| Message ID | 20190514135804.18669-1-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3.1,1/3] btrfs-progs: factor out super_block reading from load_and_dump_sb | expand |
On 14.05.19 г. 16:58 ч., Johannes Thumshirn wrote: > inspect-internal dump-superblock's load_and_dump_sb() already reads a > super block from a file descriptor and places it into a 'struct > btrfs_super_block'. > > For inspect-internal dump-csum we need this super block as well but don't > care about printing it. > > Separate the read from the dump phase so we can re-use it elsewhere. > > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> > --- > - Fix double sizeof() @!$#$ (Nikolay) > > cmds-inspect-dump-super.c | 15 ++++++--------- > utils.c | 15 +++++++++++++++ > utils.h | 2 ++ > 3 files changed, 23 insertions(+), 9 deletions(-) > > diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c > index 7815c863f2ed..879f979f526a 100644 > --- a/cmds-inspect-dump-super.c > +++ b/cmds-inspect-dump-super.c > @@ -477,16 +477,13 @@ static void dump_superblock(struct btrfs_super_block *sb, int full) > static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, > int force) > { > - u8 super_block_data[BTRFS_SUPER_INFO_SIZE]; > - struct btrfs_super_block *sb; > + struct btrfs_super_block sb; > u64 ret; > > - sb = (struct btrfs_super_block *)super_block_data; > - > - ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr); > - if (ret != BTRFS_SUPER_INFO_SIZE) { > + ret = load_sb(fd, sb_bytenr, &sb); > + if (ret) { > /* check if the disk if too short for further superblock */ > - if (ret == 0 && errno == 0) > + if (ret == -ENOSPC) > return 0; > > error("failed to read the superblock on %s at %llu", > @@ -496,11 +493,11 @@ static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, > } > printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename); > printf("---------------------------------------------------------\n"); > - if (btrfs_super_magic(sb) != BTRFS_MAGIC && !force) { > + if (btrfs_super_magic(&sb) != BTRFS_MAGIC && !force) { > error("bad magic on superblock on %s at %llu", > filename, (unsigned long long)sb_bytenr); > } else { > - dump_superblock(sb, full); > + dump_superblock(&sb, full); > } > return 0; > } > diff --git a/utils.c b/utils.c > index 9e26c884cc6c..f0ae53ded315 100644 > --- a/utils.c > +++ b/utils.c > @@ -2593,3 +2593,18 @@ void print_all_devices(struct list_head *devices) > print_device_info(dev, "\t"); > printf("\n"); > } > + > +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb) > +{ > + size_t size = sizeof(struct btrfs_super_block); > + int ret; > + > + ret = pread64(fd, sb, size, bytenr); > + if (ret != size) { > + if (ret == 0 && errno == 0) > + return -EINVAL; > + > + return -errno; > + } > + return 0; > +} > diff --git a/utils.h b/utils.h > index 7c5eb798557d..f0b9ec372893 100644 > --- a/utils.h > +++ b/utils.h > @@ -171,6 +171,8 @@ unsigned long total_memory(void); > void print_device_info(struct btrfs_device *device, char *prefix); > void print_all_devices(struct list_head *devices); > > +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb); > + > /* > * Global program state, configurable by command line and available to > * functions without extra context passing. >
