* [PATCH] mtd: Make sure the device supports erase operations in mtd_erase()
@ 2018-01-22 9:38 Boris Brezillon
2018-01-23 8:00 ` Miquel Raynal
2018-02-17 8:38 ` Boris Brezillon
0 siblings, 2 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-01-22 9:38 UTC (permalink / raw)
To: David Woodhouse, Brian Norris, Boris Brezillon, Marek Vasut,
Richard Weinberger, Cyrille Pitchen, linux-mtd
Cc: Peter Pan, Frieder Schrempf, Miquel Raynal
Some devices do not implement ->_erase() or have an invalid ->erasesize
value. In this case, mtd_erase() should return -ENOTSUPP.
Note that the test is not done on the MTD_NO_ERASE flag because this
flag means 'erasing a block before writing to it is unnecessary',
not 'the erase operation is not supported'. Actually, some drivers are
setting the MTD_NO_ERASE flag but still implementing the ->_erase()
hook and setting a valid ->erasesize value.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
drivers/mtd/mtdcore.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index d7ab091b36b2..f24144cbc99c 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -971,10 +971,14 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
*/
int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
+ if (!mtd->erasesize || !mtd->_erase)
+ return -ENOTSUPP;
+
if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
return -EINVAL;
if (!(mtd->flags & MTD_WRITEABLE))
return -EROFS;
+
instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
if (!instr->len) {
instr->state = MTD_ERASE_DONE;
--
2.11.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: Make sure the device supports erase operations in mtd_erase()
2018-01-22 9:38 [PATCH] mtd: Make sure the device supports erase operations in mtd_erase() Boris Brezillon
@ 2018-01-23 8:00 ` Miquel Raynal
2018-01-23 10:24 ` Boris Brezillon
2018-02-17 8:38 ` Boris Brezillon
1 sibling, 1 reply; 4+ messages in thread
From: Miquel Raynal @ 2018-01-23 8:00 UTC (permalink / raw)
To: Boris Brezillon
Cc: David Woodhouse, Brian Norris, Marek Vasut, Richard Weinberger,
Cyrille Pitchen, linux-mtd, Peter Pan, Frieder Schrempf
Hello Boris,
On Mon, 22 Jan 2018 10:38:01 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> Some devices do not implement ->_erase() or have an invalid ->erasesize
> value. In this case, mtd_erase() should return -ENOTSUPP.
>
> Note that the test is not done on the MTD_NO_ERASE flag because this
> flag means 'erasing a block before writing to it is unnecessary',
> not 'the erase operation is not supported'. Actually, some drivers are
> setting the MTD_NO_ERASE flag but still implementing the ->_erase()
> hook and setting a valid ->erasesize value.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> drivers/mtd/mtdcore.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index d7ab091b36b2..f24144cbc99c 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -971,10 +971,14 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
> */
> int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
> {
> + if (!mtd->erasesize || !mtd->_erase)
> + return -ENOTSUPP;
> +
> if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
> return -EINVAL;
> if (!(mtd->flags & MTD_WRITEABLE))
> return -EROFS;
This remark is not inherent to this patch in particular but as we are
adding a new error path, I thought it might be interesting to also
patch:
- INFTL_formatblock() from inftlmount.c [1] (mtd_erase called twice)
- NFTL_formatblock() from nftlmount.c [2]
They both call mtd_erase() without checking the return code and then
error out only if instr->state == MTD_ERASE_FAILED, which has not been
set before quitting mtd_erase() in the conditions above. I guess the
right thing to do is to add another condition in both functions on the
return code of mtd_erase(). What do you think?
Otherwise:
Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Have a good day,
Miquèl
[1]
http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/inftlmount.c#L396
[2]
http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/nftlmount.c#L334
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: Make sure the device supports erase operations in mtd_erase()
2018-01-23 8:00 ` Miquel Raynal
@ 2018-01-23 10:24 ` Boris Brezillon
0 siblings, 0 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-01-23 10:24 UTC (permalink / raw)
To: Miquel Raynal
Cc: David Woodhouse, Brian Norris, Marek Vasut, Richard Weinberger,
Cyrille Pitchen, linux-mtd, Peter Pan, Frieder Schrempf
On Tue, 23 Jan 2018 09:00:46 +0100
Miquel Raynal <miquel.raynal@free-electrons.com> wrote:
> Hello Boris,
>
> On Mon, 22 Jan 2018 10:38:01 +0100
> Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
>
> > Some devices do not implement ->_erase() or have an invalid ->erasesize
> > value. In this case, mtd_erase() should return -ENOTSUPP.
