ extern int proc_doulongvec_minmax(struct > 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 > Index: linux-2.6/kernel/sysctl.c > =================================================================== > --- linux-2.6.orig/kernel/sysctl.c > +++ linux-2.6/kernel/sysctl.c > @@ -2049,6 +2049,16 @@ static size_t proc_skip_spaces(char **bu > return ret; > } > > +static void proc_skip_char(char **buf, size_t *size, const char v) > +{ > + while (*size) { > + if (**buf != v) > + break; > + (*size)--; > + (*buf)++; > + } > +} > + > #define TMPBUFLEN 22 > /** > * proc_get_long - reads an ASCII formated integer from a user buffer > @@ -2675,6 +2685,153 @@ static int proc_do_cad_pid(struct ctl_ta > 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) > +{ > + int err = 0; > + bool first = 1; > + size_t left = *lenp; > + unsigned long bitmap_len = table->maxlen; > + unsigned long *bitmap = (unsigned long *) table->data; > + unsigned long *tmp_bitmap = NULL; > + char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c; > + > + if (!bitmap_len || !left || (*ppos && !write)) { > + *lenp = 0; > + return 0; > + } > + > + if (write) { > + unsigned long page = 0; > + char *kbuf; > + > + if (left > PAGE_SIZE - 1) > + left = PAGE_SIZE - 1; > + > + page = __get_free_page(GFP_TEMPORARY); > + kbuf = (char *) page; > + if (!kbuf) > + return -ENOMEM; > + if (copy_from_user(kbuf, buffer, left)) { > + free_page(page); > + return -EFAULT; > + } > + kbuf[left] = 0; > + > + tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long), > + GFP_KERNEL); > + if (!tmp_bitmap) { > + free_page(page); > + return -ENOMEM; > + } > + proc_skip_char(&kbuf, &left, '\n'); > + while (!err && left) { > + unsigned long val_a, val_b; > + bool neg; > + > + err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a, > + sizeof(tr_a), &c); > + if (err) > + break; > + if (val_a >= bitmap_len || neg) { > + err = -EINVAL; > + break; > + } > + > + val_b = val_a; > + if (left) { > + kbuf++; > + left--; > + } > + > + if (c == '-') { > + err = proc_get_long(&kbuf, &left, &val_b, > + &neg, tr_b, sizeof(tr_b), > + &c); > + if (err) > + break; > + if (val_b >= bitmap_len || neg || > + val_a > val_b) { > + err = -EINVAL; > + break; > + } > + if (left) { > + kbuf++; > + left--; > + } > + } > + > + while (val_a <= val_b) > + set_bit(val_a++, tmp_bitmap); > + > + first = 0; > + proc_skip_char(&kbuf, &left, '\n'); > + } > + free_page(page); > + } 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; > + > + if (!first) { > + err = proc_put_char(&buffer, &left, ','); > + if (err) > + break; > + } > + err = proc_put_long(&buffer, &left, bit_a, false); > + if (err) > + break; > + if (bit_a != bit_b) { > + err = proc_put_char(&buffer, &left, '-'); > + if (err) > + break; > + err = proc_put_long(&buffer, &left, bit_b, false); > + if (err) > + break; > + } > + > + first = 0; bit_b++; > + } > + if (!err) > + err = proc_put_char(&buffer, &left, '\n'); > + } > + > + if (!err) { add the following lines to let "echo 1-10 >> /proc/..." work as normal. if (write && *ppos) bimap_or(bitmap, bitmap, tmp_bitmap,....) else > + if (write) > + memcpy(bitmap, tmp_bitmap, > + BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long)); > + kfree(tmp_bitmap); > + *lenp -= left; > + *ppos += *lenp; > + return 0;
