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Message-Id: <1367388562-2213-3-git-send-email-phdm@macqel.be>
Date: Wed, 1 May 2013 08:09:19 +0200
From: Philippe De Muyter <phdm@...qel.be>
To: linux-kernel@...r.kernel.org
Cc: Jens Axboe <axboe@...nel.dk>, Karel Zak <kzak@...hat.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Philippe De Muyter <phdm@...qel.be>
Subject: [PATCH 2/5] partitions: Add aix lvm partitions support files
From: Philippe De Muyter <phdm@...qel.be>
adding partitions/aix.h and partitions/aix.c
Partitions (called Logical Volumes in AIX) can be non-contiguous or
even split on more than one disk. Altough we detect such partitions,
we cannot describe them to the Linux partitions layer, so we simply
discard them and issue a diagnose message.
Signed-off-by: Philippe De Muyter <phdm@...qel.be>
Cc: Karel Zak <kzak@...hat.com>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Andrew Morton <akpm@...ux-foundation.org>
---
block/partitions/aix.c | 291 ++++++++++++++++++++++++++++++++++++++++++++++++
block/partitions/aix.h | 1 +
2 files changed, 292 insertions(+), 0 deletions(-)
create mode 100644 block/partitions/aix.c
create mode 100644 block/partitions/aix.h
diff --git a/block/partitions/aix.c b/block/partitions/aix.c
new file mode 100644
index 0000000..ef46cf3
--- /dev/null
+++ b/block/partitions/aix.c
@@ -0,0 +1,291 @@
+/*
+ * fs/partitions/aix.c
+ *
+ * Copyright (C) 2012-2013 Philippe De Muyter <phdm@...qel.be>
+ */
+
+#include "check.h"
+#include "aix.h"
+
+struct lvm_rec {
+ char lvm_id[4]; /* "_LVM" */
+ char reserved4[16];
+ __be32 lvmarea_len;
+ __be32 vgda_len;
+ __be32 vgda_psn[2];
+ char reserved36[10];
+ __be16 pp_size; /* log2(pp_size) */
+ char reserved46[12];
+ __be16 version;
+ };
+
+struct vgda {
+ __be32 secs;
+ __be32 usec;
+ char reserved8[16];
+ __be16 numlvs;
+ __be16 maxlvs;
+ __be16 pp_size;
+ __be16 numpvs;
+ __be16 total_vgdas;
+ __be16 vgda_size;
+ };
+
+struct lvd {
+ __be16 lv_ix;
+ __be16 res2;
+ __be16 res4;
+ __be16 maxsize;
+ __be16 lv_state;
+ __be16 mirror;
+ __be16 mirror_policy;
+ __be16 num_lps;
+ __be16 res10[8];
+ };
+
+struct lvname {
+ char name[64];
+ };
+
+struct ppe {
+ __be16 lv_ix;
+ unsigned short res2;
+ unsigned short res4;
+ __be16 lp_ix;
+ unsigned short res8[12];
+ };
+
+struct pvd {
+ char reserved0[16];
+ __be16 pp_count;
+ char reserved18[2];
+ __be32 psn_part1;
+ char reserved24[8];
+ struct ppe ppe[1016];
+ };
+
+#define LVM_MAXLVS 256
+
+/**
+ * last_lba(): return number of last logical block of device
+ * @bdev: block device
+ *
+ * Description: Returns last LBA value on success, 0 on error.
+ * This is stored (by sd and ide-geometry) in
+ * the part[0] entry for this disk, and is the number of
+ * physical sectors available on the disk.
+ */
+static u64 last_lba(struct block_device *bdev)
+{
+ if (!bdev || !bdev->bd_inode)
+ return 0;
+ return (bdev->bd_inode->i_size >> 9) - 1ULL;
+}
+
+/**
+ * read_lba(): Read bytes from disk, starting at given LBA
+ * @state
+ * @lba
+ * @buffer
+ * @count
+ *
+ * Description: Reads @count bytes from @state->bdev into @buffer.
+ * Returns number of bytes read on success, 0 on error.
+ */
+static size_t read_lba(struct parsed_partitions *state, u64 lba, u8 * buffer, size_t count)
+{
+ size_t totalreadcount = 0;
+
+ if (!buffer || lba + count / 512 > last_lba(state->bdev))
+ return 0;
+
+ while (count) {
+ int copied = 512;
+ Sector sect;
+ unsigned char *data = read_part_sector(state, lba++, §);
+ if (!data)
+ break;
+ if (copied > count)
+ copied = count;
+ memcpy(buffer, data, copied);
+ put_dev_sector(sect);
+ buffer += copied;
+ totalreadcount +=copied;
+ count -= copied;
+ }
+ return totalreadcount;
+}
+
+/**
+ * alloc_pvd(): reads physical volume descriptor
+ * @state
+ * @lba
+ *
+ * Description: Returns pvd on success, NULL on error.
+ * Allocates space for pvd and fill it with disk blocks at @lba
+ * Notes: remember to free pvd when you're done!
+ */
+static struct pvd *alloc_pvd(struct parsed_partitions *state, u32 lba)
+{
+ size_t count = sizeof(struct pvd);
+ struct pvd *p;
+
+ p = kmalloc(count, GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ if (read_lba(state, lba, (u8 *) p, count) < count) {
+ kfree(p);
+ return NULL;
+ }
+ return p;
+}
+
+/**
+ * alloc_lvn(): reads logical volume names
+ * @state
+ * @lba
+ *
+ * Description: Returns lvn on success, NULL on error.
