Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6:
  fat: split fat_generic_ioctl
  FAT: add 'errors' mount option

Documentation/filesystems/vfat.txt

@@ -132,6 +132,11 @@ rodir	      -- FAT has the ATTR_RO (read-only) attribute. On Windows,
 		 If you want to use ATTR_RO as read-only flag even for
 		 the directory, set this option.
 
+errors=panic|continue|remount-ro
+	      -- specify FAT behavior on critical errors: panic, continue
+		 without doing anything or remount the partition in
+		 read-only mode (default behavior).
+
 <bool>: 0,1,yes,no,true,false
 
 TODO

fs/fat/cache.c

@@ -241,7 +241,7 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
 	while (*fclus < cluster) {
 		/* prevent the infinite loop of cluster chain */
 		if (*fclus > limit) {
-			fat_fs_panic(sb, "%s: detected the cluster chain loop"
+			fat_fs_error(sb, "%s: detected the cluster chain loop"
 				     " (i_pos %lld)", __func__,
 				     MSDOS_I(inode)->i_pos);
 			nr = -EIO;
@@ -252,7 +252,7 @@ int fat_get_cluster(struct inode *inode, int cluster, int *fclus, int *dclus)
 		if (nr < 0)
 			goto out;
 		else if (nr == FAT_ENT_FREE) {
-			fat_fs_panic(sb, "%s: invalid cluster chain"
+			fat_fs_error(sb, "%s: invalid cluster chain"
 				     " (i_pos %lld)", __func__,
 				     MSDOS_I(inode)->i_pos);
 			nr = -EIO;
@@ -285,7 +285,7 @@ static int fat_bmap_cluster(struct inode *inode, int cluster)
 	if (ret < 0)
 		return ret;
 	else if (ret == FAT_ENT_EOF) {
-		fat_fs_panic(sb, "%s: request beyond EOF (i_pos %lld)",
+		fat_fs_error(sb, "%s: request beyond EOF (i_pos %lld)",
 			     __func__, MSDOS_I(inode)->i_pos);
 		return -EIO;
 	}

fs/fat/dir.c

@@ -1334,7 +1334,7 @@ found:
 			goto error_remove;
 		}
 		if (dir->i_size & (sbi->cluster_size - 1)) {
-			fat_fs_panic(sb, "Odd directory size");
+			fat_fs_error(sb, "Odd directory size");
 			dir->i_size = (dir->i_size + sbi->cluster_size - 1)
 				& ~((loff_t)sbi->cluster_size - 1);
 		}

fs/fat/fat.h

@@ -17,6 +17,10 @@
 #define VFAT_SFN_CREATE_WIN95	0x0100 /* emulate win95 rule for create */
 #define VFAT_SFN_CREATE_WINNT	0x0200 /* emulate winnt rule for create */
 
+#define FAT_ERRORS_CONT		1      /* ignore error and continue */
+#define FAT_ERRORS_PANIC	2      /* panic on error */
+#define FAT_ERRORS_RO		3      /* remount r/o on error */
+
 struct fat_mount_options {
 	uid_t fs_uid;
 	gid_t fs_gid;
@@ -26,6 +30,7 @@ struct fat_mount_options {
 	char *iocharset;          /* Charset used for filename input/display */
 	unsigned short shortname; /* flags for shortname display/create rule */
 	unsigned char name_check; /* r = relaxed, n = normal, s = strict */
+	unsigned char errors;	  /* On error: continue, panic, remount-ro */
 	unsigned short allow_utime;/* permission for setting the [am]time */
 	unsigned quiet:1,         /* set = fake successful chmods and chowns */
 		 showexec:1,      /* set = only set x bit for com/exe/bat */
@@ -316,7 +321,7 @@ extern int fat_fill_super(struct super_block *sb, void *data, int silent,
 extern int fat_flush_inodes(struct super_block *sb, struct inode *i1,
 		            struct inode *i2);
 /* fat/misc.c */
-extern void fat_fs_panic(struct super_block *s, const char *fmt, ...)
+extern void fat_fs_error(struct super_block *s, const char *fmt, ...)
 	__attribute__ ((format (printf, 2, 3))) __cold;
 extern void fat_clusters_flush(struct super_block *sb);
 extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster);

