From: Trond Myklebust trond.myklebust@hammerspace.com
[ Upstream commit 108bb4afd351d65826648a47f11fa3104e250d9b ]
If the attempt to instantiate the mirror's layout DS pointer failed, then that pointer may hold a value of type ERR_PTR(), so we need to check that before we dereference it.
Fixes: 65990d1afbd2d ("pNFS/flexfiles: Fix a deadlock on LAYOUTGET") Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/flexfilelayout/flexfilelayout.h | 32 +++++++++++++++----------- 1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/fs/nfs/flexfilelayout/flexfilelayout.h b/fs/nfs/flexfilelayout/flexfilelayout.h index d6515f1584f3c..d78ec99b6c4ca 100644 --- a/fs/nfs/flexfilelayout/flexfilelayout.h +++ b/fs/nfs/flexfilelayout/flexfilelayout.h @@ -131,16 +131,6 @@ FF_LAYOUT_LSEG(struct pnfs_layout_segment *lseg) generic_hdr); }
-static inline struct nfs4_deviceid_node * -FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx) -{ - if (idx >= FF_LAYOUT_LSEG(lseg)->mirror_array_cnt || - FF_LAYOUT_LSEG(lseg)->mirror_array[idx] == NULL || - FF_LAYOUT_LSEG(lseg)->mirror_array[idx]->mirror_ds == NULL) - return NULL; - return &FF_LAYOUT_LSEG(lseg)->mirror_array[idx]->mirror_ds->id_node; -} - static inline struct nfs4_ff_layout_ds * FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node) { @@ -150,9 +140,25 @@ FF_LAYOUT_MIRROR_DS(struct nfs4_deviceid_node *node) static inline struct nfs4_ff_layout_mirror * FF_LAYOUT_COMP(struct pnfs_layout_segment *lseg, u32 idx) { - if (idx >= FF_LAYOUT_LSEG(lseg)->mirror_array_cnt) - return NULL; - return FF_LAYOUT_LSEG(lseg)->mirror_array[idx]; + struct nfs4_ff_layout_segment *fls = FF_LAYOUT_LSEG(lseg); + + if (idx < fls->mirror_array_cnt) + return fls->mirror_array[idx]; + return NULL; +} + +static inline struct nfs4_deviceid_node * +FF_LAYOUT_DEVID_NODE(struct pnfs_layout_segment *lseg, u32 idx) +{ + struct nfs4_ff_layout_mirror *mirror = FF_LAYOUT_COMP(lseg, idx); + + if (mirror != NULL) { + struct nfs4_ff_layout_ds *mirror_ds = mirror->mirror_ds; + + if (!IS_ERR_OR_NULL(mirror_ds)) + return &mirror_ds->id_node; + } + return NULL; }
static inline u32