| Message ID | 20200902035715.16414-1-gandalf@winds.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tmpfs: Restore functionality of nr_inodes=0 | expand |
On Tue, 1 Sep 2020, Byron Stanoszek wrote: > Commit e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") made changes to > shmem_reserve_inode() in mm/shmem.c, however the original test for > (sbinfo->max_inodes) got dropped. This causes mounting tmpfs with option > nr_inodes=0 to fail: > > # mount -ttmpfs -onr_inodes=0 none /ext0 > mount: /ext0: mount(2) system call failed: Cannot allocate memory. > > This patch restores the nr_inodes=0 functionality. > > Fixes: e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") > Cc: Chris Down <chris@chrisdown.name> > Signed-off-by: Byron Stanoszek <gandalf@winds.org> Yikes, thank you Byron, very bad of me not to have spotted that: Acked-by: Hugh Dickins <hughd@google.com> I've taken a quick look to see how I missed it: yes, I'd compared against my own tree, knew I had to come back here sometime to replace the SB_KERNMOUNT test by a max_inodes test like I had, to restore the performance of nr_inodes=0; but thought the SB_KERNMOUNT test was good enough for now - without realizing the effect on the code below it. The error does seem to be localized just to this block, yes. Many thanks. > --- > mm/shmem.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 271548ca20f3..8e2b35ba93ad 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -279,11 +279,13 @@ static int shmem_reserve_inode(struct super_block *sb, ino_t *inop) > > if (!(sb->s_flags & SB_KERNMOUNT)) { > spin_lock(&sbinfo->stat_lock); > - if (!sbinfo->free_inodes) { > - spin_unlock(&sbinfo->stat_lock); > - return -ENOSPC; > + if (sbinfo->max_inodes) { > + if (!sbinfo->free_inodes) { > + spin_unlock(&sbinfo->stat_lock); > + return -ENOSPC; > + } > + sbinfo->free_inodes--; > } > - sbinfo->free_inodes--; > if (inop) { > ino = sbinfo->next_ino++; > if (unlikely(is_zero_ino(ino))) > -- > 2.28.0
Byron Stanoszek writes: >Commit e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") made changes to >shmem_reserve_inode() in mm/shmem.c, however the original test for >(sbinfo->max_inodes) got dropped. This causes mounting tmpfs with option >nr_inodes=0 to fail: > > # mount -ttmpfs -onr_inodes=0 none /ext0 > mount: /ext0: mount(2) system call failed: Cannot allocate memory. > >This patch restores the nr_inodes=0 functionality. > >Fixes: e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") >Cc: Chris Down <chris@chrisdown.name> >Signed-off-by: Byron Stanoszek <gandalf@winds.org> Acked-by: Chris Down <chris@chrisdown.name> Thanks, good catch.
diff --git a/mm/shmem.c b/mm/shmem.c index 271548ca20f3..8e2b35ba93ad 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -279,11 +279,13 @@ static int shmem_reserve_inode(struct super_block *sb, ino_t *inop) if (!(sb->s_flags & SB_KERNMOUNT)) { spin_lock(&sbinfo->stat_lock); - if (!sbinfo->free_inodes) { - spin_unlock(&sbinfo->stat_lock); - return -ENOSPC; + if (sbinfo->max_inodes) { + if (!sbinfo->free_inodes) { + spin_unlock(&sbinfo->stat_lock); + return -ENOSPC; + } + sbinfo->free_inodes--; } - sbinfo->free_inodes--; if (inop) { ino = sbinfo->next_ino++; if (unlikely(is_zero_ino(ino)))
Commit e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") made changes to shmem_reserve_inode() in mm/shmem.c, however the original test for (sbinfo->max_inodes) got dropped. This causes mounting tmpfs with option nr_inodes=0 to fail: # mount -ttmpfs -onr_inodes=0 none /ext0 mount: /ext0: mount(2) system call failed: Cannot allocate memory. This patch restores the nr_inodes=0 functionality. Fixes: e809d5f0b5c9 ("tmpfs: per-superblock i_ino support") Cc: Chris Down <chris@chrisdown.name> Signed-off-by: Byron Stanoszek <gandalf@winds.org> --- mm/shmem.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)