fs/fat/fatent.c

@@ -348,7 +348,7 @@ int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry)
 
 	if (entry < FAT_START_ENT || sbi->max_cluster <= entry) {
 		fatent_brelse(fatent);
-		fat_fs_panic(sb, "invalid access to FAT (entry 0x%08x)", entry);
+		fat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", entry);
 		return -EIO;
 	}
 
@@ -560,7 +560,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
 			err = cluster;
 			goto error;
 		} else if (cluster == FAT_ENT_FREE) {
-			fat_fs_panic(sb, "%s: deleting FAT entry beyond EOF",
+			fat_fs_error(sb, "%s: deleting FAT entry beyond EOF",
 				     __func__);
 			err = -EIO;
 			goto error;

fs/fat/file.c

@@ -18,15 +18,8 @@
 #include <linux/security.h>
 #include "fat.h"
 
-int fat_generic_ioctl(struct inode *inode, struct file *filp,
-		      unsigned int cmd, unsigned long arg)
+static int fat_ioctl_get_attributes(struct inode *inode, u32 __user *user_attr)
 {
-	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
-	u32 __user *user_attr = (u32 __user *)arg;
-
-	switch (cmd) {
-	case FAT_IOCTL_GET_ATTRIBUTES:
-	{
 	u32 attr;
 
 	mutex_lock(&inode->i_mutex);
@@ -34,22 +27,25 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 	mutex_unlock(&inode->i_mutex);
 
 	return put_user(attr, user_attr);
-	}
-	case FAT_IOCTL_SET_ATTRIBUTES:
-	{
+}
+
+static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
+	int is_dir = S_ISDIR(inode->i_mode);
 	u32 attr, oldattr;
-		int err, is_dir = S_ISDIR(inode->i_mode);
 	struct iattr ia;
+	int err;
 
 	err = get_user(attr, user_attr);
 	if (err)
-			return err;
+		goto out;
 
 	mutex_lock(&inode->i_mutex);
-
-		err = mnt_want_write(filp->f_path.mnt);
+	err = mnt_want_write(file->f_path.mnt);
 	if (err)
-			goto up_no_drop_write;
+		goto out_unlock_inode;
 
 	/*
 	 * ATTR_VOLUME and ATTR_DIR cannot be changed; this also
@@ -76,16 +72,14 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 	/* The root directory has no attributes */
 	if (inode->i_ino == MSDOS_ROOT_INO && attr != ATTR_DIR) {
 		err = -EINVAL;
-			goto up;
+		goto out_drop_write;
 	}
 
-		if (sbi->options.sys_immutable) {
-			if ((attr | oldattr) & ATTR_SYS) {
-				if (!capable(CAP_LINUX_IMMUTABLE)) {
+	if (sbi->options.sys_immutable &&
+	    ((attr | oldattr) & ATTR_SYS) &&
+	    !capable(CAP_LINUX_IMMUTABLE)) {
 		err = -EPERM;
-					goto up;
-				}
-			}
+		goto out_drop_write;
 	}
 
 	/*
@@ -93,16 +87,16 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 	 * out the RO attribute for checking by the security
 	 * module, just because it maps to a file mode.
 	 */
-		err = security_inode_setattr(filp->f_path.dentry, &ia);
+	err = security_inode_setattr(file->f_path.dentry, &ia);
 	if (err)
-			goto up;
+		goto out_drop_write;
 
 	/* This MUST be done before doing anything irreversible... */
-		err = fat_setattr(filp->f_path.dentry, &ia);
+	err = fat_setattr(file->f_path.dentry, &ia);
 	if (err)
-			goto up;
+		goto out_drop_write;
 