> >
> > Note that the test is not done on the MTD_NO_ERASE flag because this
> > flag means 'erasing a block before writing to it is unnecessary',
> > not 'the erase operation is not supported'. Actually, some drivers are
> > setting the MTD_NO_ERASE flag but still implementing the ->_erase()
> > hook and setting a valid ->erasesize value.
> >
> > Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> > ---
> > drivers/mtd/mtdcore.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> > index d7ab091b36b2..f24144cbc99c 100644
> > --- a/drivers/mtd/mtdcore.c
> > +++ b/drivers/mtd/mtdcore.c
> > @@ -971,10 +971,14 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
> > */
> > int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
> > {
> > + if (!mtd->erasesize || !mtd->_erase)
> > + return -ENOTSUPP;
> > +
> > if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
> > return -EINVAL;
> > if (!(mtd->flags & MTD_WRITEABLE))
> > return -EROFS;
>
> This remark is not inherent to this patch in particular but as we are
> adding a new error path, I thought it might be interesting to also
> patch:
> - INFTL_formatblock() from inftlmount.c [1] (mtd_erase called twice)
> - NFTL_formatblock() from nftlmount.c [2]
>
> They both call mtd_erase() without checking the return code and then
> error out only if instr->state == MTD_ERASE_FAILED, which has not been
> set before quitting mtd_erase() in the conditions above. I guess the
> right thing to do is to add another condition in both functions on the
> return code of mtd_erase(). What do you think?
This sounds reasonable.
>
> Otherwise:
> Reviewed-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Thanks.
Boris
>
> Have a good day,
> Miquèl
>
> [1]
> http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/inftlmount.c#L396
> [2]
> http://elixir.free-electrons.com/linux/latest/source/drivers/mtd/nftlmount.c#L334
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mtd: Make sure the device supports erase operations in mtd_erase()
2018-01-22 9:38 [PATCH] mtd: Make sure the device supports erase operations in mtd_erase() Boris Brezillon
2018-01-23 8:00 ` Miquel Raynal
@ 2018-02-17 8:38 ` Boris Brezillon
1 sibling, 0 replies; 4+ messages in thread
From: Boris Brezillon @ 2018-02-17 8:38 UTC (permalink / raw)
To: Boris Brezillon
Cc: David Woodhouse, Brian Norris, Marek Vasut, Richard Weinberger,
Cyrille Pitchen, linux-mtd, Peter Pan, Frieder Schrempf,
Miquel Raynal
On Mon, 22 Jan 2018 10:38:01 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:
> Some devices do not implement ->_erase() or have an invalid ->erasesize
> value. In this case, mtd_erase() should return -ENOTSUPP.
>
> Note that the test is not done on the MTD_NO_ERASE flag because this
> flag means 'erasing a block before writing to it is unnecessary',
> not 'the erase operation is not supported'. Actually, some drivers are
> setting the MTD_NO_ERASE flag but still implementing the ->_erase()
> hook and setting a valid ->erasesize value.
Applied.
>
> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> drivers/mtd/mtdcore.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
> index d7ab091b36b2..f24144cbc99c 100644
> --- a/drivers/mtd/mtdcore.c
> +++ b/drivers/mtd/mtdcore.c
> @@ -971,10 +971,14 @@ EXPORT_SYMBOL_GPL(__put_mtd_device);
> */
> int mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
> {
> + if (!mtd->erasesize || !mtd->_erase)
> + return -ENOTSUPP;
> +
> if (instr->addr >= mtd->size || instr->len > mtd->size - instr->addr)
> return -EINVAL;
> if (!(mtd->flags & MTD_WRITEABLE))
> return -EROFS;
> +
> instr->fail_addr = MTD_FAIL_ADDR_UNKNOWN;
> if (!instr->len) {
> instr->state = MTD_ERASE_DONE;
--
Boris Brezillon, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
http://bootlin.com
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-01-22 9:38 [PATCH] mtd: Make sure the device supports erase operations in mtd_erase() Boris Brezillon
2018-01-23 8:00 ` Miquel Raynal
2018-01-23 10:24 ` Boris Brezillon
2018-02-17 8:38 ` Boris Brezillon
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