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Message-Id: <1343908443-17369-4-git-send-email-ludwig.nussel@suse.de>
Date: Thu, 2 Aug 2012 13:54:03 +0200
From: Ludwig Nussel <ludwig.nussel@...e.de>
To: linux-kernel@...r.kernel.org
Cc: Ludwig Nussel <ludwig.nussel@...e.de>,
linux-fsdevel@...r.kernel.org,
Jan Kara <jack@...e.cz> (maintainer:EXT2 FILE SYSTEM),
Rob Landley <rob@...dley.net> (maintainer:DOCUMENTATION),
Andrew Morton <akpm@...ux-foundation.org> (maintainer:EXT3 FILE
SYSTEM),
Andreas Dilger <adilger.kernel@...ger.ca> (maintainer:EXT3 FILE
SYSTEM),
"Theodore Ts'o" <tytso@....edu> (maintainer:EXT4 FILE SYSTEM),
linux-ext4@...r.kernel.org (open list:EXT2 FILE SYSTEM),
linux-doc@...r.kernel.org (open list:DOCUMENTATION)
Subject: [PATCH 3/3] implement uid and gid mount options for ext4
Signed-off-by: Ludwig Nussel <ludwig.nussel@...e.de>
---
Documentation/filesystems/ext4.txt | 9 ++++
fs/ext4/ext4.h | 4 ++
fs/ext4/inode.c | 52 +++++++++++++++------
fs/ext4/super.c | 87 +++++++++++++++++++++++++++++++++++-
4 Dateien geändert, 137 Zeilen hinzugefügt(+), 15 Zeilen entfernt(-)
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 1b7f9ac..b388ab5 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -245,6 +245,15 @@ resgid=n The group ID which may use the reserved blocks.
resuid=n The user ID which may use the reserved blocks.
+uid=n[:m] Make all files appear to belong to uid n.
+ Useful for e.g. removable media with fstab
+ options 'user,uid=useruid'. The optional second
+ uid m is actually written to the file system.
+
+gid=n[:m] Make all files appear to belong to gid n.
+ The optional second gid m is actually written to
+ the file system.
+
sb=n Use alternate superblock at this location.
quota These options are ignored by the filesystem. They
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index c3411d4..070e3ad 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1177,6 +1177,10 @@ struct ext4_sb_info {
ext4_fsblk_t s_sb_block;
kuid_t s_resuid;
kgid_t s_resgid;
+ kuid_t s_uid; /* make all files appear to belong to this uid */
+ kuid_t s_diskuid; /* write this uid to disk (if s_uid != 0) */
+ kgid_t s_gid; /* make all files appear to belong to this gid */
+ kgid_t s_diskgid; /* write this gid to disk (if s_gid != 0) */
unsigned short s_mount_state;
unsigned short s_pad;
int s_addr_per_block_bits;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 6324f74..b02ec15 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3838,8 +3838,14 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
}
- i_uid_write(inode, i_uid);
- i_gid_write(inode, i_gid);
+ if (uid_valid(EXT4_SB(sb)->s_uid))
+ inode->i_uid = EXT4_SB(sb)->s_uid;
+ else
+ i_uid_write(inode, i_uid);
+ if (gid_valid(EXT4_SB(sb)->s_gid))
+ inode->i_gid = EXT4_SB(sb)->s_gid;
+ else
+ i_gid_write(inode, i_gid);
set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
@@ -4054,6 +4060,10 @@ static int ext4_do_update_inode(handle_t *handle,
int err = 0, rc, block;
uid_t i_uid;
gid_t i_gid;
+ __le16 uid_low;
+ __le16 gid_low;
+ __le16 uid_high;
+ __le16 gid_high;
/* For fields not not tracking in the in-memory inode,
* initialise them to zero for new inodes. */
@@ -4064,28 +4074,42 @@ static int ext4_do_update_inode(handle_t *handle,
raw_inode->i_mode = cpu_to_le16(inode->i_mode);
i_uid = i_uid_read(inode);
i_gid = i_gid_read(inode);
+ if (uid_valid(EXT4_SB(inode->i_sb)->s_uid))