-		fsnotify_change(filp->f_path.dentry, ia.ia_valid);
+	fsnotify_change(file->f_path.dentry, ia.ia_valid);
 	if (sbi->options.sys_immutable) {
 		if (attr & ATTR_SYS)
 			inode->i_flags |= S_IMMUTABLE;
@@ -112,12 +106,24 @@ int fat_generic_ioctl(struct inode *inode, struct file *filp,
 
 	fat_save_attrs(inode, attr);
 	mark_inode_dirty(inode);
-up:
-		mnt_drop_write(filp->f_path.mnt);
-up_no_drop_write:
+out_drop_write:
+	mnt_drop_write(file->f_path.mnt);
+out_unlock_inode:
 	mutex_unlock(&inode->i_mutex);
+out:
 	return err;
-	}
+}
+
+int fat_generic_ioctl(struct inode *inode, struct file *filp,
+		      unsigned int cmd, unsigned long arg)
+{
+	u32 __user *user_attr = (u32 __user *)arg;
+
+	switch (cmd) {
+	case FAT_IOCTL_GET_ATTRIBUTES:
+		return fat_ioctl_get_attributes(inode, user_attr);
+	case FAT_IOCTL_SET_ATTRIBUTES:
+		return fat_ioctl_set_attributes(filp, user_attr);
 	default:
 		return -ENOTTY;	/* Inappropriate ioctl for device */
 	}
@@ -225,7 +231,7 @@ static int fat_free(struct inode *inode, int skip)
 			fatent_brelse(&fatent);
 			return 0;
 		} else if (ret == FAT_ENT_FREE) {
-			fat_fs_panic(sb,
+			fat_fs_error(sb,
 				     "%s: invalid cluster chain (i_pos %lld)",
 				     __func__, MSDOS_I(inode)->i_pos);
 			ret = -EIO;

fs/fat/inode.c

@@ -76,7 +76,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
 		return 0;
 
 	if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
-		fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
+		fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
 			MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
 		return -EIO;
 	}
@@ -856,6 +856,12 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
 		seq_puts(m, ",flush");
 	if (opts->tz_utc)
 		seq_puts(m, ",tz=UTC");
+	if (opts->errors == FAT_ERRORS_CONT)
+		seq_puts(m, ",errors=continue");
+	else if (opts->errors == FAT_ERRORS_PANIC)
+		seq_puts(m, ",errors=panic");
+	else
+		seq_puts(m, ",errors=remount-ro");
 
 	return 0;
 }
@@ -868,7 +874,8 @@ enum {
 	Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
 	Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
 	Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
-	Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err,
+	Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
+	Opt_err_panic, Opt_err_ro, Opt_err,
 };
 
 static const match_table_t fat_tokens = {
@@ -891,6 +898,11 @@ static const match_table_t fat_tokens = {
 	{Opt_showexec, "showexec"},
 	{Opt_debug, "debug"},
 	{Opt_immutable, "sys_immutable"},
+	{Opt_flush, "flush"},
+	{Opt_tz_utc, "tz=UTC"},
+	{Opt_err_cont, "errors=continue"},
+	{Opt_err_panic, "errors=panic"},
+	{Opt_err_ro, "errors=remount-ro"},
 	{Opt_obsolate, "conv=binary"},
 	{Opt_obsolate, "conv=text"},
 	{Opt_obsolate, "conv=auto"},
@@ -902,8 +914,6 @@ static const match_table_t fat_tokens = {
 	{Opt_obsolate, "cvf_format=%20s"},
 	{Opt_obsolate, "cvf_options=%100s"},
 	{Opt_obsolate, "posix"},
-	{Opt_flush, "flush"},
-	{Opt_tz_utc, "tz=UTC"},
 	{Opt_err, NULL},
 };
 static const match_table_t msdos_tokens = {
@@ -973,6 +983,7 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 	opts->numtail = 1;
 	opts->usefree = opts->nocase = 0;
 	opts->tz_utc = 0;
+	opts->errors = FAT_ERRORS_RO;
 	*debug = 0;
 
