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author | Curt Wohlgemuth <curtw@google.com> | 2009-09-29 11:01:03 -0400 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2009-09-29 11:01:03 -0400 |
commit | d3d1faf6a74496ea4435fd057c6a2cad49f3e523 (patch) | |
tree | 9f1cc0e2efb9a4fe42bb6b57c087d8450a854dc1 | |
parent | f3dc272fd5e2ae08244796bb39e7e1ce4b25d3b3 (diff) | |
download | kernel_samsung_smdk4412-d3d1faf6a74496ea4435fd057c6a2cad49f3e523.zip kernel_samsung_smdk4412-d3d1faf6a74496ea4435fd057c6a2cad49f3e523.tar.gz kernel_samsung_smdk4412-d3d1faf6a74496ea4435fd057c6a2cad49f3e523.tar.bz2 |
ext4: Handle nested ext4_journal_start/stop calls without a journal
This patch fixes a problem with handling nested calls to
ext4_journal_start/ext4_journal_stop, when there is no journal present.
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
-rw-r--r-- | fs/ext4/ext4_jbd2.h | 6 | ||||
-rw-r--r-- | fs/ext4/namei.c | 3 | ||||
-rw-r--r-- | fs/ext4/super.c | 42 |
3 files changed, 38 insertions, 13 deletions
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index 139fb8c..a286598 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -161,11 +161,13 @@ int __ext4_handle_dirty_metadata(const char *where, handle_t *handle, handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks); int __ext4_journal_stop(const char *where, handle_t *handle); -#define EXT4_NOJOURNAL_HANDLE ((handle_t *) 0x1) +#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096) +/* Note: Do not use this for NULL handles. This is only to determine if + * a properly allocated handle is using a journal or not. */ static inline int ext4_handle_valid(handle_t *handle) { - if (handle == EXT4_NOJOURNAL_HANDLE) + if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT) return 0; return 1; } diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 42f81d2..7c8fe80 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2076,7 +2076,8 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) struct ext4_iloc iloc; int err = 0; - if (!ext4_handle_valid(handle)) + /* ext4_handle_valid() assumes a valid handle_t pointer */ + if (handle && !ext4_handle_valid(handle)) return 0; mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f095c60..3f7e701 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -189,6 +189,36 @@ void ext4_itable_unused_set(struct super_block *sb, bg->bg_itable_unused_hi = cpu_to_le16(count >> 16); } + +/* Just increment the non-pointer handle value */ +static handle_t *ext4_get_nojournal(void) +{ + handle_t *handle = current->journal_info; + unsigned long ref_cnt = (unsigned long)handle; + + BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT); + + ref_cnt++; + handle = (handle_t *)ref_cnt; + + current->journal_info = handle; + return handle; +} + + +/* Decrement the non-pointer handle value */ +static void ext4_put_nojournal(handle_t *handle) +{ + unsigned long ref_cnt = (unsigned long)handle; + + BUG_ON(ref_cnt == 0); + + ref_cnt--; + handle = (handle_t *)ref_cnt; + + current->journal_info = handle; +} + /* * Wrappers for jbd2_journal_start/end. * @@ -215,11 +245,7 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks) } return jbd2_journal_start(journal, nblocks); } - /* - * We're not journaling, return the appropriate indication. - */ - current->journal_info = EXT4_NOJOURNAL_HANDLE; - return current->journal_info; + return ext4_get_nojournal(); } /* @@ -235,11 +261,7 @@ int __ext4_journal_stop(const char *where, handle_t *handle) int rc; if (!ext4_handle_valid(handle)) { - /* - * Do this here since we don't call jbd2_journal_stop() in - * no-journal mode. - */ - current->journal_info = NULL; + ext4_put_nojournal(handle); return 0; } sb = handle->h_transaction->t_journal->j_private; |