Commit dfc209c0 authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Linus Torvalds
Browse files

fat: Fix ATTR_RO for directory 

FAT has the ATTR_RO (read-only) attribute. But on Windows, the ATTR_RO
of the directory will be just ignored actually, and is used by only
applications as flag. E.g. it's setted for the customized folder by
Explorer.

http://msdn2.microsoft.com/en-us/library/aa969337.aspx



This adds "rodir" option. If user specified it, ATTR_RO is used as
read-only flag even if it's the directory. Otherwise, inode->i_mode
is not used to hold ATTR_RO (i.e. fat_mode_can_save_ro() returns 0).

Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9183482f

Documentation/filesystems/vfat.txt

+8 −0
Original line number Diff line number Diff line
@@ -124,6 +124,14 @@ sys_immutable -- If set, ATTR_SYS attribute on FAT is handled as 
flush         -- If set, the filesystem will try to flush to disk more

		 early than normal. Not set by default.



rodir	      -- FAT has the ATTR_RO (read-only) attribute. But on Windows,

		 the ATTR_RO of the directory will be just ignored actually,

		 and is used by only applications as flag. E.g. it's setted

		 for the customized folder.



		 If you want to use ATTR_RO as read-only flag even for

		 the directory, set this option.



<bool>: 0,1,yes,no,true,false



TODO

fs/fat/fat.h

+10 −4
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ struct fat_mount_options { 
		 flush:1,	  /* write things quickly */

		 nocase:1,	  /* Does this need case conversion? 0=need case conversion*/

		 usefree:1,	  /* Use free_clusters for FAT32 */

		 tz_utc:1;	  /* Filesystem timestamps are in UTC */

		 tz_utc:1,	  /* Filesystem timestamps are in UTC */

		 rodir:1;	  /* allow ATTR_RO for directory */

};



#define FAT_HASH_BITS	8
@@ -120,15 +121,20 @@ static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) 
/*

 * If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to

 * save ATTR_RO instead of ->i_mode.

 *

 * If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only

 * bit, it's just used as flag for app.

 */

static inline int fat_mode_can_hold_ro(struct inode *inode)

{

	struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);

	mode_t mask;



	if (S_ISDIR(inode->i_mode))

	if (S_ISDIR(inode->i_mode)) {

		if (!sbi->options.rodir)

			return 0;

		mask = ~sbi->options.fs_dmask;

	else

	} else

		mask = ~sbi->options.fs_fmask;



	if (!(mask & S_IWUGO))
@@ -140,7 +146,7 @@ static inline int fat_mode_can_hold_ro(struct inode *inode) 
static inline mode_t fat_make_mode(struct msdos_sb_info *sbi,

				   u8 attrs, mode_t mode)

{

	if (attrs & ATTR_RO)

	if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir))

		mode &= ~S_IWUGO;



	if (attrs & ATTR_DIR)

fs/fat/file.c

+12 −4
Original line number Diff line number Diff line
@@ -282,11 +282,18 @@ static int fat_sanitize_mode(const struct msdos_sb_info *sbi, 
	/*

	 * Of the r and x bits, all (subject to umask) must be present. Of the

	 * w bits, either all (subject to umask) or none must be present.

	 *

	 * If fat_mode_can_hold_ro(inode) is false, can't change w bits.

	 */

	if ((perm & (S_IRUGO | S_IXUGO)) != (inode->i_mode & (S_IRUGO|S_IXUGO)))

		return -EPERM;

	if (fat_mode_can_hold_ro(inode)) {

		if ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))

			return -EPERM;

	} else {

		if ((perm & S_IWUGO) != (S_IWUGO & ~mask))

			return -EPERM;

	}



	*mode_ptr &= S_IFMT | perm;
@@ -316,8 +323,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) 
{

	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);

	struct inode *inode = dentry->d_inode;

	int error = 0;

	unsigned int ia_valid;

	int error;



	/*

	 * Expand the file. Since inode_setattr() updates ->i_size
@@ -371,6 +378,7 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr) 
			attr->ia_valid &= ~ATTR_MODE;

	}



	if (attr->ia_valid)

		error = inode_setattr(inode, attr);

out:

	return error;

fs/fat/inode.c

+13 −4
Original line number Diff line number Diff line
@@ -797,8 +797,10 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt) 
			seq_puts(m, ",uni_xlate");

		if (!opts->numtail)

			seq_puts(m, ",nonumtail");

		if (opts->rodir)

			seq_puts(m, ",rodir");

	}

	if (sbi->options.flush)

	if (opts->flush)

		seq_puts(m, ",flush");

	if (opts->tz_utc)

		seq_puts(m, ",tz=UTC");
@@ -814,7 +816,7 @@ 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_err,

	Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err,

};



static const match_table_t fat_tokens = {
@@ -886,6 +888,7 @@ static const match_table_t vfat_tokens = { 
	{Opt_nonumtail_yes, "nonumtail=yes"},

	{Opt_nonumtail_yes, "nonumtail=true"},

	{Opt_nonumtail_yes, "nonumtail"},

	{Opt_rodir, "rodir"},

	{Opt_err, NULL}

};
@@ -905,10 +908,13 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug, 
	opts->allow_utime = -1;

	opts->codepage = fat_default_codepage;

	opts->iocharset = fat_default_iocharset;

	if (is_vfat)

	if (is_vfat) {

		opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;

	else

		opts->rodir = 0;

	} else {

		opts->shortname = 0;

		opts->rodir = 1;

	}

	opts->name_check = 'n';

	opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;

	opts->utf8 = opts->unicode_xlate = 0;
@@ -1059,6 +1065,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug, 
		case Opt_nonumtail_yes:		/* empty or 1 or yes or true */

			opts->numtail = 0;	/* negated option */

			break;

		case Opt_rodir:

			opts->rodir = 1;

			break;



		/* obsolete mount options */

		case Opt_obsolate:

CRA Git | Maintained and supported by SUSTech CRA and CCSE