[syslinux:pathbased] fs: fix cwd setting for FAT/iso9660/extfs

[syslinux-bot for H. Peter Anvin]

Commit-ID:  3db9073fdd604c253ab0ea0ce83373dc89f633f3
Gitweb:     http://syslinux.zytor.com/commit/3db9073fdd604c253ab0ea0ce83373dc89f633f3
Author:     H. Peter Anvin <hpa at zytor.com>
AuthorDate: Wed, 10 Feb 2010 16:21:55 -0800
Committer:  H. Peter Anvin <hpa at zytor.com>
CommitDate: Wed, 10 Feb 2010 16:21:55 -0800

fs: fix cwd setting for FAT/iso9660/extfs

Fix the cwd setting for FAT, iso9660 and ext*fs.
In particular:

When FS_THISIND is set in the filesystem flags, only memoize the
parent directory iff we are currently doing a config file walk.  Use
this feature for ext*fs as well, this makes the pathbased branch fully
featured.

Signed-off-by: H. Peter Anvin <hpa at zytor.com>


---
 core/fs.c           |   16 +++++++++++++---
 core/fs/ext2/ext2.c |   17 ++++-------------
 core/fs/fat/fat.c   |    1 -
 core/include/fs.h   |   11 ++---------
 4 files changed, 19 insertions(+), 26 deletions(-)

diff --git a/core/fs.c b/core/fs.c
index 0eac0f2..ecd5257 100644
--- a/core/fs.c
+++ b/core/fs.c
@@ -5,14 +5,19 @@
 #include <cache.h>
 
 /* The currently mounted filesystem */
-struct fs_info *this_fs = NULL;
+struct fs_info *this_fs = NULL;		/* Root filesystem */
 static struct fs_info fs;
-struct inode *this_inode = NULL;
+static struct inode *this_inode = NULL;	/* Current working directory */
 
 /* Actual file structures (we don't have malloc yet...) */
 struct file files[MAX_OPEN];
 
 /*
+ * Set to FS_THISIND during the execution of load_config.
+ */
+enum fs_flags is_load_config = 0;
+
+/*
  * Get a new inode structure
  */
 struct inode *alloc_inode(struct fs_info *fs, uint32_t ino, size_t data)
@@ -72,7 +77,10 @@ inline struct file *handle_to_file(uint16_t handle)
 void load_config(void)
 {
     int err;
+
+    is_load_config = FS_THISIND;
     err = this_fs->fs_ops->load_config();
+    is_load_config = 0;
 
 #if 0
     printf("Loading config file %s\n", err ? "failed" : "successed");
@@ -195,7 +203,7 @@ void searchdir(com32sys_t *regs)
 	    /* 
 	     * For the relative path searching used in FAT and ISO fs.
 	     */
-	    if ((this_fs->fs_ops->fs_flags & FS_THISIND) &&
+	    if ((this_fs->fs_ops->fs_flags & is_load_config) &&
 		(this_inode != parent)){
 		if (this_inode)
 		    free_inode(this_inode);
@@ -297,4 +305,6 @@ void fs_init(com32sys_t *regs)
 
     if (fs.fs_ops->iget_current)
 	this_inode = fs.fs_ops->iget_current(&fs);
+    else
+	this_inode = fs.fs_ops->iget_root(&fs); /* Will be set later */
 }
diff --git a/core/fs/ext2/ext2.c b/core/fs/ext2/ext2.c
index fbb57be..9cdbb3b 100644
--- a/core/fs/ext2/ext2.c
+++ b/core/fs/ext2/ext2.c
@@ -303,13 +303,6 @@ static struct inode *ext2_iget_root(struct fs_info *fs)
     return ext2_iget_by_inr(fs, EXT2_ROOT_INO);
 }
 
-static struct inode *ext2_iget_current(struct fs_info *fs)
-{
-    static int CurrentDir = 2;
-    
-    return ext2_iget_by_inr(fs, CurrentDir);
-}
-
 static struct inode *ext2_iget(char *dname, struct inode *parent)
 {
         struct ext2_dir_entry *de;
@@ -323,7 +316,7 @@ static struct inode *ext2_iget(char *dname, struct inode *parent)
 }
 
 
-static char * ext2_follow_symlink(struct inode *inode, const char *name_left)
+static char *ext2_follow_symlink(struct inode *inode, const char *name_left)
 {
     struct fs_info *fs = inode->fs;
     int sec_per_block = 1 << (fs->block_shift - fs->sector_shift);
@@ -399,10 +392,8 @@ static int ext2_load_config(void)
     char *config_name = "extlinux.conf";
     com32sys_t regs;
     
-    strcpy(ConfigName, config_name);
-    *(uint32_t *)CurrentDirName = 0x00002f2e;  
-    
     memset(&regs, 0, sizeof regs);
+    snprintf(ConfigName, FILENAME_MAX, "%s/extlinux.conf", CurrentDirName);
     regs.edi.w[0] = OFFS_WRT(ConfigName, 0);
     call16(core_open, &regs, &regs);
 
@@ -460,7 +451,7 @@ static int ext2_fs_init(struct fs_info *fs)
 
 const struct fs_ops ext2_fs_ops = {
     .fs_name       = "ext2",
-    .fs_flags      = FS_USEMEM,
+    .fs_flags      = FS_THISIND | FS_USEMEM,
     .fs_init       = ext2_fs_init,
     .searchdir     = NULL,
     .getfssec      = ext2_getfssec,
@@ -469,7 +460,7 @@ const struct fs_ops ext2_fs_ops = {
     .unmangle_name = generic_unmangle_name,
     .load_config   = ext2_load_config,
     .iget_root     = ext2_iget_root,
-    .iget_current  = ext2_iget_current,
+    .iget_current  = NULL,
     .iget          = ext2_iget,
     .follow_symlink = ext2_follow_symlink,
     .readdir       = ext2_readdir
diff --git a/core/fs/fat/fat.c b/core/fs/fat/fat.c
index d723f28..c388dba 100644
--- a/core/fs/fat/fat.c
+++ b/core/fs/fat/fat.c
@@ -759,7 +759,6 @@ static int vfat_load_config(void)
     if (*CurrentDirName) { /* installed by extlinux not syslinux */
 	sprintf(ConfigName, "%s/extlinux.conf", CurrentDirName);
 	call16(core_open, &regs, &regs);
-	strcpy(ConfigName, "extlinux.conf");
 	return regs.eflags.l & EFLAGS_ZF;
     }
     /* installed by syslinux */
diff --git a/core/include/fs.h b/core/include/fs.h
index 394b2ae..2477e4e 100644
--- a/core/include/fs.h
+++ b/core/include/fs.h
@@ -40,13 +40,8 @@ struct dirent;                  /* Directory entry structure */
 struct file;
 enum fs_flags {
     FS_NODEV   = 1 << 0,
-    FS_USEMEM  = 1 << 1,         /* If we need a malloc routine, set it */
-
- /* 
-  * Update the this_inode pointer at each part of path searching. This 
-  * flag is just used for FAT and ISO fs for now.
-  */
-    FS_THISIND = 1 << 2,        
+    FS_USEMEM  = 1 << 1,        /* If we need a malloc routine, set it */
+    FS_THISIND = 1 << 2,        /* Set cwd based on config file location */
 };
 
 struct fs_ops {
@@ -91,8 +86,6 @@ struct inode {
     char         pvt[0]; /* Private filesystem data */
 };
 
-extern struct inode *this_inode;
-
 struct open_file_t;
 
 struct file {