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Merge find_fat_free() and extend() -- they were almost identical.

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Have a simplified clause for f_cluster == FREE.
Set f_cluster = FREE in shrink_file if the file is set to 0 bytes; in
that case we should set the current cluster to FREE even if it is
currently a LONG_LAST_CLUSTER.


git-svn-id: https://svn.code.sf.net/p/freedos/svn/kernel/trunk@818 6ac86273-5f31-0410-b378-82cca8765d1b
This commit is contained in:
Bart Oldeman 2004-03-23 00:45:24 +00:00
parent ce290a033f
commit 05cd65a193
1 changed files with 18 additions and 40 deletions
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58
kernel/fatfs.c
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@ -48,7 +48,6 @@ STATIC int is_same_file(f_node_ptr fnp1, f_node_ptr fnp2);
/* /// Added - Ron Cemer */
STATIC void copy_file_changes(f_node_ptr src, f_node_ptr dst);
BOOL find_free(f_node_ptr);
CLUSTER find_fat_free(f_node_ptr);
VOID wipe_out(f_node_ptr);
CLUSTER extend(f_node_ptr);
COUNT extend_dir(f_node_ptr);
@ -1227,9 +1226,6 @@ STATIC CLUSTER extend(f_node_ptr fnp)
{
CLUSTER free_fat;
#ifdef DISPLAY_GETBLOCK
printf("extend\n");
#endif
/* get an empty cluster, so that we use it to extend the file. */
free_fat = find_fat_free(fnp);
@ -1240,7 +1236,10 @@ STATIC CLUSTER extend(f_node_ptr fnp)
/* Now that we've found a free FAT entry, mark it as the last */
/* entry and save. */
link_fat(fnp->f_dpb, fnp->f_cluster, free_fat);
if (fnp->f_cluster == FREE)
setdstart(fnp->f_dpb, &fnp->f_dir, free_fat);
else
link_fat(fnp->f_dpb, fnp->f_cluster, free_fat);
link_fat(fnp->f_dpb, free_fat, LONG_LAST_CLUSTER);
/* Mark the directory so that the entry is updated */
@ -1296,31 +1295,6 @@ STATIC COUNT extend_dir(f_node_ptr fnp)
}
/* JPP: finds the next free cluster in the FAT */
STATIC CLUSTER first_fat(f_node_ptr fnp)
{
CLUSTER free_fat;
/* get an empty cluster, so that we make it into a file. */
free_fat = find_fat_free(fnp);
/* No empty clusters, disk is FULL! Translate into a useful */
/* error message. */
if (free_fat == LONG_LAST_CLUSTER)
return free_fat;
/* Now that we've found a free FAT entry, mark it as the last */
/* entry and save it. */
/* BUG!! this caused wrong allocation, if file was created,
then seeked, then written */
setdstart(fnp->f_dpb, &fnp->f_dir, free_fat);
link_fat(fnp->f_dpb, free_fat, LONG_LAST_CLUSTER);
/* Mark the directory so that the entry is updated */
fnp->f_flags.f_dmod = TRUE;
return free_fat;
}
/* Description.
* Finds the cluster which contains byte at the fnp->f_offset offset and
* stores its number to the fnp->f_cluster. The search begins from the start of
@ -1350,12 +1324,18 @@ COUNT map_cluster(REG f_node_ptr fnp, COUNT mode)
fnp->f_offset - fnp->f_cluster_offset);
#endif
/* If someone did a seek, but no writes have occured, we will */
/* need to initialize the fnode. */
if ((mode == XFR_WRITE) && checkdstart(fnp->f_dpb, &fnp->f_dir, FREE))
if (fnp->f_cluster == FREE)
{
/* If this is a read but the file still has zero bytes return */
/* immediately.... */
if (mode == XFR_READ)
return DE_SEEK;
/* If someone did a seek, but no writes have occured, we will */
/* need to initialize the fnode. */
/* (mode == XFR_WRITE) */
/* If there are no more free fat entries, then we are full! */
cluster = first_fat(fnp);
cluster = extend(fnp);
if (cluster == LONG_LAST_CLUSTER)
{
return DE_HNDLDSKFULL;
@ -1363,11 +1343,6 @@ COUNT map_cluster(REG f_node_ptr fnp, COUNT mode)
fnp->f_cluster = cluster;
}
/* If this is a read but the file still has zero bytes return */
/* immediately.... */
if ((mode == XFR_READ) && (fnp->f_cluster == FREE))
return DE_SEEK;
relcluster = (CLUSTER)((fnp->f_offset / fnp->f_dpb->dpb_secsize) >>
fnp->f_dpb->dpb_shftcnt);
if (relcluster < fnp->f_cluster_offset)
@ -2212,7 +2187,7 @@ STATIC VOID shrink_file(f_node_ptr fnp)
next = next_cluster(dpbp, st);
if (next == 1 || next == LONG_LAST_CLUSTER) /* error last cluster found */
if (next == 1) /* error */
goto done;
/* Loop from start until either a FREE entry is */
@ -2222,11 +2197,14 @@ STATIC VOID shrink_file(f_node_ptr fnp)
if (fnp->f_dir.dir_size == 0)
{
fnp->f_cluster = FREE;
setdstart(dpbp, &fnp->f_dir, FREE);
link_fat(dpbp, st, FREE);
}
else
{
if (next == LONG_LAST_CLUSTER) /* nothing to do */
goto done;
link_fat(dpbp, st, LONG_LAST_CLUSTER);
}