On Tue, May 14, 2019 at 03:58:04PM +0200, Johannes Thumshirn wrote: > inspect-internal dump-superblock's load_and_dump_sb() already reads a > super block from a file descriptor and places it into a 'struct > btrfs_super_block'. > > For inspect-internal dump-csum we need this super block as well but don't > care about printing it. > > Separate the read from the dump phase so we can re-use it elsewhere. > > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > --- > - Fix double sizeof() @!$#$ (Nikolay) > > cmds-inspect-dump-super.c | 15 ++++++--------- > utils.c | 15 +++++++++++++++ > utils.h | 2 ++ > 3 files changed, 23 insertions(+), 9 deletions(-) > > diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c > index 7815c863f2ed..879f979f526a 100644 > --- a/cmds-inspect-dump-super.c > +++ b/cmds-inspect-dump-super.c > @@ -477,16 +477,13 @@ static void dump_superblock(struct btrfs_super_block *sb, int full) > static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, > int force) > { > - u8 super_block_data[BTRFS_SUPER_INFO_SIZE]; > - struct btrfs_super_block *sb; > + struct btrfs_super_block sb; > u64 ret; > > - sb = (struct btrfs_super_block *)super_block_data; > - > - ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr); > - if (ret != BTRFS_SUPER_INFO_SIZE) { > + ret = load_sb(fd, sb_bytenr, &sb); > + if (ret) { This is buggy. We need to copy the whole BTRFS_SUPER_INFO_SIZE and calculate the checksums over this area. Sorry, Johannes
diff --git a/cmds-inspect-dump-super.c b/cmds-inspect-dump-super.c index 7815c863f2ed..879f979f526a 100644 --- a/cmds-inspect-dump-super.c +++ b/cmds-inspect-dump-super.c @@ -477,16 +477,13 @@ static void dump_superblock(struct btrfs_super_block *sb, int full) static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, int force) { - u8 super_block_data[BTRFS_SUPER_INFO_SIZE]; - struct btrfs_super_block *sb; + struct btrfs_super_block sb; u64 ret; - sb = (struct btrfs_super_block *)super_block_data; - - ret = pread64(fd, super_block_data, BTRFS_SUPER_INFO_SIZE, sb_bytenr); - if (ret != BTRFS_SUPER_INFO_SIZE) { + ret = load_sb(fd, sb_bytenr, &sb); + if (ret) { /* check if the disk if too short for further superblock */ - if (ret == 0 && errno == 0) + if (ret == -ENOSPC) return 0; error("failed to read the superblock on %s at %llu", @@ -496,11 +493,11 @@ static int load_and_dump_sb(char *filename, int fd, u64 sb_bytenr, int full, } printf("superblock: bytenr=%llu, device=%s\n", sb_bytenr, filename); printf("---------------------------------------------------------\n"); - if (btrfs_super_magic(sb) != BTRFS_MAGIC && !force) { + if (btrfs_super_magic(&sb) != BTRFS_MAGIC && !force) { error("bad magic on superblock on %s at %llu", filename, (unsigned long long)sb_bytenr); } else { - dump_superblock(sb, full); + dump_superblock(&sb, full); } return 0; } diff --git a/utils.c b/utils.c index 9e26c884cc6c..f0ae53ded315 100644 --- a/utils.c +++ b/utils.c @@ -2593,3 +2593,18 @@ void print_all_devices(struct list_head *devices) print_device_info(dev, "\t"); printf("\n"); } + +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb) +{ + size_t size = sizeof(struct btrfs_super_block); + int ret; + + ret = pread64(fd, sb, size, bytenr); + if (ret != size) { + if (ret == 0 && errno == 0) + return -EINVAL; + + return -errno; + } + return 0; +} diff --git a/utils.h b/utils.h index 7c5eb798557d..f0b9ec372893 100644 --- a/utils.h +++ b/utils.h @@ -171,6 +171,8 @@ unsigned long total_memory(void); void print_device_info(struct btrfs_device *device, char *prefix); void print_all_devices(struct list_head *devices); +int load_sb(int fd, u64 bytenr, struct btrfs_super_block *sb); + /* * Global program state, configurable by command line and available to * functions without extra context passing.
inspect-internal dump-superblock's load_and_dump_sb() already reads a super block from a file descriptor and places it into a 'struct btrfs_super_block'. For inspect-internal dump-csum we need this super block as well but don't care about printing it. Separate the read from the dump phase so we can re-use it elsewhere. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> --- - Fix double sizeof() @!$#$ (Nikolay) cmds-inspect-dump-super.c | 15 ++++++--------- utils.c | 15 +++++++++++++++ utils.h | 2 ++ 3 files changed, 23 insertions(+), 9 deletions(-)