| Message ID | 20200129170310.51370-16-hch@lst.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [01/30] xfs: reject invalid flags combinations in XFS_IOC_ATTRLIST_BY_HANDLE | expand |
On Wednesday, January 29, 2020 10:32 PM Christoph Hellwig wrote: > Use a NULL args->value as the indicator to lazily allocate a buffer > instead, and let the caller always free args->value instead of > duplicating the cleanup. xfs_get_acl() now unconditionally invokes kmem_free() on args.value. This matches the requirement set by xfs_attr_get(). Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com> > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > fs/xfs/libxfs/xfs_attr.c | 20 +++++--------------- > fs/xfs/libxfs/xfs_attr.h | 7 ++----- > fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- > fs/xfs/libxfs/xfs_types.h | 2 -- > fs/xfs/xfs_acl.c | 20 ++++++++++---------- > 5 files changed, 18 insertions(+), 33 deletions(-) > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > index 469417786bfc..1382e51ef85e 100644 > --- a/fs/xfs/libxfs/xfs_attr.c > +++ b/fs/xfs/libxfs/xfs_attr.c > @@ -98,15 +98,14 @@ xfs_attr_get_ilocked( > * indication whether the attribute exists and the size of the value if it > * exists. The size is returned in args.valuelen. > * > + * If args->value is NULL but args->valuelen is non-zero, allocate the buffer > + * for the value after existence of the attribute has been determined. The > + * caller always has to free args->value if it is set, no matter if this > + * function was successful or not. > + * > * If the attribute is found, but exceeds the size limit set by the caller in > * args->valuelen, return -ERANGE with the size of the attribute that was found > * in args->valuelen. > - * > - * If ATTR_ALLOC is set in args->flags, allocate the buffer for the value after > - * existence of the attribute has been determined. On success, return that > - * buffer to the caller and leave them to free it. On failure, free any > - * allocated buffer and ensure the buffer pointer returned to the caller is > - * null. > */ > int > xfs_attr_get( > @@ -115,8 +114,6 @@ xfs_attr_get( > uint lock_mode; > int error; > > - ASSERT((args->flags & ATTR_ALLOC) || !args->valuelen || args->value); > - > XFS_STATS_INC(args->dp->i_mount, xs_attr_get); > > if (XFS_FORCED_SHUTDOWN(args->dp->i_mount)) > @@ -128,18 +125,11 @@ xfs_attr_get( > > /* Entirely possible to look up a name which doesn't exist */ > args->op_flags = XFS_DA_OP_OKNOENT; > - if (args->flags & ATTR_ALLOC) > - args->op_flags |= XFS_DA_OP_ALLOCVAL; > > lock_mode = xfs_ilock_attr_map_shared(args->dp); > error = xfs_attr_get_ilocked(args); > xfs_iunlock(args->dp, lock_mode); > > - /* on error, we have to clean up allocated value buffers */ > - if (error && (args->flags & ATTR_ALLOC)) { > - kmem_free(args->value); > - args->value = NULL; > - } > return error; > } > > diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h > index fe064cd81747..a6de050675c9 100644 > --- a/fs/xfs/libxfs/xfs_attr.h > +++ b/fs/xfs/libxfs/xfs_attr.h > @@ -35,10 +35,8 @@ struct xfs_attr_list_context; > > #define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */ > > -#define ATTR_ALLOC 0x8000 /* [kernel] allocate xattr buffer on demand */ > - > #define ATTR_KERNEL_FLAGS \ > - (ATTR_KERNOTIME | ATTR_ALLOC) > + (ATTR_KERNOTIME) > > #define XFS_ATTR_FLAGS \ > { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \ > @@ -47,8 +45,7 @@ struct xfs_attr_list_context; > { ATTR_SECURE, "SECURE" }, \ > { ATTR_CREATE, "CREATE" }, \ > { ATTR_REPLACE, "REPLACE" }, \ > - { ATTR_KERNOTIME, "KERNOTIME" }, \ > - { ATTR_ALLOC, "ALLOC" } > + { ATTR_KERNOTIME, "KERNOTIME" } > > /* > * The maximum size (into the kernel or returned from the kernel) of an > diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c > index 5e700dfc48a9..b0658eb8fbcc 100644 > --- a/fs/xfs/libxfs/xfs_attr_leaf.c > +++ b/fs/xfs/libxfs/xfs_attr_leaf.c > @@ -477,7 +477,7 @@ xfs_attr_copy_value( > return -ERANGE; > } > > - if (args->op_flags & XFS_DA_OP_ALLOCVAL) { > + if (!args->value) { > args->value = kmem_alloc_large(valuelen, 0); > if (!args->value) > return -ENOMEM; > diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h > index 634814dd1d10..3379ebc0c7c5 100644 > --- a/fs/xfs/libxfs/xfs_types.h > +++ b/fs/xfs/libxfs/xfs_types.h > @@ -223,7 +223,6 @@ typedef struct xfs_da_args { > #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */ > #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */ > #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */ > -#define XFS_DA_OP_ALLOCVAL 0x0020 /* lookup to alloc buffer if found */ > #define XFS_DA_OP_INCOMPLETE 0x0040 /* lookup INCOMPLETE attr keys */ > > #define XFS_DA_OP_FLAGS \ > @@ -232,7 +231,6 @@ typedef struct xfs_da_args { > { XFS_DA_OP_ADDNAME, "ADDNAME" }, \ > { XFS_DA_OP_OKNOENT, "OKNOENT" }, \ > { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \ > - { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }, \ > { XFS_DA_OP_INCOMPLETE, "INCOMPLETE" } > > /* > diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c > index 780924984492..bc78b7c33401 100644 > --- a/fs/xfs/xfs_acl.c > +++ b/fs/xfs/xfs_acl.c > @@ -125,7 +125,7 @@ xfs_get_acl(struct inode *inode, int type) > struct posix_acl *acl = NULL; > struct xfs_da_args args = { > .dp = ip, > - .flags = ATTR_ALLOC | ATTR_ROOT, > + .flags = ATTR_ROOT, > .valuelen = XFS_ACL_MAX_SIZE(mp), > }; > int error; > @@ -144,19 +144,19 @@ xfs_get_acl(struct inode *inode, int type) > } > args.namelen = strlen(args.name); > > + /* > + * If the attribute doesn't exist make sure we have a negative cache > + * entry, for any other error assume it is transient. > + */ > error = xfs_attr_get(&args); > - if (error) { > - /* > - * If the attribute doesn't exist make sure we have a negative > - * cache entry, for any other error assume it is transient. > - */ > - if (error != -ENOATTR) > - acl = ERR_PTR(error); > - } else { > + if (!error) { > acl = xfs_acl_from_disk(mp, args.value, args.valuelen, > XFS_ACL_MAX_ENTRIES(mp)); > - kmem_free(args.value); > + } else if (error != -ENOATTR) { > + acl = ERR_PTR(error); > } > + > + kmem_free(args.value); > return acl; > } > >
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index 469417786bfc..1382e51ef85e 100644 --- a/fs/xfs/libxfs/xfs_attr.c +++ b/fs/xfs/libxfs/xfs_attr.c @@ -98,15 +98,14 @@ xfs_attr_get_ilocked( * indication whether the attribute exists and the size of the value if it * exists. The size is returned in args.valuelen. * + * If args->value is NULL but args->valuelen is non-zero, allocate the buffer + * for the value after existence of the attribute has been determined. The + * caller always has to free args->value if it is set, no matter if this + * function was successful or not. + * * If the attribute is found, but exceeds the size limit set by the caller in * args->valuelen, return -ERANGE with the size of the attribute that was found * in args->valuelen. - * - * If ATTR_ALLOC is set in args->flags, allocate the buffer for the value after - * existence of the attribute has been determined. On success, return that - * buffer to the caller and leave them to free it. On failure, free any - * allocated buffer and ensure the buffer pointer returned to the caller is - * null. */ int xfs_attr_get( @@ -115,8 +114,6 @@ xfs_attr_get( uint lock_mode; int error; - ASSERT((args->flags & ATTR_ALLOC) || !args->valuelen || args->value); - XFS_STATS_INC(args->dp->i_mount, xs_attr_get); if (XFS_FORCED_SHUTDOWN(args->dp->i_mount)) @@ -128,18 +125,11 @@ xfs_attr_get( /* Entirely possible to look up a name which doesn't exist */ args->op_flags = XFS_DA_OP_OKNOENT; - if (args->flags & ATTR_ALLOC) - args->op_flags |= XFS_DA_OP_ALLOCVAL; lock_mode = xfs_ilock_attr_map_shared(args->dp); error = xfs_attr_get_ilocked(args); xfs_iunlock(args->dp, lock_mode); - /* on error, we have to clean up allocated value buffers */ - if (error && (args->flags & ATTR_ALLOC)) { - kmem_free(args->value); - args->value = NULL; - } return error; } diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h index fe064cd81747..a6de050675c9 100644 --- a/fs/xfs/libxfs/xfs_attr.h +++ b/fs/xfs/libxfs/xfs_attr.h @@ -35,10 +35,8 @@ struct xfs_attr_list_context; #define ATTR_KERNOTIME 0x1000 /* [kernel] don't update inode timestamps */ -#define ATTR_ALLOC 0x8000 /* [kernel] allocate xattr buffer on demand */ - #define ATTR_KERNEL_FLAGS \ - (ATTR_KERNOTIME | ATTR_ALLOC) + (ATTR_KERNOTIME) #define XFS_ATTR_FLAGS \ { ATTR_DONTFOLLOW, "DONTFOLLOW" }, \ @@ -47,8 +45,7 @@ struct xfs_attr_list_context; { ATTR_SECURE, "SECURE" }, \ { ATTR_CREATE, "CREATE" }, \ { ATTR_REPLACE, "REPLACE" }, \ - { ATTR_KERNOTIME, "KERNOTIME" }, \ - { ATTR_ALLOC, "ALLOC" } + { ATTR_KERNOTIME, "KERNOTIME" } /* * The maximum size (into the kernel or returned from the kernel) of an diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c index 5e700dfc48a9..b0658eb8fbcc 100644 --- a/fs/xfs/libxfs/xfs_attr_leaf.c +++ b/fs/xfs/libxfs/xfs_attr_leaf.c @@ -477,7 +477,7 @@ xfs_attr_copy_value( return -ERANGE; } - if (args->op_flags & XFS_DA_OP_ALLOCVAL) { + if (!args->value) { args->value = kmem_alloc_large(valuelen, 0); if (!args->value) return -ENOMEM; diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h index 634814dd1d10..3379ebc0c7c5 100644 --- a/fs/xfs/libxfs/xfs_types.h +++ b/fs/xfs/libxfs/xfs_types.h @@ -223,7 +223,6 @@ typedef struct xfs_da_args { #define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */ #define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */ #define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */ -#define XFS_DA_OP_ALLOCVAL 0x0020 /* lookup to alloc buffer if found */ #define XFS_DA_OP_INCOMPLETE 0x0040 /* lookup INCOMPLETE attr keys */ #define XFS_DA_OP_FLAGS \ @@ -232,7 +231,6 @@ typedef struct xfs_da_args { { XFS_DA_OP_ADDNAME, "ADDNAME" }, \ { XFS_DA_OP_OKNOENT, "OKNOENT" }, \ { XFS_DA_OP_CILOOKUP, "CILOOKUP" }, \ - { XFS_DA_OP_ALLOCVAL, "ALLOCVAL" }, \ { XFS_DA_OP_INCOMPLETE, "INCOMPLETE" } /* diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c index 780924984492..bc78b7c33401 100644 --- a/fs/xfs/xfs_acl.c +++ b/fs/xfs/xfs_acl.c @@ -125,7 +125,7 @@ xfs_get_acl(struct inode *inode, int type) struct posix_acl *acl = NULL; struct xfs_da_args args = { .dp = ip, - .flags = ATTR_ALLOC | ATTR_ROOT, + .flags = ATTR_ROOT, .valuelen = XFS_ACL_MAX_SIZE(mp), }; int error; @@ -144,19 +144,19 @@ xfs_get_acl(struct inode *inode, int type) } args.namelen = strlen(args.name); + /* + * If the attribute doesn't exist make sure we have a negative cache + * entry, for any other error assume it is transient. + */ error = xfs_attr_get(&args); - if (error) { - /* - * If the attribute doesn't exist make sure we have a negative - * cache entry, for any other error assume it is transient. - */ - if (error != -ENOATTR) - acl = ERR_PTR(error); - } else { + if (!error) { acl = xfs_acl_from_disk(mp, args.value, args.valuelen, XFS_ACL_MAX_ENTRIES(mp)); - kmem_free(args.value); + } else if (error != -ENOATTR) { + acl = ERR_PTR(error); } + + kmem_free(args.value); return acl; }
Use a NULL args->value as the indicator to lazily allocate a buffer instead, and let the caller always free args->value instead of duplicating the cleanup. Signed-off-by: Christoph Hellwig <hch@lst.de> --- fs/xfs/libxfs/xfs_attr.c | 20 +++++--------------- fs/xfs/libxfs/xfs_attr.h | 7 ++----- fs/xfs/libxfs/xfs_attr_leaf.c | 2 +- fs/xfs/libxfs/xfs_types.h | 2 -- fs/xfs/xfs_acl.c | 20 ++++++++++---------- 5 files changed, 18 insertions(+), 33 deletions(-)