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 byzero-colors2e81a4eeed. 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 (requires2e81a4eeedas a prereq) Reported-by: George Spelvin <linux@sciencehorizons.net> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Theodore Ts'o
parent
670e9875eb
commit
c755e25135
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@ -381,7 +381,7 @@ out:
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static int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
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unsigned int len)
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{
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int ret, size;
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int ret, size, no_expand;
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struct ext4_inode_info *ei = EXT4_I(inode);
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if (!ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
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@ -391,15 +391,14 @@ static int ext4_prepare_inline_data(handle_t *handle, struct inode *inode,
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if (size < len)
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return -ENOSPC;
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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if (ei->i_inline_off)
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ret = ext4_update_inline_data(handle, inode, len);
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else
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ret = ext4_create_inline_data(handle, inode, len);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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return ret;
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}
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@ -533,7 +532,7 @@ static int ext4_convert_inline_data_to_extent(struct address_space *mapping,
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struct inode *inode,
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unsigned flags)
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{
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int ret, needed_blocks;
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int ret, needed_blocks, no_expand;
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handle_t *handle = NULL;
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int retries = 0, sem_held = 0;
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struct page *page = NULL;
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@ -573,7 +572,7 @@ retry:
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goto out;
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}
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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sem_held = 1;
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/* If some one has already done this for us, just exit. */
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if (!ext4_has_inline_data(inode)) {
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@ -610,7 +609,7 @@ retry:
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put_page(page);
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page = NULL;
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ext4_orphan_add(handle, inode);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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sem_held = 0;
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ext4_journal_stop(handle);
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handle = NULL;
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@ -636,7 +635,7 @@ out:
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put_page(page);
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}
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if (sem_held)
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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if (handle)
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ext4_journal_stop(handle);
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brelse(iloc.bh);
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@ -729,7 +728,7 @@ convert:
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int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
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unsigned copied, struct page *page)
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{
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int ret;
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int ret, no_expand;
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void *kaddr;
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struct ext4_iloc iloc;
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@ -747,7 +746,7 @@ int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
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goto out;
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}
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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BUG_ON(!ext4_has_inline_data(inode));
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kaddr = kmap_atomic(page);
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@ -757,7 +756,7 @@ int ext4_write_inline_data_end(struct inode *inode, loff_t pos, unsigned len,
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/* clear page dirty so that writepages wouldn't work for us. */
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ClearPageDirty(page);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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brelse(iloc.bh);
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out:
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return copied;
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@ -768,7 +767,7 @@ ext4_journalled_write_inline_data(struct inode *inode,
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unsigned len,
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struct page *page)
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{
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int ret;
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int ret, no_expand;
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void *kaddr;
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struct ext4_iloc iloc;
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@ -778,11 +777,11 @@ ext4_journalled_write_inline_data(struct inode *inode,
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return NULL;
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}
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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kaddr = kmap_atomic(page);
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ext4_write_inline_data(inode, &iloc, kaddr, 0, len);
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kunmap_atomic(kaddr);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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return iloc.bh;
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}
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@ -1259,7 +1258,7 @@ out:
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int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
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struct inode *dir, struct inode *inode)
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{
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int ret, inline_size;
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int ret, inline_size, no_expand;
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void *inline_start;
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struct ext4_iloc iloc;
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@ -1267,7 +1266,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
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if (ret)
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return ret;
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down_write(&EXT4_I(dir)->xattr_sem);
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ext4_write_lock_xattr(dir, &no_expand);
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if (!ext4_has_inline_data(dir))
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goto out;
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@ -1313,7 +1312,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
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out:
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ext4_mark_inode_dirty(handle, dir);
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up_write(&EXT4_I(dir)->xattr_sem);
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ext4_write_unlock_xattr(dir, &no_expand);
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brelse(iloc.bh);
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return ret;
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}
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@ -1673,7 +1672,7 @@ int ext4_delete_inline_entry(handle_t *handle,
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struct buffer_head *bh,
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int *has_inline_data)
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{
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int err, inline_size;
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int err, inline_size, no_expand;
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struct ext4_iloc iloc;
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void *inline_start;
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@ -1681,7 +1680,7 @@ int ext4_delete_inline_entry(handle_t *handle,
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if (err)
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return err;
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down_write(&EXT4_I(dir)->xattr_sem);
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ext4_write_lock_xattr(dir, &no_expand);
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if (!ext4_has_inline_data(dir)) {
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*has_inline_data = 0;
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goto out;
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@ -1715,7 +1714,7 @@ int ext4_delete_inline_entry(handle_t *handle,
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ext4_show_inline_dir(dir, iloc.bh, inline_start, inline_size);
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out:
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up_write(&EXT4_I(dir)->xattr_sem);
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ext4_write_unlock_xattr(dir, &no_expand);
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brelse(iloc.bh);
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if (err != -ENOENT)
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ext4_std_error(dir->i_sb, err);
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@ -1814,11 +1813,11 @@ out:
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int ext4_destroy_inline_data(handle_t *handle, struct inode *inode)
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{
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int ret;
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int ret, no_expand;
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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ret = ext4_destroy_inline_data_nolock(handle, inode);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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return ret;
