Messages in this thread Patch in this message | | | From | Ingo Oeser <> | Subject | Re: [PATCH REVIEW] udf: Fix lock inversion between iprune_mutex and alloc_mutex | Date | Thu, 14 Aug 2008 20:48:10 +0200 |
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Hi Jan,
On Thursday 14 August 2008, Jan Kara wrote: > A memory allocation inside alloc_mutex must not recurse back > into the filesystem itself because that leads to lock inversion > between iprune_mutex and alloc_mutex (and thus to deadlocks - see > traces below). Make allocations inside alloc_mutex use GFP_NOFS > to avoid this problem.
What about moving the allocation before taking the mutex? That way, we even reduce the lock contention and simplify the failure path.
Signed-off-by: Ingo Oeser <ioe-lkml@rameria.de>
diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c index eb9cfa2..76446eb 100644 --- a/fs/udf/ialloc.c +++ b/fs/udf/ialloc.c @@ -90,6 +90,25 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) return NULL; } + if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) { + iinfo->i_efe = 1; + if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev) + sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE; + iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - + sizeof(struct extendedFileEntry), + GFP_KERNEL); + } else { + iinfo->i_efe = 0; + iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - + sizeof(struct fileEntry), + GFP_KERNEL); + } + if (!iinfo->i_ext.i_data) { + iput(inode); + *err = -ENOMEM; + return NULL; + } + mutex_lock(&sbi->s_alloc_mutex); if (sbi->s_lvid_bh) { struct logicalVolIntegrityDesc *lvid = @@ -129,25 +148,6 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) iinfo->i_lenEAttr = 0; iinfo->i_lenAlloc = 0; iinfo->i_use = 0; - if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) { - iinfo->i_efe = 1; - if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev) - sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE; - iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - - sizeof(struct extendedFileEntry), - GFP_KERNEL); - } else { - iinfo->i_efe = 0; - iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - - sizeof(struct fileEntry), - GFP_KERNEL); - } - if (!iinfo->i_ext.i_data) { - iput(inode); - *err = -ENOMEM; - mutex_unlock(&sbi->s_alloc_mutex); - return NULL; - } if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_AD_IN_ICB)) iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB; else if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
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