Changli Gao wrote: > add the following lines to let "echo 1-10 >> > /proc/..." work as normal. Hmm, I haven't tested this, what did you see if we append lines into it? Also, do we need appending lines to this /proc file when design it? Octavian? Eric? Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Cong Wang wrote: > Changli Gao wrote: >> add the following lines to let "echo 1-10 >> >> /proc/..." work as normal. > > Hmm, I haven't tested this, what did you see if we append > lines into it? > > Also, do we need appending lines to this /proc file when design it? > Octavian? Eric? > Hmm, currently this behaves like other /proc files, IOW, echo 'foo' >> /proc/XXX is the same with echo 'foo' > /proc/XXX. I think it is reasonable for bitmap /proc files to have echo 'foo' >> /proc/XXX behaves like non-proc files, that is appending numbers into that file, like what Changli mentioned. Any objections? Thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-2.6/include/linux/sysctl.h =================================================================== --- linux-2.6.orig/include/linux/sysctl.h +++ linux-2.6/include/linux/sysctl.h @@ -980,6 +980,8 @@ extern int proc_doulongvec_minmax(struct 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 Index: linux-2.6/kernel/sysctl.c =================================================================== --- linux-2.6.orig/kernel/sysctl.c +++ linux-2.6/kernel/sysctl.c @@ -2049,6 +2049,16 @@ static size_t proc_skip_spaces(char **bu return ret; } +static void proc_skip_char(char **buf, size_t *size, const char v) +{ + while (*size) { + if (**buf != v) + break; + (*size)--; + (*buf)++; + } +} + #define TMPBUFLEN 22 /** * proc_get_long - reads an ASCII formated integer from a user buffer @@ -2675,6 +2685,153 @@ static int proc_do_cad_pid(struct ctl_ta 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) +{ + int err = 0; + bool first = 1; + size_t left = *lenp; + unsigned long bitmap_len = table->maxlen; + unsigned long *bitmap = (unsigned long *) table->data; + unsigned long *tmp_bitmap = NULL; + char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c; + + if (!bitmap_len || !left || (*ppos && !write)) { + *lenp = 0; + return 0; + } + + if (write) { + unsigned long page = 0; + char *kbuf; + + if (left > PAGE_SIZE - 1) + left = PAGE_SIZE - 1; + + page = __get_free_page(GFP_TEMPORARY); + kbuf = (char *) page; + if (!kbuf) + return -ENOMEM; + if (copy_from_user(kbuf, buffer, left)) { + free_page(page); + return -EFAULT; + } + kbuf[left] = 0; + + tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long), + GFP_KERNEL); + if (!tmp_bitmap) { + free_page(page); + return -ENOMEM; + } + proc_skip_char(&kbuf, &left, '\n'); + while (!err && left) { + unsigned long val_a, val_b; + bool neg; + + err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a, + sizeof(tr_a), &c); + if (err) + break; + if (val_a >= bitmap_len || neg) { + err = -EINVAL; + break; + } + + val_b = val_a; + if (left) { + kbuf++; + left--; + } + + if (c == '-') { + err = proc_get_long(&kbuf, &left, &val_b, + &neg, tr_b, sizeof(tr_b), + &c); + if (err) + break; + if (val_b >= bitmap_len || neg || + val_a > val_b) { + err = -EINVAL; + break; + } + if (left) { + kbuf++; + left--; + } + } + + while (val_a <= val_b) + set_bit(val_a++, tmp_bitmap); + + first = 0; + proc_skip_char(&kbuf, &left, '\n'); + } + free_page(page); + } 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; + + if (!first) { + err = proc_put_char(&buffer, &left, ','); + if (err) + break; + } + err = proc_put_long(&buffer, &left, bit_a, false); + if (err) + break; + if (bit_a != bit_b) { + err = proc_put_char(&buffer, &left, '-'); + if (err) + break; + err = proc_put_long(&buffer, &left, bit_b, false); + if (err) + break; + } + + first = 0; bit_b++; + } + if (!err) + err = proc_put_char(&buffer, &left, '\n'); + } + + if (!err) { + if (write) + memcpy(bitmap, tmp_bitmap, + BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long)); + kfree(tmp_bitmap); + *lenp -= left; + *ppos += *lenp; + return 0; + } else { + kfree(tmp_bitmap); + return err; + } +} + #else /* CONFIG_PROC_FS */ int proc_dostring(struct ctl_table *table, int write,