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authorTheodore Ts'o <tytso@mit.edu>2017-01-11 21:50:46 -0500
committerTheodore Ts'o <tytso@mit.edu>2017-01-11 21:50:46 -0500
commitc755e251357a0cee0679081f08c3f4ba797a8009 (patch)
treed69b67161bff0173ed4589db59dbf8f0766c0bb2 /fs/ext4/inline.c
parent670e9875eb14b112fa6a206a65c776a4fb347eb1 (diff)
downloadlinux-stericsson-c755e251357a0cee0679081f08c3f4ba797a8009.tar.gz
ext4: fix deadlock between inline_data and ext4_expand_extra_isize_ea()
The xattr_sem deadlock problems fixed in commit 2e81a4eeedca: "ext4: avoid deadlock when expanding inode size" didn't include the use of xattr_sem in fs/ext4/inline.c. With the addition of project quota which added a new extra inode field, this exposed deadlocks in the inline_data code similar to the ones fixed by 2e81a4eeedca. The deadlock can be reproduced via: dmesg -n 7 mke2fs -t ext4 -O inline_data -Fq -I 256 /dev/vdc 32768 mount -t ext4 -o debug_want_extra_isize=24 /dev/vdc /vdc mkdir /vdc/a umount /vdc mount -t ext4 /dev/vdc /vdc echo foo > /vdc/a/foo and looks like this: [ 11.158815] [ 11.160276] ============================================= [ 11.161960] [ INFO: possible recursive locking detected ] [ 11.161960] 4.10.0-rc3-00015-g011b30a8a3cf #160 Tainted: G W [ 11.161960] --------------------------------------------- [ 11.161960] bash/2519 is trying to acquire lock: [ 11.161960] (&ei->xattr_sem){++++..}, at: [<c1225a4b>] ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] [ 11.161960] but task is already holding lock: [ 11.161960] (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152 [ 11.161960] [ 11.161960] other info that might help us debug this: [ 11.161960] Possible unsafe locking scenario: [ 11.161960] [ 11.161960] CPU0 [ 11.161960] ---- [ 11.161960] lock(&ei->xattr_sem); [ 11.161960] lock(&ei->xattr_sem); [ 11.161960] [ 11.161960] *** DEADLOCK *** [ 11.161960] [ 11.161960] May be due to missing lock nesting notation [ 11.161960] [ 11.161960] 4 locks held by bash/2519: [ 11.161960] #0: (sb_writers#3){.+.+.+}, at: [<c11a2414>] mnt_want_write+0x1e/0x3e [ 11.161960] #1: (&type->i_mutex_dir_key){++++++}, at: [<c119508b>] path_openat+0x338/0x67a [ 11.161960] #2: (jbd2_handle){++++..}, at: [<c123314a>] start_this_handle+0x582/0x622 [ 11.161960] #3: (&ei->xattr_sem){++++..}, at: [<c1227941>] ext4_try_add_inline_entry+0x3a/0x152 [ 11.161960] [ 11.161960] stack backtrace: [ 11.161960] CPU: 0 PID: 2519 Comm: bash Tainted: G W 4.10.0-rc3-00015-g011b30a8a3cf #160 [ 11.161960] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1 04/01/2014 [ 11.161960] Call Trace: [ 11.161960] dump_stack+0x72/0xa3 [ 11.161960] __lock_acquire+0xb7c/0xcb9 [ 11.161960] ? kvm_clock_read+0x1f/0x29 [ 11.161960] ? __lock_is_held+0x36/0x66 [ 11.161960] ? __lock_is_held+0x36/0x66 [ 11.161960] lock_acquire+0x106/0x18a [ 11.161960] ? ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] down_write+0x39/0x72 [ 11.161960] ? ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] ext4_expand_extra_isize_ea+0x3d/0x4cd [ 11.161960] ? _raw_read_unlock+0x22/0x2c [ 11.161960] ? jbd2_journal_extend+0x1e2/0x262 [ 11.161960] ? __ext4_journal_get_write_access+0x3d/0x60 [ 11.161960] ext4_mark_inode_dirty+0x17d/0x26d [ 11.161960] ? ext4_add_dirent_to_inline.isra.12+0xa5/0xb2 [ 11.161960] ext4_add_dirent_to_inline.isra.12+0xa5/0xb2 [ 11.161960] ext4_try_add_inline_entry+0x69/0x152 [ 11.161960] ext4_add_entry+0xa3/0x848 [ 11.161960] ? __brelse+0x14/0x2f [ 11.161960] ? _raw_spin_unlock_irqrestore+0x44/0x4f [ 11.161960] ext4_add_nondir+0x17/0x5b [ 11.161960] ext4_create+0xcf/0x133 [ 11.161960] ? ext4_mknod+0x12f/0x12f [ 11.161960] lookup_open+0x39e/0x3fb [ 11.161960] ? __wake_up+0x1a/0x40 [ 11.161960] ? lock_acquire+0x11e/0x18a [ 11.161960] path_openat+0x35c/0x67a [ 11.161960] ? sched_clock_cpu+0xd7/0xf2 [ 11.161960] do_filp_open+0x36/0x7c [ 11.161960] ? _raw_spin_unlock+0x22/0x2c [ 11.161960] ? __alloc_fd+0x169/0x173 [ 11.161960] do_sys_open+0x59/0xcc [ 11.161960] SyS_open+0x1d/0x1f [ 11.161960] do_int80_syscall_32+0x4f/0x61 [ 11.161960] entry_INT80_32+0x2f/0x2f [ 11.161960] EIP: 0xb76ad469 [ 11.161960] EFLAGS: 00000286 CPU: 0 [ 11.161960] EAX: ffffffda EBX: 08168ac8 ECX: 00008241 EDX: 000001b6 [ 11.161960] ESI: b75e46bc EDI: b7755000 EBP: bfbdb108 ESP: bfbdafc0 [ 11.161960] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b Cc: stable@vger.kernel.org # 3.10 (requires 2e81a4eeedca as a prereq) Reported-by: George Spelvin <linux@sciencehorizons.net> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/inline.c')
-rw-r--r--fs/ext4/inline.c66
1 files changed, 30 insertions, 36 deletions
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 437df6a1a841..99a5312ced52 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -381,7 +381,7 @@ out:
static int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
unsigned int len)
{
- int ret, size;
+ int ret, size, no_expand;
struct ext4_inode_info *ei = EXT4_I(inode);
if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
@@ -391,15 +391,14 @@ static int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
if (size < len)
return -ENOSPC;
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
if (ei->i_inline_off)
ret = ext4_update_inline_data(handle, inode, len);
else
ret = ext4_create_inline_data(handle, inode, len);
- up_write(&EXT4_I(inode)->xattr_sem);
-
+ ext4_write_unlock_xattr(inode, &no_expand);
return ret;
}
@@ -533,7 +532,7 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
struct inode *inode,
unsigned flags)
{
- int ret, needed_blocks;
+ int ret, needed_blocks, no_expand;
handle_t *handle = NULL;
int retries = 0, sem_held = 0;
struct page *page = NULL;
@@ -573,7 +572,7 @@ retry:
goto out;
}
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
sem_held = 1;
/* If some one has already done this for us, just exit. */
if (!ext4_has_inline_data(inode)) {
@@ -610,7 +609,7 @@ retry:
put_page(page);
page = NULL;
ext4_orphan_add(handle, inode);
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
sem_held = 0;
ext4_journal_stop(handle);
handle = NULL;
@@ -636,7 +635,7 @@ out:
put_page(page);
}
if (sem_held)
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
if (handle)
ext4_journal_stop(handle);
brelse(iloc.bh);
@@ -729,7 +728,7 @@ convert:
int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
unsigned copied, struct page *page)
{
- int ret;
+ int ret, no_expand;
void *kaddr;
struct ext4_iloc iloc;
@@ -747,7 +746,7 @@ int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
goto out;
}
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
BUG_ON(!ext4_has_inline_data(inode));
kaddr = kmap_atomic(page);
@@ -757,7 +756,7 @@ int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
/* clear page dirty so that writepages wouldn't work for us. */
ClearPageDirty(page);
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
brelse(iloc.bh);
out:
return copied;
@@ -768,7 +767,7 @@ ext4_journalled_write_inline_data(struct inode *inode,
unsigned len,
struct page *page)
{
- int ret;
+ int ret, no_expand;
void *kaddr;
struct ext4_iloc iloc;
