mtd: prepare partition add and del functions for ioctl requests
Roman Tereshonkov [Fri, 17 Sep 2010 10:31:41 +0000 (13:31 +0300)]
mtd_is_master, mtd_add_partition and mtd_del_partition functions
are added to give the possibility of partition manipulation
by ioctl request.

The old partition add function is modified to fit the dynamic
allocation.

Signed-off-by: Roman Tereshonkov <roman.tereshonkov@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/mtdpart.c
include/linux/mtd/partitions.h

index dc65585..79e3689 100644 (file)
 #include <linux/kmod.h>
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
+#include <linux/err.h>
 
 /* Our partition linked list */
 static LIST_HEAD(mtd_partitions);
+static DEFINE_MUTEX(mtd_partitions_mutex);
 
 /* Our partition node structure */
 struct mtd_part {
@@ -326,6 +328,12 @@ static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
        return res;
 }
 
+static inline void free_partition(struct mtd_part *p)
+{
+       kfree(p->mtd.name);
+       kfree(p);
+}
+
 /*
  * This function unregisters and destroy all slave MTD objects which are
  * attached to the given master MTD object.
@@ -334,33 +342,42 @@ static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
 int del_mtd_partitions(struct mtd_info *master)
 {
        struct mtd_part *slave, *next;
+       int ret, err = 0;
 
+       mutex_lock(&mtd_partitions_mutex);
        list_for_each_entry_safe(slave, next, &mtd_partitions, list)
                if (slave->master == master) {
+                       ret = del_mtd_device(&slave->mtd);
+                       if (ret < 0) {
+                               err = ret;
+                               continue;
+                       }
                        list_del(&slave->list);
-                       del_mtd_device(&slave->mtd);
-                       kfree(slave);
+                       free_partition(slave);
                }
+       mutex_unlock(&mtd_partitions_mutex);
 
-       return 0;
+       return err;
 }
 EXPORT_SYMBOL(del_mtd_partitions);
 
-static struct mtd_part *add_one_partition(struct mtd_info *master,
-               const struct mtd_partition *part, int partno,
-               uint64_t cur_offset)
+static struct mtd_part *allocate_partition(struct mtd_info *master,
+                       const struct mtd_partition *part, int partno,
+                       uint64_t cur_offset)
 {
        struct mtd_part *slave;
+       char *name;
 
        /* allocate the partition structure */
        slave = kzalloc(sizeof(*slave), GFP_KERNEL);
-       if (!slave) {
+       name = kstrdup(part->name, GFP_KERNEL);
+       if (!name || !slave) {
                printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
-                       master->name);
-               del_mtd_partitions(master);
-               return NULL;
+                      master->name);
+               kfree(name);
+               kfree(slave);
+               return ERR_PTR(-ENOMEM);
        }
-       list_add(&slave->list, &mtd_partitions);
 
        /* set up the MTD object for this partition */
        slave->mtd.type = master->type;
@@ -371,7 +388,7 @@ static struct mtd_part *add_one_partition(struct mtd_info *master,
        slave->mtd.oobavail = master->oobavail;
        slave->mtd.subpage_sft = master->subpage_sft;
 
-       slave->mtd.name = part->name;
+       slave->mtd.name = name;
        slave->mtd.owner = master->owner;
        slave->mtd.backing_dev_info = master->backing_dev_info;
 
@@ -518,12 +535,89 @@ static struct mtd_part *add_one_partition(struct mtd_info *master,
        }
 
 out_register:
-       /* register our partition */
-       add_mtd_device(&slave->mtd);
-
        return slave;
 }
 
