Messages in this thread Patch in this message | | | Date | Sat, 4 Jun 2005 14:10:16 +0800 (WST) | From | raven@themaw ... | Subject | [PATCH] autofs4 - avoid panic on bind mount of autofs owned directory (fwd) |
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---------- Forwarded message ---------- Date: Sat, 4 Jun 2005 14:02:36 +0800 (WST) From: raven@themaw.net To: Andrew Morton <akpm@osdl.org> Cc: Dan@Merillat.org, Steinar H. Gunderson <sgunderson@bigfoot.com>, Michael Blandford <michael@kmaclub.com>, Jeff Moyer <jmoyer@redhat.com> Subject: [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>
diff -Nurp linux-2.6.12-rc5-mm1.orig/fs/autofs4/autofs_i.h linux-2.6.12-rc5-mm1/fs/autofs4/autofs_i.h --- linux-2.6.12-rc5-mm1.orig/fs/autofs4/autofs_i.h 2005-05-29 14:37:27.000000000 +0800 +++ linux-2.6.12-rc5-mm1/fs/autofs4/autofs_i.h 2005-05-29 14:32:35.000000000 +0800 @@ -185,6 +185,19 @@ int autofs4_wait(struct autofs_sb_info * 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 -Nurp linux-2.6.12-rc5-mm1.orig/fs/autofs4/expire.c linux-2.6.12-rc5-mm1/fs/autofs4/expire.c --- linux-2.6.12-rc5-mm1.orig/fs/autofs4/expire.c 2005-05-29 14:37:27.000000000 +0800 +++ linux-2.6.12-rc5-mm1/fs/autofs4/expire.c 2005-05-29 14:32:35.000000000 +0800 @@ -56,12 +56,9 @@ static int autofs4_check_mount(struct vf 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 -Nurp linux-2.6.12-rc5-mm1.orig/fs/autofs4/root.c linux-2.6.12-rc5-mm1/fs/autofs4/root.c --- linux-2.6.12-rc5-mm1.orig/fs/autofs4/root.c 2005-05-29 14:37:27.000000000 +0800 +++ linux-2.6.12-rc5-mm1/fs/autofs4/root.c 2005-05-29 14:32:35.000000000 +0800 @@ -205,7 +205,11 @@ static int autofs4_dir_open(struct inode 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); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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