* Re: [PATCH v2] tmpfs: allow decoding a file handle of an unlinked file [not found] <1510555438-28996-1-git-send-email-amir73il@gmail.com> @ 2018-01-05 15:40 ` Amir Goldstein 2018-01-27 22:02 ` Amir Goldstein 0 siblings, 1 reply; 3+ messages in thread From: Amir Goldstein @ 2018-01-05 15:40 UTC (permalink / raw) To: Hugh Dickins Cc: Jeff Layton, J . Bruce Fields, James Bottomley, overlayfs, linux-fsdevel, Al Viro, Miklos Szeredi, linux-mm On Mon, Nov 13, 2017 at 8:43 AM, Amir Goldstein <amir73il@gmail.com> wrote: > tmpfs uses the helper d_find_alias() to find a dentry from a decoded > inode, but d_find_alias() skips unhashed dentries, so unlinked files > cannot be decoded from a file handle. > > This can be reproduced using xfstests test program open_by_handle: > $ open_by handle -c /tmp/testdir > $ open_by_handle -dk /tmp/testdir > open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an > unlinked open file! > > To fix this, if d_find_alias() can't find a hashed alias, call > d_find_any_alias() to return an unhashed one. > > Cc: Hugh Dickins <hughd@google.com> > Cc: Al Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > --- > > Al, Miklos, > > Can either of you take this patch through your tree? > > Thanks, > Amir. > > Changes since v1: > - Prefer a hashed alias (James) > - Use existing d_find_any_alias() helper > > mm/shmem.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/mm/shmem.c b/mm/shmem.c > index 07a1d22807be..5d3fa4099f54 100644 > --- a/mm/shmem.c > +++ b/mm/shmem.c > @@ -3404,6 +3404,15 @@ static int shmem_match(struct inode *ino, void *vfh) > return ino->i_ino == inum && fh[0] == ino->i_generation; > } > > +/* Find any alias of inode, but prefer a hashed alias */ > +static struct dentry *shmem_find_alias(struct inode *inode) > +{ > + struct dentry *alias = d_find_alias(inode); > + > + return alias ?: d_find_any_alias(inode); > +} > + > + > static struct dentry *shmem_fh_to_dentry(struct super_block *sb, > struct fid *fid, int fh_len, int fh_type) > { > @@ -3420,7 +3429,7 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb, > inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), > shmem_match, fid->raw); > if (inode) { > - dentry = d_find_alias(inode); > + dentry = shmem_find_alias(inode); > iput(inode); > } > > -- Hugh, Did you get a chance to look at this patch? The test for decoding a file handle of an unlinked file has already been merged to xfstest generic/467 and the test is failing on tmpfs without this change. Can you please take or ACK this patch? Thanks, Amir. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] tmpfs: allow decoding a file handle of an unlinked file 2018-01-05 15:40 ` [PATCH v2] tmpfs: allow decoding a file handle of an unlinked file Amir Goldstein @ 2018-01-27 22:02 ` Amir Goldstein 2018-04-23 15:44 ` Amir Goldstein 0 siblings, 1 reply; 3+ messages in thread From: Amir Goldstein @ 2018-01-27 22:02 UTC (permalink / raw) To: Hugh Dickins, Al Viro Cc: Jeff Layton, J . Bruce Fields, James Bottomley, overlayfs, linux-fsdevel, Miklos Szeredi, Linux MM On Fri, Jan 5, 2018 at 5:40 PM, Amir Goldstein <amir73il@gmail.com> wrote: > On Mon, Nov 13, 2017 at 8:43 AM, Amir Goldstein <amir73il@gmail.com> wrote: >> tmpfs uses the helper d_find_alias() to find a dentry from a decoded >> inode, but d_find_alias() skips unhashed dentries, so unlinked files >> cannot be decoded from a file handle. >> >> This can be reproduced using xfstests test program open_by_handle: >> $ open_by handle -c /tmp/testdir >> $ open_by_handle -dk /tmp/testdir >> open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an >> unlinked open file! >> >> To fix this, if d_find_alias() can't find a hashed alias, call >> d_find_any_alias() to return an unhashed one. >> >> Cc: Hugh Dickins <hughd@google.com> >> Cc: Al Viro <viro@zeniv.linux.org.uk> >> Signed-off-by: Amir Goldstein <amir73il@gmail.com> >> --- >> >> Al, Miklos, >> >> Can either of you take this patch through your tree? >> >> Thanks, >> Amir. >> >> Changes since v1: >> - Prefer a hashed alias (James) >> - Use existing d_find_any_alias() helper >> >> mm/shmem.c | 11 ++++++++++- >> 1 file changed, 10 insertions(+), 1 deletion(-) >> >> diff --git a/mm/shmem.c b/mm/shmem.c >> index 07a1d22807be..5d3fa4099f54 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -3404,6 +3404,15 @@ static int shmem_match(struct inode *ino, void *vfh) >> return ino->i_ino == inum && fh[0] == ino->i_generation; >> } >> >> +/* Find any alias of inode, but prefer a hashed alias */ >> +static struct dentry *shmem_find_alias(struct inode *inode) >> +{ >> + struct dentry *alias = d_find_alias(inode); >> + >> + return alias ?: d_find_any_alias(inode); >> +} >> + >> + >> static struct dentry *shmem_fh_to_dentry(struct super_block *sb, >> struct fid *fid, int fh_len, int fh_type) >> { >> @@ -3420,7 +3429,7 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb, >> inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), >> shmem_match, fid->raw); >> if (inode) { >> - dentry = d_find_alias(inode); >> + dentry = shmem_find_alias(inode); >> iput(inode); >> } >> >> -- > > Hugh, > > Did you get a chance to look at this patch? > > The test for decoding a file handle of an unlinked file has already been > merged to xfstest generic/467 and the test is failing on tmpfs without this > change. > > Can you please take or ACK this patch? > Ping. Real problem. Trivial fix. Al, Can you take this patch? Thanks, Amir. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] tmpfs: allow decoding a file handle of an unlinked file 2018-01-27 22:02 ` Amir Goldstein @ 2018-04-23 15:44 ` Amir Goldstein 0 siblings, 0 replies; 3+ messages in thread From: Amir Goldstein @ 2018-04-23 15:44 UTC (permalink / raw) To: Hugh Dickins, Al Viro Cc: Jeff Layton, J . Bruce Fields, James Bottomley, overlayfs, linux-fsdevel, Miklos Szeredi, Linux MM On Sat, Jan 27, 2018 at 2:02 PM, Amir Goldstein <amir73il@gmail.com> wrote: > On Fri, Jan 5, 2018 at 5:40 PM, Amir Goldstein <amir73il@gmail.com> wrote: >> On Mon, Nov 13, 2017 at 8:43 AM, Amir Goldstein <amir73il@gmail.com> wrote: >>> tmpfs uses the helper d_find_alias() to find a dentry from a decoded >>> inode, but d_find_alias() skips unhashed dentries, so unlinked files >>> cannot be decoded from a file handle. >>> >>> This can be reproduced using xfstests test program open_by_handle: >>> $ open_by handle -c /tmp/testdir >>> $ open_by_handle -dk /tmp/testdir >>> open_by_handle(/tmp/testdir/file000000) returned 116 incorrectly on an >>> unlinked open file! >>> >>> To fix this, if d_find_alias() can't find a hashed alias, call >>> d_find_any_alias() to return an unhashed one. >>> >>> Cc: Hugh Dickins <hughd@google.com> >>> Cc: Al Viro <viro@zeniv.linux.org.uk> >>> Signed-off-by: Amir Goldstein <amir73il@gmail.com> >>> --- >>> >>> Al, Miklos, >>> >>> Can either of you take this patch through your tree? >>> >>> Thanks, >>> Amir. >>> >>> Changes since v1: >>> - Prefer a hashed alias (James) >>> - Use existing d_find_any_alias() helper >>> >>> mm/shmem.c | 11 ++++++++++- >>> 1 file changed, 10 insertions(+), 1 deletion(-) >>> >>> diff --git a/mm/shmem.c b/mm/shmem.c >>> index 07a1d22807be..5d3fa4099f54 100644 >>> --- a/mm/shmem.c >>> +++ b/mm/shmem.c >>> @@ -3404,6 +3404,15 @@ static int shmem_match(struct inode *ino, void *vfh) >>> return ino->i_ino == inum && fh[0] == ino->i_generation; >>> } >>> >>> +/* Find any alias of inode, but prefer a hashed alias */ >>> +static struct dentry *shmem_find_alias(struct inode *inode) >>> +{ >>> + struct dentry *alias = d_find_alias(inode); >>> + >>> + return alias ?: d_find_any_alias(inode); >>> +} >>> + >>> + >>> static struct dentry *shmem_fh_to_dentry(struct super_block *sb, >>> struct fid *fid, int fh_len, int fh_type) >>> { >>> @@ -3420,7 +3429,7 @@ static struct dentry *shmem_fh_to_dentry(struct super_block *sb, >>> inode = ilookup5(sb, (unsigned long)(inum + fid->raw[0]), >>> shmem_match, fid->raw); >>> if (inode) { >>> - dentry = d_find_alias(inode); >>> + dentry = shmem_find_alias(inode); >>> iput(inode); >>> } >>> >>> -- >> >> Hugh, >> >> Did you get a chance to look at this patch? >> >> The test for decoding a file handle of an unlinked file has already been >> merged to xfstest generic/467 and the test is failing on tmpfs without this >> change. >> >> Can you please take or ACK this patch? >> > > Ping. > Ping^2 ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-04-23 15:44 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <1510555438-28996-1-git-send-email-amir73il@gmail.com>
2018-01-05 15:40 ` [PATCH v2] tmpfs: allow decoding a file handle of an unlinked file Amir Goldstein
2018-01-27 22:02 ` Amir Goldstein
2018-04-23 15:44 ` Amir Goldstein
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).