Re: [PATCH] JBD: use GFP_NOFS in kmalloc
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2007-09-19 21:34:29
Also in:
linux-fsdevel, lkml
On Wed, 19 Sep 2007 12:22:09 -0700 Mingming Cao [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Convert the GFP_KERNEL flag used in JBD/JBD2 to GFP_NOFS, consistent with the rest of kmalloc flag used in the JBD/JBD2 layer. Signed-off-by: Mingming Cao <redacted> --- fs/jbd/journal.c | 6 +++--- fs/jbd/revoke.c | 8 ++++---- fs/jbd2/journal.c | 6 +++--- fs/jbd2/revoke.c | 8 ++++---- 4 files changed, 14 insertions(+), 14 deletions(-) Index: linux-2.6.23-rc6/fs/jbd/journal.c ===================================================================--- linux-2.6.23-rc6.orig/fs/jbd/journal.c 2007-09-19 11:51:10.000000000 -0700 +++ linux-2.6.23-rc6/fs/jbd/journal.c 2007-09-19 11:51:57.000000000 -0700@@ -653,7 +653,7 @@ static journal_t * journal_init_common ( journal_t *journal; int err; - journal = kmalloc(sizeof(*journal), GFP_KERNEL); + journal = kmalloc(sizeof(*journal), GFP_NOFS); if (!journal) goto fail; memset(journal, 0, sizeof(*journal));@@ -723,7 +723,7 @@ journal_t * journal_init_dev(struct bloc journal->j_blocksize = blocksize; n = journal->j_blocksize / sizeof(journal_block_tag_t); journal->j_wbufsize = n; - journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); + journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_NOFS); if (!journal->j_wbuf) { printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", __FUNCTION__);@@ -777,7 +777,7 @@ journal_t * journal_init_inode (struct i /* journal descriptor can store up to n blocks -bzzz */ n = journal->j_blocksize / sizeof(journal_block_tag_t); journal->j_wbufsize = n; - journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL); + journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_NOFS); if (!journal->j_wbuf) { printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n", __FUNCTION__);Index: linux-2.6.23-rc6/fs/jbd/revoke.c ===================================================================--- linux-2.6.23-rc6.orig/fs/jbd/revoke.c 2007-09-19 11:51:30.000000000 -0700 +++ linux-2.6.23-rc6/fs/jbd/revoke.c 2007-09-19 11:52:34.000000000 -0700@@ -206,7 +206,7 @@ int journal_init_revoke(journal_t *journ while((tmp >>= 1UL) != 0UL) shift++; - journal->j_revoke_table[0] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL); + journal->j_revoke_table[0] = kmem_cache_alloc(revoke_table_cache, GFP_NOFS); if (!journal->j_revoke_table[0]) return -ENOMEM; journal->j_revoke = journal->j_revoke_table[0];@@ -219,7 +219,7 @@ int journal_init_revoke(journal_t *journ journal->j_revoke->hash_shift = shift; journal->j_revoke->hash_table = - kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); + kmalloc(hash_size * sizeof(struct list_head), GFP_NOFS); if (!journal->j_revoke->hash_table) { kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]); journal->j_revoke = NULL;@@ -229,7 +229,7 @@ int journal_init_revoke(journal_t *journ for (tmp = 0; tmp < hash_size; tmp++) INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]); - journal->j_revoke_table[1] = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL); + journal->j_revoke_table[1] = kmem_cache_alloc(revoke_table_cache, GFP_NOFS); if (!journal->j_revoke_table[1]) { kfree(journal->j_revoke_table[0]->hash_table); kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]);@@ -246,7 +246,7 @@ int journal_init_revoke(journal_t *journ journal->j_revoke->hash_shift = shift; journal->j_revoke->hash_table = - kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); + kmalloc(hash_size * sizeof(struct list_head), GFP_NOFS); if (!journal->j_revoke->hash_table) { kfree(journal->j_revoke_table[0]->hash_table); kmem_cache_free(revoke_table_cache, journal->j_revoke_table[0]);
These were all OK using GFP_KERNEL. GFP_NOFS should only be used when the caller is holding some fs locks which might cause a deadlock if that caller reentered the fs in ->writepage (and maybe put_inode and such). That isn't the case in any of the above code, which is all mount time stuff (I think). ext3/4 should be using GFP_NOFS when the caller has a transaction open, has a page locked, is holding i_mutex, etc.