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Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  quota: Fix deadlock during path resolution
This commit is contained in:
Linus Torvalds 2011-01-21 07:33:37 -08:00
parent 2b1caf6ed7 f00c9e44ad
commit 4843456c5c
8 changed files with 56 additions and 84 deletions
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25
fs/ext3/super.c
View File

@ -754,7 +754,7 @@ static int ext3_release_dquot(struct dquot *dquot);
static int ext3_mark_dquot_dirty(struct dquot *dquot);
static int ext3_write_info(struct super_block *sb, int type);
static int ext3_quota_on(struct super_block *sb, int type, int format_id,
char *path);
struct path *path);
static int ext3_quota_on_mount(struct super_block *sb, int type);
static ssize_t ext3_quota_read(struct super_block *sb, int type, char *data,
size_t len, loff_t off);
@ -2877,27 +2877,20 @@ static int ext3_quota_on_mount(struct super_block *sb, int type)
* Standard function to be called on quota_on
*/
static int ext3_quota_on(struct super_block *sb, int type, int format_id,
char *name)
struct path *path)
{
int err;
struct path path;
if (!test_opt(sb, QUOTA))
return -EINVAL;
err = kern_path(name, LOOKUP_FOLLOW, &path);
if (err)
return err;
/* Quotafile not on the same filesystem? */
if (path.mnt->mnt_sb != sb) {
path_put(&path);
if (path->mnt->mnt_sb != sb)
return -EXDEV;
}
/* Journaling quota? */
if (EXT3_SB(sb)->s_qf_names[type]) {
/* Quotafile not of fs root? */
if (path.dentry->d_parent != sb->s_root)
if (path->dentry->d_parent != sb->s_root)
ext3_msg(sb, KERN_WARNING,
"warning: Quota file not on filesystem root. "
"Journaled quota will not work.");
@ -2907,7 +2900,7 @@ static int ext3_quota_on(struct super_block *sb, int type, int format_id,
* When we journal data on quota file, we have to flush journal to see
* all updates to the file when we bypass pagecache...
*/
if (ext3_should_journal_data(path.dentry->d_inode)) {
if (ext3_should_journal_data(path->dentry->d_inode)) {
/*
* We don't need to lock updates but journal_flush() could
* otherwise be livelocked...
@ -2915,15 +2908,11 @@ static int ext3_quota_on(struct super_block *sb, int type, int format_id,
journal_lock_updates(EXT3_SB(sb)->s_journal);
err = journal_flush(EXT3_SB(sb)->s_journal);
journal_unlock_updates(EXT3_SB(sb)->s_journal);
if (err) {
path_put(&path);
if (err)
return err;
}
}
err = dquot_quota_on_path(sb, type, format_id, &path);
path_put(&path);
return err;
return dquot_quota_on(sb, type, format_id, path);
}
/* Read data from quotafile - avoid pagecache and such because we cannot afford

25
fs/ext4/super.c
View File

@ -1161,7 +1161,7 @@ static int ext4_release_dquot(struct dquot *dquot);
static int ext4_mark_dquot_dirty(struct dquot *dquot);
static int ext4_write_info(struct super_block *sb, int type);
static int ext4_quota_on(struct super_block *sb, int type, int format_id,
char *path);
struct path *path);
static int ext4_quota_off(struct super_block *sb, int type);
static int ext4_quota_on_mount(struct super_block *sb, int type);
static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
@ -4558,27 +4558,20 @@ static int ext4_quota_on_mount(struct super_block *sb, int type)
* Standard function to be called on quota_on
*/
static int ext4_quota_on(struct super_block *sb, int type, int format_id,
char *name)
struct path *path)
{
int err;
struct path path;
if (!test_opt(sb, QUOTA))
return -EINVAL;
err = kern_path(name, LOOKUP_FOLLOW, &path);
if (err)
return err;
/* Quotafile not on the same filesystem? */
if (path.mnt->mnt_sb != sb) {
path_put(&path);
if (path->mnt->mnt_sb != sb)
return -EXDEV;
}
/* Journaling quota? */
if (EXT4_SB(sb)->s_qf_names[type]) {
/* Quotafile not in fs root? */
if (path.dentry->d_parent != sb->s_root)
if (path->dentry->d_parent != sb->s_root)
ext4_msg(sb, KERN_WARNING,
"Quota file not on filesystem root. "
"Journaled quota will not work");
@ -4589,7 +4582,7 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
* all updates to the file when we bypass pagecache...
*/
if (EXT4_SB(sb)->s_journal &&
ext4_should_journal_data(path.dentry->d_inode)) {
ext4_should_journal_data(path->dentry->d_inode)) {
/*
* We don't need to lock updates but journal_flush() could
* otherwise be livelocked...
@ -4597,15 +4590,11 @@ static int ext4_quota_on(struct super_block *sb, int type, int format_id,
jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
if (err) {
path_put(&path);
if (err)
return err;
}
}
err = dquot_quota_on_path(sb, type, format_id, &path);
path_put(&path);
return err;
return dquot_quota_on(sb, type, format_id, path);
}
static int ext4_quota_off(struct super_block *sb, int type)

