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| author | Matthew L. Creech <mlcreech@gmail.com> | 2011-03-04 17:55:02 -0500 |
|---|---|---|
| committer | Artem Bityutskiy <Artem.Bityutskiy@nokia.com> | 2011-03-11 10:52:07 +0200 |
| commit | d882962f6af2b484b62a7fb05ef959e1bf355fc4 (patch) | |
| tree | 040a303908493e5edca3fe5c7aeecab2912bd3b0 /fs/ubifs/super.c | |
| parent | 2765df7da540687c4d57ca840182122f074c5b9c (diff) | |
| download | linux-d882962f6af2b484b62a7fb05ef959e1bf355fc4.tar.bz2 | |
UBIFS: handle allocation failures in UBIFS write path
Running kernel 2.6.37, my PPC-based device occasionally gets an
order-2 allocation failure in UBIFS, which causes the root FS to
become unwritable:
kswapd0: page allocation failure. order:2, mode:0x4050
Call Trace:
[c787dc30] [c00085b8] show_stack+0x7c/0x194 (unreliable)
[c787dc70] [c0061aec] __alloc_pages_nodemask+0x4f0/0x57c
[c787dd00] [c0061b98] __get_free_pages+0x20/0x50
[c787dd10] [c00e4f88] ubifs_jnl_write_data+0x54/0x200
[c787dd50] [c00e82d4] do_writepage+0x94/0x198
[c787dd90] [c00675e4] shrink_page_list+0x40c/0x77c
[c787de40] [c0067de0] shrink_inactive_list+0x1e0/0x370
[c787de90] [c0068224] shrink_zone+0x2b4/0x2b8
[c787df00] [c0068854] kswapd+0x408/0x5d4
[c787dfb0] [c0037bcc] kthread+0x80/0x84
[c787dff0] [c000ef44] kernel_thread+0x4c/0x68
Similar problems were encountered last April by Tomasz Stanislawski:
http://patchwork.ozlabs.org/patch/50965/
This patch implements Artem's suggested fix: fall back to a
mutex-protected static buffer, allocated at mount time. I tested it
by forcing execution down the failure path, and didn't see any ill
effects.
Artem: massaged the patch a little, improved it so that we'd not
allocate the write reserve buffer when we are in R/O mode.
Signed-off-by: Matthew L. Creech <mlcreech@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Diffstat (limited to 'fs/ubifs/super.c')
| -rw-r--r-- | fs/ubifs/super.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index d4b4cb4596e2..e360c7a71f9e 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -1213,6 +1213,13 @@ static int mount_ubifs(struct ubifs_info *c) if (c->bulk_read == 1) bu_init(c); + if (!c->ro_mount) { + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, + GFP_KERNEL); + if (!c->write_reserve_buf) + goto out_free; + } + c->mounting = 1; err = ubifs_read_superblock(c); @@ -1482,6 +1489,7 @@ out_wbufs: out_cbuf: kfree(c->cbuf); out_free: + kfree(c->write_reserve_buf); kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); @@ -1520,6 +1528,7 @@ static void ubifs_umount(struct ubifs_info *c) kfree(c->cbuf); kfree(c->rcvrd_mst_node); kfree(c->mst_node); + kfree(c->write_reserve_buf); kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); @@ -1605,6 +1614,10 @@ static int ubifs_remount_rw(struct ubifs_info *c) goto out; } + c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL); + if (!c->write_reserve_buf) + goto out; + err = ubifs_lpt_init(c, 0, 1); if (err) goto out; @@ -1669,6 +1682,8 @@ out: c->bgt = NULL; } free_wbufs(c); + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); @@ -1712,6 +1727,8 @@ static void ubifs_remount_ro(struct ubifs_info *c) free_wbufs(c); vfree(c->orph_buf); c->orph_buf = NULL; + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); @@ -1942,6 +1959,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) mutex_init(&c->mst_mutex); mutex_init(&c->umount_mutex); mutex_init(&c->bu_mutex); + mutex_init(&c->write_reserve_mutex); init_waitqueue_head(&c->cmt_wq); c->buds = RB_ROOT; c->old_idx = RB_ROOT; |