diff options
| author | Ian Kent <raven@themaw.net> | 2005-06-21 17:16:38 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-06-21 19:07:35 -0700 |
| commit | 9b1e3afd6d56937ced3914971621d0f053ea9178 (patch) | |
| tree | 059762a20c069273247b423b6075adcd89624e42 | |
| parent | 8818760512424f60ad9fafb7a087b007a9274eb3 (diff) | |
| download | lwn-9b1e3afd6d56937ced3914971621d0f053ea9178.tar.gz lwn-9b1e3afd6d56937ced3914971621d0f053ea9178.zip | |
[PATCH] autofs4: avoid panic on bind mount of autofs owned directory
While this is not a solution to bind and move mounts on autofs owned
directories it is necessary to fix the trady error handling.
At least it avoids the kernel panic I observed checking out bug #4589.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/autofs4/autofs_i.h | 13 | ||||
| -rw-r--r-- | fs/autofs4/expire.c | 5 | ||||
| -rw-r--r-- | fs/autofs4/root.c | 6 |
3 files changed, 19 insertions, 5 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index c7b2b8890188..9c09641ce907 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -185,6 +185,19 @@ int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify); int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int); void autofs4_catatonic_mode(struct autofs_sb_info *); +static inline int autofs4_follow_mount(struct vfsmount **mnt, struct dentry **dentry) +{ + int res = 0; + + while (d_mountpoint(*dentry)) { + int followed = follow_down(mnt, dentry); + if (!followed) + break; + res = 1; + } + return res; +} + static inline int simple_positive(struct dentry *dentry) { return dentry->d_inode && !d_unhashed(dentry); diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 500425e24fba..feb6ac427d05 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -56,12 +56,9 @@ static int autofs4_check_mount(struct vfsmount *mnt, struct dentry *dentry) mntget(mnt); dget(dentry); - if (!follow_down(&mnt, &dentry)) + if (!autofs4_follow_mount(&mnt, &dentry)) goto done; - while (d_mountpoint(dentry) && follow_down(&mnt, &dentry)) - ; - /* This is an autofs submount, we can't expire it */ if (is_autofs4_dentry(dentry)) goto done; diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 3765c047f157..e137acf0543d 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -205,7 +205,11 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) struct vfsmount *fp_mnt = mntget(mnt); struct dentry *fp_dentry = dget(dentry); - while (follow_down(&fp_mnt, &fp_dentry) && d_mountpoint(fp_dentry)); + if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { + dput(fp_dentry); + mntput(fp_mnt); + return -ENOENT; + } fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); status = PTR_ERR(fp); |