5
fs/ocfs2/super.c
View File

@ -993,8 +993,7 @@ static void ocfs2_disable_quotas(struct ocfs2_super *osb)
}
/* Handle quota on quotactl */
static int ocfs2_quota_on(struct super_block *sb, int type, int format_id,
char *path)
static int ocfs2_quota_on(struct super_block *sb, int type, int format_id)
{
unsigned int feature[MAXQUOTAS] = { OCFS2_FEATURE_RO_COMPAT_USRQUOTA,
OCFS2_FEATURE_RO_COMPAT_GRPQUOTA};
@ -1013,7 +1012,7 @@ static int ocfs2_quota_off(struct super_block *sb, int type)
}
static const struct quotactl_ops ocfs2_quotactl_ops = {
.quota_on = ocfs2_quota_on,
.quota_on_meta = ocfs2_quota_on,
.quota_off = ocfs2_quota_off,
.quota_sync = dquot_quota_sync,
.get_info = dquot_get_dqinfo,

18
fs/quota/dquot.c
View File

@ -2189,8 +2189,8 @@ int dquot_resume(struct super_block *sb, int type)
}
EXPORT_SYMBOL(dquot_resume);
int dquot_quota_on_path(struct super_block *sb, int type, int format_id,
struct path *path)
int dquot_quota_on(struct super_block *sb, int type, int format_id,
struct path *path)
{
int error = security_quota_on(path->dentry);
if (error)
@ -2204,20 +2204,6 @@ int dquot_quota_on_path(struct super_block *sb, int type, int format_id,
DQUOT_LIMITS_ENABLED);
return error;
}
EXPORT_SYMBOL(dquot_quota_on_path);
int dquot_quota_on(struct super_block *sb, int type, int format_id, char *name)
{
struct path path;
int error;
error = kern_path(name, LOOKUP_FOLLOW, &path);
if (!error) {
error = dquot_quota_on_path(sb, type, format_id, &path);
path_put(&path);
}
return error;
}
EXPORT_SYMBOL(dquot_quota_on);
/*

41
fs/quota/quota.c
View File

@ -64,18 +64,15 @@ static int quota_sync_all(int type)
}
static int quota_quotaon(struct super_block *sb, int type, int cmd, qid_t id,
void __user *addr)
struct path *path)
{
char *pathname;
int ret = -ENOSYS;
pathname = getname(addr);
if (IS_ERR(pathname))
return PTR_ERR(pathname);
if (sb->s_qcop->quota_on)
ret = sb->s_qcop->quota_on(sb, type, id, pathname);
putname(pathname);
return ret;
if (!sb->s_qcop->quota_on && !sb->s_qcop->quota_on_meta)
return -ENOSYS;
if (sb->s_qcop->quota_on_meta)
return sb->s_qcop->quota_on_meta(sb, type, id);
if (IS_ERR(path))
return PTR_ERR(path);
return sb->s_qcop->quota_on(sb, type, id, path);
}
static int quota_getfmt(struct super_block *sb, int type, void __user *addr)
@ -241,7 +238,7 @@ static int quota_getxquota(struct super_block *sb, int type, qid_t id,
/* Copy parameters and call proper function */
static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
void __user *addr)
void __user *addr, struct path *path)
{
int ret;
@ -256,7 +253,7 @@ static int do_quotactl(struct super_block *sb, int type, int cmd, qid_t id,
switch (cmd) {
case Q_QUOTAON:
return quota_quotaon(sb, type, cmd, id, addr);
return quota_quotaon(sb, type, cmd, id, path);
case Q_QUOTAOFF:
if (!sb->s_qcop->quota_off)
return -ENOSYS;
@ -335,6 +332,7 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
{
uint cmds, type;
struct super_block *sb = NULL;
struct path path, *pathp = NULL;
int ret;
cmds = cmd >> SUBCMDSHIFT;
@ -351,12 +349,27 @@ SYSCALL_DEFINE4(quotactl, unsigned int, cmd, const char __user *, special,
return -ENODEV;
}
/*
* Path for quotaon has to be resolved before grabbing superblock
* because that gets s_umount sem which is also possibly needed by path
* resolution (think about autofs) and thus deadlocks could arise.
*/
if (cmds == Q_QUOTAON) {
ret = user_path_at(AT_FDCWD, addr, LOOKUP_FOLLOW, &path);
if (ret)
pathp = ERR_PTR(ret);
else
pathp = &path;
}
sb = quotactl_block(special);
if (IS_ERR(sb))
return PTR_ERR(sb);
ret = do_quotactl(sb, type, cmds, id, addr);
ret = do_quotactl(sb, type, cmds, id, addr, pathp);
drop_super(sb);
if (pathp && !IS_ERR(pathp))
path_put(pathp);
return ret;
}