 	if (!options)
@@ -1065,6 +1076,15 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug,
 		case Opt_tz_utc:
 			opts->tz_utc = 1;
 			break;
+		case Opt_err_cont:
+			opts->errors = FAT_ERRORS_CONT;
+			break;
+		case Opt_err_panic:
+			opts->errors = FAT_ERRORS_PANIC;
+			break;
+		case Opt_err_ro:
+			opts->errors = FAT_ERRORS_RO;
+			break;
 
 		/* msdos specific */
 		case Opt_dots:

fs/fat/misc.c

@@ -12,14 +12,19 @@
 #include "fat.h"
 
 /*
- * fat_fs_panic reports a severe file system problem and sets the file system
- * read-only. The file system can be made writable again by remounting it.
+ * fat_fs_error reports a file system problem that might indicate fa data
+ * corruption/inconsistency. Depending on 'errors' mount option the
+ * panic() is called, or error message is printed FAT and nothing is done,
+ * or filesystem is remounted read-only (default behavior).
+ * In case the file system is remounted read-only, it can be made writable
+ * again by remounting it.
  */
-void fat_fs_panic(struct super_block *s, const char *fmt, ...)
+void fat_fs_error(struct super_block *s, const char *fmt, ...)
 {
+	struct fat_mount_options *opts = &MSDOS_SB(s)->options;
 	va_list args;
 
-	printk(KERN_ERR "FAT: Filesystem panic (dev %s)\n", s->s_id);
+	printk(KERN_ERR "FAT: Filesystem error (dev %s)\n", s->s_id);
 
 	printk(KERN_ERR "    ");
 	va_start(args, fmt);
@@ -27,13 +32,14 @@ void fat_fs_panic(struct super_block *s, const char *fmt, ...)
 	va_end(args);
 	printk("\n");
 
-	if (!(s->s_flags & MS_RDONLY)) {
+	if (opts->errors == FAT_ERRORS_PANIC)
+		panic("    FAT fs panic from previous error\n");
+	else if (opts->errors == FAT_ERRORS_RO && !(s->s_flags & MS_RDONLY)) {
 		s->s_flags |= MS_RDONLY;
 		printk(KERN_ERR "    File system has been set read-only\n");
 	}
 }
-
-EXPORT_SYMBOL_GPL(fat_fs_panic);
+EXPORT_SYMBOL_GPL(fat_fs_error);
 
 /* Flushes the number of free clusters on FAT32 */
 /* XXX: Need to write one per FSINFO block.  Currently only writes 1 */
@@ -124,7 +130,7 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
 			mark_inode_dirty(inode);
 	}
 	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
-		fat_fs_panic(sb, "clusters badly computed (%d != %llu)",
+		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
 			     new_fclus,
 			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
 		fat_cache_inval_inode(inode);

fs/fat/namei_msdos.c

@@ -608,7 +608,7 @@ error_inode:
 		sinfo.bh = NULL;
 	}
 	if (corrupt < 0) {
-		fat_fs_panic(new_dir->i_sb,
+		fat_fs_error(new_dir->i_sb,
 			     "%s: Filesystem corrupted (i_pos %lld)",
 			     __func__, sinfo.i_pos);
 	}

fs/fat/namei_vfat.c

@@ -1030,7 +1030,7 @@ error_inode:
 		sinfo.bh = NULL;
 	}
 	if (corrupt < 0) {
-		fat_fs_panic(new_dir->i_sb,
+		fat_fs_error(new_dir->i_sb,
 			     "%s: Filesystem corrupted (i_pos %lld)",
 			     __func__, sinfo.i_pos);
 	}