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ext4: Properly count journal credits for long symlinks

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Commit df5e6223407e ("ext4: fix deadlock in ext4_symlink() in ENOSPC
conditions") recalculated the number of credits needed for a long
symlink, in the process of splitting it into two transactions.  However,
the first credit calculation under-counted because if selinux is
enabled, credits are needed to create the selinux xattr as well.

Overrunning the reservation will result in an OOPS in
jbd2_journal_dirty_metadata() due to this assert:

  J_ASSERT_JH(jh, handle->h_buffer_credits > 0);

Fix this by increasing the reservation size.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Sandeen 2011-08-11 09:54:31 -05:00 committed by Linus Torvalds
parent d2db60df1e
commit 8c20871998
1 changed files with 4 additions and 2 deletions
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6
fs/ext4/namei.c
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@ -2253,9 +2253,11 @@ static int ext4_symlink(struct inode *dir,
/*
* For non-fast symlinks, we just allocate inode and put it on
* orphan list in the first transaction => we need bitmap,
* group descriptor, sb, inode block, quota blocks.
* group descriptor, sb, inode block, quota blocks, and
* possibly selinux xattr blocks.
*/
credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb);
credits = 4 + EXT4_MAXQUOTAS_INIT_BLOCKS(dir->i_sb) +
EXT4_XATTR_TRANS_BLOCKS;
} else {
/*
* Fast symlink. We have to add entry to directory