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| author | Benjamin Marzinski <bmarzins@redhat.com> | 2012-11-07 07:38:06 +0100 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2012-11-07 10:43:03 +0100 |
| commit | 96e5d1d3adf56f1c7eeb07258f6a1a0a7ae9c489 (patch) | |
| tree | ca5a7f4cf7508bc287af7b35b1d75e71d11f765b /fs/gfs2/trans.c | |
| parent | GFS2: Don't call file_accessed() with a shared glock (diff) | |
| download | linux-96e5d1d3adf56f1c7eeb07258f6a1a0a7ae9c489.tar.xz linux-96e5d1d3adf56f1c7eeb07258f6a1a0a7ae9c489.zip | |
GFS2: Test bufdata with buffer locked and gfs2_log_lock held
In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then assuming it would
stay attached for the rest of the function. However, without either the log
lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any
time. This patch moves the locking before the test. If there isn't a bd
already attached, gfs2 can safely allocate one and attach it before locking.
There is no way that the newly allocated bd could be on the ail list,
and thus no way for __gfs2_ail_flush() to detach it.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/trans.c')
| -rw-r--r-- | fs/gfs2/trans.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c index adbd27875ef9..413627072f36 100644 --- a/fs/gfs2/trans.c +++ b/fs/gfs2/trans.c @@ -155,14 +155,22 @@ void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta) struct gfs2_sbd *sdp = gl->gl_sbd; struct gfs2_bufdata *bd; + lock_buffer(bh); + gfs2_log_lock(sdp); bd = bh->b_private; if (bd) gfs2_assert(sdp, bd->bd_gl == gl); else { + gfs2_log_unlock(sdp); + unlock_buffer(bh); gfs2_attach_bufdata(gl, bh, meta); bd = bh->b_private; + lock_buffer(bh); + gfs2_log_lock(sdp); } lops_add(sdp, bd); + gfs2_log_unlock(sdp); + unlock_buffer(bh); } void gfs2_trans_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd) |