From dfc209c0064efef5590f608056a48b61a5cac09c Mon Sep 17 00:00:00 2001 From: OGAWA Hirofumi Date: Thu, 6 Nov 2008 12:53:55 -0800 Subject: [PATCH] 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: OGAWA Hirofumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/filesystems/vfat.txt | 8 ++++++++ fs/fat/fat.h | 14 ++++++++++---- fs/fat/file.c | 16 ++++++++++++---- fs/fat/inode.c | 17 +++++++++++++---- 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. + : 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: -- 2.20.1