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| author | Bob Peterson <rpeterso@redhat.com> | 2012-06-13 16:27:41 +0200 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2012-06-13 16:59:48 +0200 |
| commit | 0d515210b6969ecfc161f71a4515831d9a6e58f4 (patch) | |
| tree | 2e5a5da49dae5d8c036d56fc7ae14532044dfac3 /fs/gfs2/sys.c | |
| parent | GFS2: Size seq_file buffer more carefully (diff) | |
| download | linux-0d515210b6969ecfc161f71a4515831d9a6e58f4.tar.xz linux-0d515210b6969ecfc161f71a4515831d9a6e58f4.zip | |
GFS2: Add kobject release method
This patch adds a kobject release function that properly maintains
the kobject use count, so that accesses to the sysfs files do not
cause an access to freed kernel memory after an unmount.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/sys.c')
| -rw-r--r-- | fs/gfs2/sys.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c index 9c2592b1d5ff..e4bee4bebbf6 100644 --- a/fs/gfs2/sys.c +++ b/fs/gfs2/sys.c @@ -276,7 +276,15 @@ static struct attribute *gfs2_attrs[] = { NULL, }; +static void gfs2_sbd_release(struct kobject *kobj) +{ + struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj); + + kfree(sdp); +} + static struct kobj_type gfs2_ktype = { + .release = gfs2_sbd_release, .default_attrs = gfs2_attrs, .sysfs_ops = &gfs2_attr_ops, }; @@ -583,6 +591,7 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp) char ro[20]; char spectator[20]; char *envp[] = { ro, spectator, NULL }; + int sysfs_frees_sdp = 0; sprintf(ro, "RDONLY=%d", (sb->s_flags & MS_RDONLY) ? 1 : 0); sprintf(spectator, "SPECTATOR=%d", sdp->sd_args.ar_spectator ? 1 : 0); @@ -591,8 +600,10 @@ int gfs2_sys_fs_add(struct gfs2_sbd *sdp) error = kobject_init_and_add(&sdp->sd_kobj, &gfs2_ktype, NULL, "%s", sdp->sd_table_name); if (error) - goto fail; + goto fail_reg; + sysfs_frees_sdp = 1; /* Freeing sdp is now done by sysfs calling + function gfs2_sbd_release. */ error = sysfs_create_group(&sdp->sd_kobj, &tune_group); if (error) goto fail_reg; @@ -615,9 +626,13 @@ fail_lock_module: fail_tune: sysfs_remove_group(&sdp->sd_kobj, &tune_group); fail_reg: - kobject_put(&sdp->sd_kobj); -fail: + free_percpu(sdp->sd_lkstats); fs_err(sdp, "error %d adding sysfs files", error); + if (sysfs_frees_sdp) + kobject_put(&sdp->sd_kobj); + else + kfree(sdp); + sb->s_fs_info = NULL; return error; } |