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| author | Takashi Iwai <tiwai@suse.de> | 2009-05-29 11:46:10 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2009-05-29 11:46:10 +0200 |
| commit | e93721a70263afefbac781f575bfe851c6f95d84 (patch) | |
| tree | ab359f12a0688802aa99339bae82c51763dae9f6 /fs/namespace.c | |
| parent | ae1ec5e1e97f67d41e641a73380129e5905e41cc (diff) | |
| parent | c87d9732004b3f8fd82d729f12ccfb96c0df279e (diff) | |
Merge branch 'fix/pcm-jiffies-check' into topic/pcm-jiffies-check
Diffstat (limited to 'fs/namespace.c')
| -rw-r--r-- | fs/namespace.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 41196209a906..134d494158d9 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -695,12 +695,16 @@ static inline void mangle(struct seq_file *m, const char *s) */ int generic_show_options(struct seq_file *m, struct vfsmount *mnt) { - const char *options = mnt->mnt_sb->s_options; + const char *options; + + rcu_read_lock(); + options = rcu_dereference(mnt->mnt_sb->s_options); if (options != NULL && options[0]) { seq_putc(m, ','); mangle(m, options); } + rcu_read_unlock(); return 0; } @@ -721,11 +725,22 @@ EXPORT_SYMBOL(generic_show_options); */ void save_mount_options(struct super_block *sb, char *options) { - kfree(sb->s_options); - sb->s_options = kstrdup(options, GFP_KERNEL); + BUG_ON(sb->s_options); + rcu_assign_pointer(sb->s_options, kstrdup(options, GFP_KERNEL)); } EXPORT_SYMBOL(save_mount_options); +void replace_mount_options(struct super_block *sb, char *options) +{ + char *old = sb->s_options; + rcu_assign_pointer(sb->s_options, options); + if (old) { + synchronize_rcu(); + kfree(old); + } +} +EXPORT_SYMBOL(replace_mount_options); + #ifdef CONFIG_PROC_FS /* iterator */ static void *m_start(struct seq_file *m, loff_t *pos) @@ -1073,9 +1088,7 @@ static int do_umount(struct vfsmount *mnt, int flags) */ if (flags & MNT_FORCE && sb->s_op->umount_begin) { - lock_kernel(); sb->s_op->umount_begin(sb); - unlock_kernel(); } /* |