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

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: 's avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9183482f
......@@ -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
......
......@@ -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)
......
......@@ -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 ((perm & S_IWUGO) && ((perm & S_IWUGO) != (S_IWUGO & ~mask)))
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
......@@ -371,7 +378,8 @@ int fat_setattr(struct dentry *dentry, struct iattr *attr)
attr->ia_valid &= ~ATTR_MODE;
}
error = inode_setattr(inode, attr);
if (attr->ia_valid)
error = inode_setattr(inode, attr);
out:
return error;
}
......
......@@ -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:
......
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