+ * Allocates space for lvn and fill it with disk blocks at @lba
+ * Notes: remember to free lvn when you're done!
+ */
+static struct lvname *alloc_lvn(struct parsed_partitions *state, u32 lba)
+{
+ size_t count = sizeof(struct lvname) * LVM_MAXLVS;
+ struct lvname *p;
+
+ p = kmalloc(count, GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ if (read_lba(state, lba, (u8 *) p, count) < count) {
+ kfree(p);
+ return NULL;
+ }
+ return p;
+}
+
+int aix_partition(struct parsed_partitions *state)
+{
+ int ret = 0;
+ Sector sect;
+ unsigned char *d;
+ u32 pp_bytes_size;
+ u32 pp_blocks_size = 0;
+ u32 vgda_sector = 0;
+ u32 vgda_len = 0;
+ int numlvs = 0;
+ struct pvd *pvd;
+ struct lv_info {
+ unsigned short pps_per_lv;
+ unsigned short pps_found;
+ unsigned char lv_is_contiguous;
+ } *lvip;
+ struct lvname *n = NULL;
+
+ d = read_part_sector(state, 7, §);
+ if (d) {
+ struct lvm_rec *p = (struct lvm_rec *)d;
+ u16 lvm_version = be16_to_cpu(p->version);
+ char tmp[64];
+
+ if (lvm_version == 1) {
+ int pp_size_log2 = be16_to_cpu(p->pp_size);
+
+ pp_bytes_size = 1 << pp_size_log2;
+ pp_blocks_size = pp_bytes_size / 512;
+ snprintf(tmp, sizeof(tmp),
+ " AIX LVM header version %u found\n",
+ lvm_version);
+ vgda_len = be32_to_cpu(p->vgda_len);
+ vgda_sector = be32_to_cpu(p->vgda_psn[0]);
+ } else {
+ snprintf(tmp, sizeof(tmp),
+ " unsupported AIX LVM version %d found\n",
+ lvm_version);
+ }
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ put_dev_sector(sect);
+ }
+ if (vgda_sector && (d = read_part_sector(state, vgda_sector, §))) {
+ struct vgda *p = (struct vgda *)d;
+
+ numlvs = be16_to_cpu(p->numlvs);
+ put_dev_sector(sect);
+ }
+ lvip = kzalloc(sizeof(struct lv_info) * state->limit, GFP_KERNEL);
+ if (!lvip)
+ return 0;
+ if (numlvs && (d = read_part_sector(state, vgda_sector + 1, §))) {
+ struct lvd *p = (struct lvd *)d;
+ int i;
+
+ n = alloc_lvn(state, vgda_sector + vgda_len - 33);
+ if (n) {
+ int foundlvs = 0;
+
+ for (i = 0; foundlvs < numlvs && i < state->limit; i += 1) {
+ lvip[i].pps_per_lv = be16_to_cpu(p[i].num_lps);
+ if (lvip[i].pps_per_lv)
+ foundlvs += 1;
+ }
+ }
+ put_dev_sector(sect);
+ }
+ pvd = alloc_pvd(state, vgda_sector + 17);
+ if (pvd) {
+ int numpps = be16_to_cpu(pvd->pp_count);
+ int psn_part1 = be32_to_cpu(pvd->psn_part1);
+ int i;
+ int cur_lv_ix = -1;
+ int next_lp_ix = 1;
+ int lp_ix;
+
+ for (i = 0; i < numpps; i += 1) {
+ struct ppe *p = pvd->ppe + i;
+ unsigned int lv_ix;
+
+ lp_ix = be16_to_cpu(p->lp_ix);
+ if (!lp_ix) {
+ next_lp_ix = 1;
+ continue;
+ }
+ lv_ix = be16_to_cpu(p->lv_ix) - 1;
+ if (lv_ix > state->limit) {
+ cur_lv_ix = -1;
+ continue;
+ }
+ lvip[lv_ix].pps_found += 1;
+ if (lp_ix == 1) {
+ cur_lv_ix = lv_ix;
+ next_lp_ix = 1;
+ } else if (lv_ix != cur_lv_ix || lp_ix != next_lp_ix) {
+ next_lp_ix = 1;
+ continue;
+ }
+ if (lp_ix == lvip[lv_ix].pps_per_lv) {
+ char tmp[70];
+
+ put_partition(state, lv_ix + 1,
+ (i + 1 - lp_ix) * pp_blocks_size + psn_part1,
+ lvip[lv_ix].pps_per_lv * pp_blocks_size);
+ snprintf(tmp, sizeof(tmp), " <%s>\n", n[lv_ix].name);
+ strlcat(state->pp_buf, tmp, PAGE_SIZE);
+ lvip[lv_ix].lv_is_contiguous = 1;
+ ret = 1;
+ next_lp_ix = 1;
+ } else
+ next_lp_ix += 1;
+ }
+ for (i = 0; i < state->limit; i += 1)
+ if (lvip[i].pps_found && !lvip[i].lv_is_contiguous)
+ printk("partition %s (%u pp's found) is not contiguous\n",
+ n[i].name, lvip[i].pps_found);
+ kfree(pvd);
+ }
+ if (n)
+ kfree(n);
+ kfree(lvip);
+ return ret;
+}
diff --git a/block/partitions/aix.h b/block/partitions/aix.h
new file mode 100644
index 0000000..e0c66a9
--- /dev/null
+++ b/block/partitions/aix.h
@@ -0,0 +1 @@
+extern int aix_partition(struct parsed_partitions *state);
--
1.7.1
--
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