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}
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@ -1903,7 +1902,7 @@ out:
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void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
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{
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handle_t *handle;
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int inline_size, value_len, needed_blocks;
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int inline_size, value_len, needed_blocks, no_expand;
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size_t i_size;
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void *value = NULL;
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struct ext4_xattr_ibody_find is = {
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@ -1920,7 +1919,7 @@ void ext4_inline_data_truncate(struct inode *inode, int *has_inline)
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if (IS_ERR(handle))
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return;
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down_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_lock_xattr(inode, &no_expand);
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if (!ext4_has_inline_data(inode)) {
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*has_inline = 0;
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ext4_journal_stop(handle);
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@ -1978,7 +1977,7 @@ out_error:
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up_write(&EXT4_I(inode)->i_data_sem);
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out:
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brelse(is.iloc.bh);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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kfree(value);
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if (inode->i_nlink)
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ext4_orphan_del(handle, inode);
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@ -1994,7 +1993,7 @@ out:
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int ext4_convert_inline_data(struct inode *inode)
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{
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int error, needed_blocks;
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int error, needed_blocks, no_expand;
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handle_t *handle;
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struct ext4_iloc iloc;
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@ -2016,15 +2015,10 @@ int ext4_convert_inline_data(struct inode *inode)
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goto out_free;
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}
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down_write(&EXT4_I(inode)->xattr_sem);
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if (!ext4_has_inline_data(inode)) {
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up_write(&EXT4_I(inode)->xattr_sem);
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goto out;
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}
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error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
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up_write(&EXT4_I(inode)->xattr_sem);
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out:
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ext4_write_lock_xattr(inode, &no_expand);
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if (ext4_has_inline_data(inode))
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error = ext4_convert_inline_data_nolock(handle, inode, &iloc);
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ext4_write_unlock_xattr(inode, &no_expand);
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ext4_journal_stop(handle);
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out_free:
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brelse(iloc.bh);
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@ -1188,16 +1188,14 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
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struct ext4_xattr_block_find bs = {
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.s = { .not_found = -ENODATA, },
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};
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unsigned long no_expand;
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int no_expand;
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int error;
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if (!name)
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return -EINVAL;
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if (strlen(name) > 255)
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return -ERANGE;
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down_write(&EXT4_I(inode)->xattr_sem);
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no_expand = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
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ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
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ext4_write_lock_xattr(inode, &no_expand);
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error = ext4_reserve_inode_write(handle, inode, &is.iloc);
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if (error)
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@ -1264,7 +1262,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
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ext4_xattr_update_super_block(handle, inode->i_sb);
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inode->i_ctime = current_time(inode);
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if (!value)
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ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
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no_expand = 0;
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error = ext4_mark_iloc_dirty(handle, inode, &is.iloc);
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/*
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* The bh is consumed by ext4_mark_iloc_dirty, even with
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@ -1278,9 +1276,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
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cleanup:
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brelse(is.iloc.bh);
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brelse(bs.bh);
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if (no_expand == 0)
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ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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return error;
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}
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@ -1497,12 +1493,11 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
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int error = 0, tried_min_extra_isize = 0;
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int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
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int isize_diff; /* How much do we need to grow i_extra_isize */
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int no_expand;
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if (ext4_write_trylock_xattr(inode, &no_expand) == 0)
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return 0;
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down_write(&EXT4_I(inode)->xattr_sem);
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/*
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* Set EXT4_STATE_NO_EXPAND to avoid recursion when marking inode dirty
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*/
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ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
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retry:
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isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
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if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
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@ -1584,17 +1579,16 @@ shift:
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EXT4_I(inode)->i_extra_isize = new_extra_isize;
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brelse(bh);
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out:
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ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
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up_write(&EXT4_I(inode)->xattr_sem);
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ext4_write_unlock_xattr(inode, &no_expand);
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return 0;
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cleanup:
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brelse(bh);
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/*
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* We deliberately leave EXT4_STATE_NO_EXPAND set here since inode
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* size expansion failed.
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* Inode size expansion failed; don't try again
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*/
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up_write(&EXT4_I(inode)->xattr_sem);
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no_expand = 1;
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ext4_write_unlock_xattr(inode, &no_expand);
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return error;
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}
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@ -102,6 +102,38 @@ extern const struct xattr_handler ext4_xattr_security_handler;
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#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
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||||
|
||||
/*
|
||||
* The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
|
||||
* The first is to signal that there the inline xattrs and data are
|
||||
* taking up so much space that we might as well not keep trying to
|
||||
* expand it. The second is that xattr_sem is taken for writing, so
|
||||
* we shouldn't try to recurse into the inode expansion. For this
|
||||
* second case, we need to make sure that we take save and restore the
|
||||
* NO_EXPAND state flag appropriately.
|
||||
*/
|
||||
static inline void ext4_write_lock_xattr(struct inode *inode, int *save)
|
||||
{
|
||||
down_write(&EXT4_I(inode)->xattr_sem);
|
||||
*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
|
||||
ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
|
||||
}
|
||||
|
||||
static inline int ext4_write_trylock_xattr(struct inode *inode, int *save)
|
||||
{
|
||||
if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
|
||||
return 0;
|
||||
*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
|
||||
ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
|
||||
return 1;
|
||||
}
|
||||
|
||||
static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
|
||||
{
|
||||
if (*save == 0)
|
||||
ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
|
||||
up_write(&EXT4_I(inode)->xattr_sem);
|
||||
}
|
||||
|
||||
extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
|
||||
|
||||
extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
|
||||
|
|
|
|||
Loading…
Reference in New Issue