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authorLinus Torvalds <torvalds@linux-foundation.org>2011-01-21 07:33:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-01-21 07:33:37 -0800
commit4843456c5c341eb57f80f9224362a22665d14107 (patch)
tree5656b405a8b1d2596e8eb748b953ee677a261e3c /fs
parent2b1caf6ed7b888c95a1909d343799672731651a5 (diff)
parentf00c9e44ad1a9660fe8cd3ca15b6cd9497172eab (diff)
downloadlinux-4843456c5c341eb57f80f9224362a22665d14107.tar.bz2
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
Diffstat (limited to 'fs')
-rw-r--r--fs/ext3/super.c25
-rw-r--r--fs/ext4/super.c25
-rw-r--r--fs/ocfs2/super.c5
-rw-r--r--fs/quota/dquot.c18
-rw-r--r--fs/quota/quota.c41
-rw-r--r--fs/reiserfs/super.c17
6 files changed, 51 insertions, 80 deletions
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 7aa767d4f06f..85c8cc8f2473 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -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
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index cb10a06775e4..48ce561fafac 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -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)
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index 06d1f749ca89..38f986d2447e 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -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,
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 84becd3e4772..a2a622e079f0 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -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);
/*
diff --git a/fs/quota/quota.c b/fs/quota/quota.c
index b299961e1edb..b34bdb25490c 100644
--- a/fs/quota/quota.c
+++ b/fs/quota/quota.c
@@ -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;
}
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 2575682a9ead..0aab04f46827 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -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;
}