17
fs/reiserfs/super.c
View File

@ -632,7 +632,7 @@ static int reiserfs_acquire_dquot(struct dquot *);
static int reiserfs_release_dquot(struct dquot *);
static int reiserfs_mark_dquot_dirty(struct dquot *);
static int reiserfs_write_info(struct super_block *, int);
static int reiserfs_quota_on(struct super_block *, int, int, char *);
static int reiserfs_quota_on(struct super_block *, int, int, struct path *);
static const struct dquot_operations reiserfs_quota_operations = {
.write_dquot = reiserfs_write_dquot,
@ -2048,25 +2048,21 @@ static int reiserfs_quota_on_mount(struct super_block *sb, int type)
* Standard function to be called on quota_on
*/
static int reiserfs_quota_on(struct super_block *sb, int type, int format_id,
char *name)
struct path *path)
{
int err;
struct path path;
struct inode *inode;
struct reiserfs_transaction_handle th;
if (!(REISERFS_SB(sb)->s_mount_opt & (1 << REISERFS_QUOTA)))
return -EINVAL;
err = kern_path(name, LOOKUP_FOLLOW, &path);
if (err)
return err;
/* Quotafile not on the same filesystem? */
if (path.mnt->mnt_sb != sb) {
if (path->mnt->mnt_sb != sb) {
err = -EXDEV;
goto out;
}
inode = path.dentry->d_inode;
inode = path->dentry->d_inode;
/* We must not pack tails for quota files on reiserfs for quota IO to work */
if (!(REISERFS_I(inode)->i_flags & i_nopack_mask)) {
err = reiserfs_unpack(inode, NULL);
@ -2082,7 +2078,7 @@ static int reiserfs_quota_on(struct super_block *sb, int type, int format_id,
/* Journaling quota? */
if (REISERFS_SB(sb)->s_qf_names[type]) {
/* Quotafile not of fs root? */
if (path.dentry->d_parent != sb->s_root)
if (path->dentry->d_parent != sb->s_root)
reiserfs_warning(sb, "super-6521",
"Quota file not on filesystem root. "
"Journalled quota will not work.");
@ -2101,9 +2097,8 @@ static int reiserfs_quota_on(struct super_block *sb, int type, int format_id,
if (err)
goto out;
}
err = dquot_quota_on_path(sb, type, format_id, &path);
err = dquot_quota_on(sb, type, format_id, path);
out:
path_put(&path);
return err;
}

5
include/linux/quota.h
View File

@ -322,9 +322,12 @@ struct dquot_operations {
qsize_t *(*get_reserved_space) (struct inode *);
};
struct path;
/* Operations handling requests from userspace */
struct quotactl_ops {
int (*quota_on)(struct super_block *, int, int, char *);
int (*quota_on)(struct super_block *, int, int, struct path *);
int (*quota_on_meta)(struct super_block *, int, int);
int (*quota_off)(struct super_block *, int);
int (*quota_sync)(struct super_block *, int, int);
int (*get_info)(struct super_block *, int, struct if_dqinfo *);

4
include/linux/quotaops.h
View File

@ -76,11 +76,9 @@ int dquot_mark_dquot_dirty(struct dquot *dquot);
int dquot_file_open(struct inode *inode, struct file *file);
int dquot_quota_on(struct super_block *sb, int type, int format_id,
char *path);
int dquot_enable(struct inode *inode, int type, int format_id,
unsigned int flags);
int dquot_quota_on_path(struct super_block *sb, int type, int format_id,
int dquot_quota_on(struct super_block *sb, int type, int format_id,
struct path *path);
int dquot_quota_on_mount(struct super_block *sb, char *qf_name,
int format_id, int type);