@@ -778,11 +777,11 @@ ext4_journalled_write_inline_data(struct inode *inode,
return NULL;
}
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
kaddr = kmap_atomic(page);
ext4_write_inline_data(inode, &iloc, kaddr, 0, len);
kunmap_atomic(kaddr);
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
return iloc.bh;
}
@@ -1259,7 +1258,7 @@ out:
int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
struct inode *dir, struct inode *inode)
{
- int ret, inline_size;
+ int ret, inline_size, no_expand;
void *inline_start;
struct ext4_iloc iloc;
@@ -1267,7 +1266,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
if (ret)
return ret;
- down_write(&EXT4_I(dir)->xattr_sem);
+ ext4_write_lock_xattr(dir, &no_expand);
if (!ext4_has_inline_data(dir))
goto out;
@@ -1313,7 +1312,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
out:
ext4_mark_inode_dirty(handle, dir);
- up_write(&EXT4_I(dir)->xattr_sem);
+ ext4_write_unlock_xattr(dir, &no_expand);
brelse(iloc.bh);
return ret;
}
@@ -1673,7 +1672,7 @@ int ext4_delete_inline_entry(handle_t *handle,
struct buffer_head *bh,
int *has_inline_data)
{
- int err, inline_size;
+ int err, inline_size, no_expand;
struct ext4_iloc iloc;
void *inline_start;
@@ -1681,7 +1680,7 @@ int ext4_delete_inline_entry(handle_t *handle,
if (err)
return err;
- down_write(&EXT4_I(dir)->xattr_sem);
+ ext4_write_lock_xattr(dir, &no_expand);
if (!ext4_has_inline_data(dir)) {
*has_inline_data = 0;
goto out;
@@ -1715,7 +1714,7 @@ int ext4_delete_inline_entry(handle_t *handle,
ext4_show_inline_dir(dir, iloc.bh, inline_start, inline_size);
out:
- up_write(&EXT4_I(dir)->xattr_sem);
+ ext4_write_unlock_xattr(dir, &no_expand);
brelse(iloc.bh);
if (err != -ENOENT)
ext4_std_error(dir->i_sb, err);
@@ -1814,11 +1813,11 @@ out:
int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
{
- int ret;
+ int ret, no_expand;
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
ret = ext4_destroy_inline_data_nolock(handle, inode);
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
return ret;
}
@@ -1903,7 +1902,7 @@ out:
void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
{
handle_t *handle;
- int inline_size, value_len, needed_blocks;
+ int inline_size, value_len, needed_blocks, no_expand;
size_t i_size;
void *value = NULL;
struct ext4_xattr_ibody_find is = {
@@ -1920,7 +1919,7 @@ void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
if (IS_ERR(handle))
return;
- down_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_lock_xattr(inode, &no_expand);
if (!ext4_has_inline_data(inode)) {
*has_inline = 0;
ext4_journal_stop(handle);
@@ -1978,7 +1977,7 @@ out_error:
up_write(&EXT4_I(inode)->i_data_sem);
out:
brelse(is.iloc.bh);
- up_write(&EXT4_I(inode)->xattr_sem);
+ ext4_write_unlock_xattr(inode, &no_expand);
kfree(value);
if (inode->i_nlink)
ext4_orphan_del(handle, inode);
@@ -1994,7 +1993,7 @@ out:
int ext4_convert_inline_data(struct inode *inode)
{
- int error, needed_blocks;
+ int error, needed_blocks, no_expand;
handle_t *handle;
struct ext4_iloc iloc;
@@ -2016,15 +2015,10 @@ int ext4_convert_inline_data(struct inode *inode)
goto out_free;
}
- down_write(&EXT4_I(inode)->xattr_sem);
- if (!ext4_has_inline_data(inode)) {
- up_write(&EXT4_I(inode)->xattr_sem);
- goto out;
- }
-
- error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
- up_write(&EXT4_I(inode)->xattr_sem);
-out:
+ ext4_write_lock_xattr(inode, &no_expand);
+ if (ext4_has_inline_data(inode))
+ error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
+ ext4_write_unlock_xattr(inode, &no_expand);
ext4_journal_stop(handle);
out_free:
brelse(iloc.bh);