+int mtd_add_partition(struct mtd_info *master, char *name,
+                     long long offset, long long length)
+{
+       struct mtd_partition part;
+       struct mtd_part *p, *new;
+       uint64_t start, end;
+       int ret = 0;
+
+       /* the direct offset is expected */
+       if (offset == MTDPART_OFS_APPEND ||
+           offset == MTDPART_OFS_NXTBLK)
+               return -EINVAL;
+
+       if (length == MTDPART_SIZ_FULL)
+               length = master->size - offset;
+
+       if (length <= 0)
+               return -EINVAL;
+
+       part.name = name;
+       part.size = length;
+       part.offset = offset;
+       part.mask_flags = 0;
+       part.ecclayout = NULL;
+
+       new = allocate_partition(master, &part, -1, offset);
+       if (IS_ERR(new))
+               return PTR_ERR(new);
+
+       start = offset;
+       end = offset + length;
+
+       mutex_lock(&mtd_partitions_mutex);
+       list_for_each_entry(p, &mtd_partitions, list)
+               if (p->master == master) {
+                       if ((start >= p->offset) &&
+                           (start < (p->offset + p->mtd.size)))
+                               goto err_inv;
+
+                       if ((end >= p->offset) &&
+                           (end < (p->offset + p->mtd.size)))
+                               goto err_inv;
+               }
+
+       list_add(&new->list, &mtd_partitions);
+       mutex_unlock(&mtd_partitions_mutex);
+
+       add_mtd_device(&new->mtd);
+
+       return ret;
+err_inv:
+       mutex_unlock(&mtd_partitions_mutex);
+       free_partition(new);
+       return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(mtd_add_partition);
+
+int mtd_del_partition(struct mtd_info *master, int partno)
+{
+       struct mtd_part *slave, *next;
+       int ret = -EINVAL;
+
+       mutex_lock(&mtd_partitions_mutex);
+       list_for_each_entry_safe(slave, next, &mtd_partitions, list)
+               if ((slave->master == master) &&
+                   (slave->mtd.index == partno)) {
+                       ret = del_mtd_device(&slave->mtd);
+                       if (ret < 0)
+                               break;
+
+                       list_del(&slave->list);
+                       free_partition(slave);
+                       break;
+               }
+       mutex_unlock(&mtd_partitions_mutex);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(mtd_del_partition);
+
 /*
  * This function, given a master MTD object and a partition table, creates
  * and registers slave MTD objects which are bound to the master according to
@@ -544,9 +638,16 @@ int add_mtd_partitions(struct mtd_info *master,
        printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
 
        for (i = 0; i < nbparts; i++) {
-               slave = add_one_partition(master, parts + i, i, cur_offset);
-               if (!slave)
-                       return -ENOMEM;
+               slave = allocate_partition(master, parts + i, i, cur_offset);
+               if (IS_ERR(slave))
+                       return PTR_ERR(slave);
+
+               mutex_lock(&mtd_partitions_mutex);
+               list_add(&slave->list, &mtd_partitions);
+               mutex_unlock(&mtd_partitions_mutex);
+
+               add_mtd_device(&slave->mtd);
+
                cur_offset = slave->offset + slave->mtd.size;
        }
 
@@ -618,3 +719,20 @@ int parse_mtd_partitions(struct mtd_info *master, const char **types,
        return ret;
 }
 EXPORT_SYMBOL_GPL(parse_mtd_partitions);
+
+int mtd_is_master(struct mtd_info *mtd)
+{
+       struct mtd_part *part;
+       int nopart = 0;
+
+       mutex_lock(&mtd_partitions_mutex);
+       list_for_each_entry(part, &mtd_partitions, list)
+               if (&part->mtd == mtd) {
+                       nopart = 1;
+                       break;
+               }
+       mutex_unlock(&mtd_partitions_mutex);
+
+       return nopart;
+}
+EXPORT_SYMBOL_GPL(mtd_is_master);
index 930c8ac..2b54316 100644 (file)
@@ -89,4 +89,9 @@ static inline int mtd_has_cmdlinepart(void) { return 1; }
 static inline int mtd_has_cmdlinepart(void) { return 0; }
 #endif
 
+int mtd_is_master(struct mtd_info *mtd);
+int mtd_add_partition(struct mtd_info *master, char *name,
+                     long long offset, long long length);
+int mtd_del_partition(struct mtd_info *master, int partno);
+
 #endif