Changes in uspace/srv/fs/mfs/mfs_rw.c [7a46bfe:e895352] in mainline

File:

• uspace/srv/fs/mfs/mfs_rw.c (modified) (17 diffs)

uspace/srv/fs/mfs/mfs_rw.c

@@ -31 +31 @@
  */
 
+#include <align.h>
 #include "mfs.h"
 
 static int
 rw_map_ondisk(uint32_t *b, const struct mfs_node *mnode, int rblock,
-              bool write_mode, uint32_t w_block);
+    bool write_mode, uint32_t w_block);
 
 static int
@@ -53 +54 @@
  *bytes, this function returns the on-disk block
  *relative to that position.
- *Returns zero if the block does not exist.
+ *
+ * @param b     Pointer to a 32bit number where the block number will be stored
+ * @param mnode Pointer to a generic MINIX inode in memory.
+ * @param pos   Position in file.
+ *
+ * @return      EOK on success or a negative error code.
  */
 int
@@ -62 +68 @@
         const int block_size = sbi->block_size;
 
-        /*Compute relative block number in file*/
+        /* Compute relative block number in file */
         int rblock = pos / block_size;
 
-        if (mnode->ino_i->i_size < pos) {
-                /*Trying to read beyond the end of file*/
+        if (ROUND_UP(mnode->ino_i->i_size, sbi->block_size) < pos) {
+                /* Trying to read beyond the end of file */
                 r = EOK;
                 *b = 0;
@@ -79 +85 @@
 int
 mfs_write_map(struct mfs_node *mnode, const uint32_t pos, uint32_t new_zone,
-          uint32_t *old_zone)
+    uint32_t *old_zone)
 {
         const struct mfs_sb_info *sbi = mnode->instance->sbi;
 
         if (pos >= sbi->max_file_size) {
-                /*Can't write beyond the maximum file size*/
+                /* Can't write beyond the maximum file size */
                 return EINVAL;
         }
 
-        /*Compute the relative block number in file*/
+        /* Compute the relative block number in file */
         int rblock = pos / sbi->block_size;
 
@@ -96 +102 @@
 static int
 rw_map_ondisk(uint32_t *b, const struct mfs_node *mnode, int rblock,
-              bool write_mode, uint32_t w_block)
+    bool write_mode, uint32_t w_block)
 {
         int r, nr_direct;
@@ -117 +123 @@
         }
 
-        /*Check if the wanted block is in the direct zones*/
+        /* Check if the wanted block is in the direct zones */
         if (rblock < nr_direct) {
                 *b = ino_i->i_dzone[rblock];
@@ -130 +136 @@
 
         if (rblock < ptrs_per_block) {
-                /*The wanted block is in the single indirect zone chain*/
+                /* The wanted block is in the single indirect zone chain */
                 if (ino_i->i_izone[0] == 0) {
                         if (write_mode && !deleting) {
@@ -141 +147 @@
                                 ino_i->dirty = true;
                         } else {
-                                /*Sparse block*/
+                                /* Sparse block */
                                 *b = 0;
                                 return EOK;
@@ -162 +168 @@
         rblock -= ptrs_per_block;
 
-        /*The wanted block is in the double indirect zone chain*/
-
-        /*read the first indirect zone of the chain*/
+        /* The wanted block is in the double indirect zone chain */
+
+        /* Read the first indirect zone of the chain */
         if (ino_i->i_izone[1] == 0) {
                 if (write_mode && !deleting) {
@@ -175 +181 @@
                         ino_i->dirty = true;
                 } else {
-                        /*Sparse block*/
+                        /* Sparse block */
                         *b = 0;
                         return EOK;
@@ -186 +192 @@
 
         /*
-         *Compute the position of the second indirect
-         *zone pointer in the chain.
+         * Compute the position of the second indirect
+         * zone pointer in the chain.
          */
         uint32_t ind2_off = rblock / ptrs_per_block;
 
-        /*read the second indirect zone of the chain*/
+        /* read the second indirect zone of the chain */
         if (ind_zone[ind2_off] == 0) {
                 if (write_mode && !deleting) {
@@ -202 +208 @@
                         write_ind_zone(inst, ino_i->i_izone[1], ind_zone);
                 } else {
-                        /*Sparse block*/
+                        /* Sparse block */
                         r = EOK;
                         *b = 0;
@@ -227 +233 @@
 }
 
-/*Free unused indirect zones*/
+/**Free unused indirect zones from a MINIX inode according to its new size.
+ *
+ * @param mnode         Pointer to a generic MINIX inode in memory.
+ * @param new_size      The new size of the inode.
+ *
+ * @return              EOK on success or a negative error code.
+ */
 int
 mfs_prune_ind_zones(struct mfs_node *mnode, size_t new_size)
@@ -239 +251 @@
         mfs_version_t fs_version = sbi->fs_version;
         
+        assert(new_size <= ino_i->i_size);
+
         if (fs_version == MFS_VERSION_V1) {
                 nr_direct = V1_NR_DIRECT_ZONES;
@@ -250 +264 @@
 
         if (rblock < nr_direct) {
-                /*free the single indirect zone*/
+                /* Free the single indirect zone */
                 if (ino_i->i_izone[0]) {
                         r = mfs_free_zone(inst, ino_i->i_izone[0]);
@@ -268 +282 @@
                 ++fzone_to_free;
 
-        /*free the entire double indirect zone*/
+        /* Free the entire double indirect zone */
         uint32_t *dbl_zone;
 
         if (ino_i->i_izone[1] == 0) {
-                /*Nothing to be done*/
+                /* Nothing to be done */
                 return EOK;
         }
@@ -336 +350 @@
         block_t *b;
         const int max_ind_zone_ptrs = (MFS_MAX_BLOCKSIZE / sizeof(uint16_t)) *
-                                      sizeof(uint32_t);
+            sizeof(uint32_t);
 
         *ind_zone = malloc(max_ind_zone_ptrs);