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| author | Steven Whitehouse <swhiteho@redhat.com> | 2006-11-08 10:26:54 -0500 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2006-11-30 10:34:43 -0500 |
| commit | 2ca99501fa5422e84f18333918a503433449e2b5 (patch) | |
| tree | 46bdb25c3be5bdc4e4c80b30a99dd3811f2ee1c0 | |
| parent | c594d8866460a2710c436839d79f334a0714a2a7 (diff) | |
| download | op-kernel-dev-2ca99501fa5422e84f18333918a503433449e2b5.zip op-kernel-dev-2ca99501fa5422e84f18333918a503433449e2b5.tar.gz | |
[GFS2] Fix page lock/glock deadlock
This fixes a race between the glock and the page lock encountered
during truncate in gfs2_readpage and gfs2_prepare_write. The gfs2_readpages
function doesn't need the same fix since it only uses a try lock anyway, so
it will fail back to gfs2_readpage in the case of a potential deadlock.
This bug was spotted by Russell Cattelan.
Cc: Russell Cattelan <cattelan@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
| -rw-r--r-- | fs/gfs2/glock.h | 1 | ||||
| -rw-r--r-- | fs/gfs2/ops_address.c | 13 |
2 files changed, 9 insertions, 5 deletions
diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h index b985627..a331bf8 100644 --- a/fs/gfs2/glock.h +++ b/fs/gfs2/glock.h @@ -27,7 +27,6 @@ #define GL_ATIME 0x00000200 #define GL_NOCACHE 0x00000400 #define GL_NOCANCEL 0x00001000 -#define GL_AOP 0x00004000 #define GLR_TRYFAILED 13 #define GLR_CANCELED 14 diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c index 5c3962c..3822189 100644 --- a/fs/gfs2/ops_address.c +++ b/fs/gfs2/ops_address.c @@ -230,7 +230,7 @@ static int gfs2_readpage(struct file *file, struct page *page) /* gfs2_sharewrite_nopage has grabbed the ip->i_gl already */ goto skip_lock; } - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|GL_AOP, &gh); + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, GL_ATIME|LM_FLAG_TRY_1CB, &gh); do_unlock = 1; error = gfs2_glock_nq_m_atime(1, &gh); if (unlikely(error)) @@ -254,6 +254,8 @@ skip_lock: out: return error; out_unlock: + if (error == GLR_TRYFAILED) + error = AOP_TRUNCATED_PAGE; unlock_page(page); if (do_unlock) gfs2_holder_uninit(&gh); @@ -293,7 +295,7 @@ static int gfs2_readpages(struct file *file, struct address_space *mapping, goto skip_lock; } gfs2_holder_init(ip->i_gl, LM_ST_SHARED, - LM_FLAG_TRY_1CB|GL_ATIME|GL_AOP, &gh); + LM_FLAG_TRY_1CB|GL_ATIME, &gh); do_unlock = 1; ret = gfs2_glock_nq_m_atime(1, &gh); if (ret == GLR_TRYFAILED) @@ -366,10 +368,13 @@ static int gfs2_prepare_write(struct file *file, struct page *page, unsigned int write_len = to - from; - gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|GL_AOP, &ip->i_gh); + gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME|LM_FLAG_TRY_1CB, &ip->i_gh); error = gfs2_glock_nq_m_atime(1, &ip->i_gh); - if (error) + if (unlikely(error)) { + if (error == GLR_TRYFAILED) + error = AOP_TRUNCATED_PAGE; goto out_uninit; + } gfs2_write_calc_reserv(ip, write_len, &data_blocks, &ind_blocks); |
