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-rw-r--r--Documentation/filesystems/vfat.txt8
-rw-r--r--fs/fat/fat.h14
-rw-r--r--fs/fat/file.c16
-rw-r--r--fs/fat/inode.c17
4 files changed, 43 insertions, 12 deletions
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index dc9dc73d7d38..3a5ddc96901a 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -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
diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index 313b645b8126..e9dce5d8e7a7 100644
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -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)
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 81b15c623803..f06a4e525ece 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -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;
}
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 7aaa21cf019a..0da04e6d1e34 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -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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