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author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-21 18:33:37 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-21 18:33:37 +0300 |
commit | 4843456c5c341eb57f80f9224362a22665d14107 (patch) | |
tree | 5656b405a8b1d2596e8eb748b953ee677a261e3c /fs | |
parent | 2b1caf6ed7b888c95a1909d343799672731651a5 (diff) | |
parent | f00c9e44ad1a9660fe8cd3ca15b6cd9497172eab (diff) | |
download | linux-4843456c5c341eb57f80f9224362a22665d14107.tar.xz |
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.c | 25 | ||||
-rw-r--r-- | fs/ext4/super.c | 25 | ||||
-rw-r--r-- | fs/ocfs2/super.c | 5 | ||||
-rw-r--r-- | fs/quota/dquot.c | 18 | ||||
-rw-r--r-- | fs/quota/quota.c | 41 | ||||
-rw-r--r-- | fs/reiserfs/super.c | 17 |
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; } |