diff options
Diffstat (limited to 'fs/sdcardfs/dentry.c')
| -rwxr-xr-x[-rw-r--r--] | fs/sdcardfs/dentry.c | 69 |
1 files changed, 43 insertions, 26 deletions
diff --git a/fs/sdcardfs/dentry.c b/fs/sdcardfs/dentry.c index ba165ef1..80d21dbe 100644..100755 --- a/fs/sdcardfs/dentry.c +++ b/fs/sdcardfs/dentry.c @@ -1,21 +1,19 @@ /* * fs/sdcardfs/dentry.c * - * Copyright (c) 2013 Samsung Electronics Co. Ltd - * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun, - * Sunghwan Yun, Sungjong Seo + * Copyright (c) 2015 Lenovo Co. Ltd + * Authors: liaohs , jixj + +* This program has been developed as a stackable file system based on + * the WrapFS which written by + * Copyright (c) 1998-2014 Erez Zadok + * Copyright (c) 2009 Shrikar Archak + * Copyright (c) 2003-2014 Stony Brook University + * Copyright (c) 2003-2014 The Research Foundation of SUNY * - * This program has been developed as a stackable file system based on - * the WrapFS which written by - * - * Copyright (c) 1998-2011 Erez Zadok - * Copyright (c) 2009 Shrikar Archak - * Copyright (c) 2003-2011 Stony Brook University - * Copyright (c) 2003-2011 The Research Foundation of SUNY - * - * This file is dual licensed. It may be redistributed and/or modified - * under the terms of the Apache 2.0 License OR version 2 of the GNU - * General Public License. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. */ #include "sdcardfs.h" @@ -45,7 +43,7 @@ static int sdcardfs_d_revalidate(struct dentry *dentry, unsigned int flags) } spin_unlock(&dentry->d_lock); - /* check uninitialized obb_dentry and + /* check uninitialized obb_dentry and * whether the base obbpath has been changed or not */ if (is_obbpath_invalid(dentry)) { d_drop(dentry); @@ -74,12 +72,32 @@ static int sdcardfs_d_revalidate(struct dentry *dentry, unsigned int flags) goto out; } +/* ######## ATTENTION ######## +~~~ spin_lock(&lower_dentry->d_lock); //here call spin_lock , will cause follow DEADLOCK ~~ + +4>[ 38.406030]-(1)[829:zygote] (&(&dentry->d_lock)->rlock){+.+...}, at: [<c026a6c4>] sdcardfs_d_revalidate+0x1b8/0x258 +<4>[ 38.406057]-(1)[829:zygote] +<4>[ 38.406062]-(1)[829:zygote]but task is already holding lock: +<4>[ 38.406069]-(1)[829:zygote] (&(&dentry->d_lock)->rlock){+.+...}, at: [<c026a6bc>] sdcardfs_d_revalidate+0x1b0/0x258 +<4>[ 38.406094]-(1)[829:zygote] +<4>[ 38.406098]-(1)[829:zygote]other info that might help us debug this: +<4>[ 38.406107]-(1)[829:zygote] Possible unsafe locking scenario: +<4>[ 38.406113]-(1)[829:zygote] +<4>[ 38.406119]-(1)[829:zygote] CPU0 +<4>[ 38.406125]-(1)[829:zygote] ---- +<4>[ 38.406132]-(1)[829:zygote] lock(&(&dentry->d_lock)->rlock); +<4>[ 38.406143]-(1)[829:zygote] lock(&(&dentry->d_lock)->rlock); +<4>[ 38.406153]-(1)[829:zygote] +<4>[ 38.406158]-(1)[829:zygote] *** DEADLOCK *** +<4>[ 38.406163]-(1)[829:zygote] +<4>[ 38.406169]-(1)[829:zygote] May be due to missing lock nesting notation + */ if (dentry < lower_dentry) { spin_lock(&dentry->d_lock); - spin_lock(&lower_dentry->d_lock); + spin_lock_nested(&lower_dentry->d_lock, 1); } else { spin_lock(&lower_dentry->d_lock); - spin_lock(&dentry->d_lock); + spin_lock_nested(&dentry->d_lock, 1); } if (dentry->d_name.len != lower_dentry->d_name.len) { @@ -118,10 +136,10 @@ static void sdcardfs_d_release(struct dentry *dentry) return; } -static int sdcardfs_hash_ci(const struct dentry *dentry, +static int sdcardfs_hash_ci(const struct dentry *dentry, struct qstr *qstr) { - /* + /* * This function is copy of vfat_hashi. * FIXME Should we support national language? * Refer to vfat_hashi() @@ -133,7 +151,7 @@ static int sdcardfs_hash_ci(const struct dentry *dentry, name = qstr->name; //len = vfat_striptail_len(qstr); - len = qstr->len; + len = qstr->len; hash = init_name_hash(); while (len--) @@ -147,12 +165,12 @@ static int sdcardfs_hash_ci(const struct dentry *dentry, /* * Case insensitive compare of two vfat names. */ -static int sdcardfs_cmp_ci(const struct dentry *parent, - const struct dentry *dentry, +static int sdcardfs_cmp_ci(const struct dentry *parent, + const struct dentry *dentry, unsigned int len, const char *str, const struct qstr *name) { /* This function is copy of vfat_cmpi */ - // FIXME Should we support national language? + // FIXME Should we support national language? //struct nls_table *t = MSDOS_SB(parent->d_sb)->nls_io; //unsigned int alen, blen; @@ -167,7 +185,7 @@ static int sdcardfs_cmp_ci(const struct dentry *parent, */ if (name->len == len) { if (strncasecmp(name->name, str, len) == 0) - return 0; + return 0; } return 1; } @@ -175,8 +193,7 @@ static int sdcardfs_cmp_ci(const struct dentry *parent, const struct dentry_operations sdcardfs_ci_dops = { .d_revalidate = sdcardfs_d_revalidate, .d_release = sdcardfs_d_release, - .d_hash = sdcardfs_hash_ci, + .d_hash = sdcardfs_hash_ci, .d_compare = sdcardfs_cmp_ci, - .d_canonical_path = sdcardfs_get_real_lower, }; |