+ i_uid = from_kuid(&init_user_ns, EXT4_SB(inode->i_sb)->s_diskuid);
+ if (gid_valid(EXT4_SB(inode->i_sb)->s_gid))
+ i_gid = from_kgid(&init_user_ns, EXT4_SB(inode->i_sb)->s_diskgid);
if (!(test_opt(inode->i_sb, NO_UID32))) {
- raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
- raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
+ uid_low = cpu_to_le16(low_16_bits(i_uid));
+ gid_low = cpu_to_le16(low_16_bits(i_gid));
/*
* Fix up interoperability with old kernels. Otherwise, old inodes get
* re-used with the upper 16 bits of the uid/gid intact
*/
if (!ei->i_dtime) {
- raw_inode->i_uid_high =
- cpu_to_le16(high_16_bits(i_uid));
- raw_inode->i_gid_high =
- cpu_to_le16(high_16_bits(i_gid));
+ uid_high = cpu_to_le16(high_16_bits(i_uid));
+ gid_high = cpu_to_le16(high_16_bits(i_gid));
} else {
- raw_inode->i_uid_high = 0;
- raw_inode->i_gid_high = 0;
+ uid_high = 0;
+ gid_high = 0;
}
} else {
- raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
- raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
- raw_inode->i_uid_high = 0;
- raw_inode->i_gid_high = 0;
+ uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
+ gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
+ uid_high = 0;
+ gid_high = 0;
+ }
+ /* don't mangle uid/gid of existing files if override is active */
+ if (!uid_valid(EXT4_SB(inode->i_sb)->s_uid) ||
+ ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
+ raw_inode->i_uid_high = uid_high;
+ raw_inode->i_uid_low = uid_low;
}
+ if (!gid_valid(EXT4_SB(inode->i_sb)->s_gid) ||
+ ext4_test_inode_state(inode, EXT4_STATE_NEW)) {
+ raw_inode->i_gid_high = gid_high;
+ raw_inode->i_gid_low = gid_low;
+ }
+
raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d76ec82..927c020 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1229,6 +1229,7 @@ enum {
Opt_inode_readahead_blks, Opt_journal_ioprio,
Opt_dioread_nolock, Opt_dioread_lock,
Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
+ Opt_uid, Opt_diskuid, Opt_gid, Opt_diskgid,
};
static const match_table_t tokens = {
@@ -1307,6 +1308,10 @@ static const match_table_t tokens = {
{Opt_removed, "reservation"}, /* mount option from ext2/3 */
{Opt_removed, "noreservation"}, /* mount option from ext2/3 */
{Opt_removed, "journal=%u"}, /* mount option from ext2/3 */
+ {Opt_uid, "uid=%u"},
+ {Opt_diskuid, "uid=%u:%u"},
+ {Opt_gid, "gid=%u"},
+ {Opt_diskgid, "gid=%u:%u"},
{Opt_err, NULL},
};
@@ -1553,6 +1558,54 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
return -1;
*journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
return 1;
+ case Opt_uid:
+ uid = make_kuid(current_user_ns(), arg);
+ if (!uid_valid(uid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
+ return -1;
+ }
+ sbi->s_uid = sbi->s_diskuid = uid;
+ return 1;
+ case Opt_diskuid:
+ uid = make_kuid(current_user_ns(), arg);
+ if (!uid_valid(uid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
+ return -1;
+ }
+ sbi->s_uid = uid;
+ if (match_int(&args[1], &arg))
+ return -1;
+ uid = make_kuid(current_user_ns(), arg);
+ if (!uid_valid(uid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid uid value %d", arg);
+ return -1;
+ }
+ sbi->s_diskuid = uid;
+ return 1;
+ case Opt_gid:
+ gid = make_kgid(current_user_ns(), arg);
+ if (!gid_valid(gid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+ return -1;
+ }
+ sbi->s_gid = sbi->s_diskgid = gid;
+ return 1;
+ case Opt_diskgid:
+ gid = make_kgid(current_user_ns(), arg);
+ if (!gid_valid(gid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+ return -1;
+ }
+ sbi->s_gid = gid;
+ if (match_int(&args[1], &arg))
+ return -1;
+ gid = make_kgid(current_user_ns(), arg);
+ if (!gid_valid(gid)) {
+ ext4_msg(sb, KERN_ERR, "Invalid gid value %d", arg);
+ return -1;
+ }
+ sbi->s_diskgid = gid;
+ return 1;
}
for (m = ext4_mount_opts; m->token != Opt_err; m++) {
@@ -1768,7 +1821,7 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
char sep = nodefs ? '\n' : ',';
#define SEQ_OPTS_PUTS(str) seq_printf(seq, "%c" str, sep)
-#define SEQ_OPTS_PRINT(str, arg) seq_printf(seq, "%c" str, sep, arg)
+#define SEQ_OPTS_PRINT(str, args...) seq_printf(seq, "%c" str, sep, ##args)
if (sbi->s_sb_block != 1)
SEQ_OPTS_PRINT("sb=%llu", sbi->s_sb_block);
@@ -1795,6 +1848,22 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
SEQ_OPTS_PRINT("resgid=%u",
from_kgid_munged(&init_user_ns, sbi->s_resgid));
+ if (uid_valid(sbi->s_uid)) {
+ if (!uid_eq(sbi->s_uid, sbi->s_diskuid))
+ SEQ_OPTS_PRINT("uid=%u:%u",
+ from_kuid_munged(&init_user_ns, sbi->s_uid),
+ from_kuid_munged(&init_user_ns, sbi->s_diskuid));
+ else
+ SEQ_OPTS_PRINT("uid=%u", from_kuid_munged(&init_user_ns, sbi->s_uid));
+ }
+ if (gid_valid(sbi->s_gid)) {
+ if (!gid_eq(sbi->s_gid, sbi->s_diskgid))
+ SEQ_OPTS_PRINT("gid=%u:%u",
+ from_kgid_munged(&init_user_ns, sbi->s_gid),
+ from_kgid_munged(&init_user_ns, sbi->s_diskgid));
+ else
+ SEQ_OPTS_PRINT("gid=%u", from_kgid_munged(&init_user_ns, sbi->s_gid));
+ }
def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
if (test_opt(sb, ERRORS_RO) && def_errors != EXT4_ERRORS_RO)
SEQ_OPTS_PUTS("errors=remount-ro");
@@ -3243,6 +3312,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
sbi->s_mount_opt = 0;
sbi->s_resuid = make_kuid(&init_user_ns, EXT4_DEF_RESUID);
sbi->s_resgid = make_kgid(&init_user_ns, EXT4_DEF_RESGID);
+ sbi->s_uid = INVALID_UID;
+ sbi->s_gid = INVALID_GID;
+ sbi->s_diskuid = INVALID_UID;
+ sbi->s_diskgid = INVALID_GID;
sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
sbi->s_sb_block = sb_block;
if (sb->s_bdev->bd_part)
@@ -4535,6 +4608,10 @@ struct ext4_mount_options {
unsigned long s_mount_opt2;
kuid_t s_resuid;
kgid_t s_resgid;
+ kuid_t s_uid;
+ kuid_t s_diskuid;
+ kgid_t s_gid;
+ kgid_t s_diskgid;
unsigned long s_commit_interval;
u32 s_min_batch_time, s_max_batch_time;
#ifdef CONFIG_QUOTA
@@ -4565,6 +4642,10 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
old_opts.s_mount_opt2 = sbi->s_mount_opt2;
old_opts.s_resuid = sbi->s_resuid;
old_opts.s_resgid = sbi->s_resgid;
+ old_opts.s_uid = sbi->s_uid;
+ old_opts.s_diskuid = sbi->s_diskuid;
+ old_opts.s_gid = sbi->s_gid;
+ old_opts.s_diskgid = sbi->s_diskgid;
old_opts.s_commit_interval = sbi->s_commit_interval;
old_opts.s_min_batch_time = sbi->s_min_batch_time;
old_opts.s_max_batch_time = sbi->s_max_batch_time;
@@ -4732,6 +4813,10 @@ restore_opts:
sbi->s_mount_opt2 = old_opts.s_mount_opt2;
sbi->s_resuid = old_opts.s_resuid;
sbi->s_resgid = old_opts.s_resgid;
+ sbi->s_uid = old_opts.s_uid;
+ sbi->s_diskuid = old_opts.s_diskuid;
+ sbi->s_gid = old_opts.s_gid;
+ sbi->s_diskgid = old_opts.s_diskgid;
sbi->s_commit_interval = old_opts.s_commit_interval;
sbi->s_min_batch_time = old_opts.s_min_batch_time;
sbi->s_max_batch_time = old_opts.s_max_batch_time;
--
1.7.10.4
--
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